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Effects of angiotensin 1-7 on the actions of angiotensin II in the renal and mesenteric vasculature of hypertensive and streptozotocin-induced diabetic rats

Dharmani M, Mustafa MR, Achike FI, Sim MK

Eur J Pharmacol, 2007 Apr 30;561(1-3):144-50.
PMID: 17320855

Angiotensin 1-7, a heptapeptide derived from metabolism of either angiotensin I or angiotensin II, is a biologically active peptide of the renin-angiotensin system. The present study investigated the effect of angiotensin 1-7 on the vasopressor action of angiotensin II in the renal and mesenteric vasculature of Wistar-Kyoto (WKY) rats, spontaneously hypertensive rats (SHR) and streptozotocin-induced diabetic rats. Angiotensin II-induced dose-dependent vasoconstrictions in the renal vasculature. The pressor response was enhanced in the SHR and reduced in the streptozotocin-diabetic rat compared to WKY rats. Angiotensin 1-7 attenuated the angiotensin II pressor responses in the renal vasculature of WKY and SHR rats. However, the ability to reduce angiotensin II response was diminished in diabetic-induced rat kidneys. The effect of angiotensin 1-7 was not inhibited by 1-[(4-(Dimethylamino)-3-methylphenyl] methyl]-5-(diphenylacetyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid ditrifluoroacetate (PD123319), an angiotensin AT(2) receptor antagonist. (D-ALA(7))-Angiotensin I/II (1-7) (D-ALA) (an angiotensin 1-7 receptor antagonist), indomethacin (a cyclo-oxygenase inhibitor), and N(omega)-Nitro-L-Arginine Methyl Ester (L-NAME)(a nitric oxide synthetase inhibitor) abolished the attenuation by angiotensin 1-7 in both WKY rats and SHR, indicating that its action is mediated by angiotensin 1-7 receptor that is either coupled to the release of prostaglandins and/or nitric oxide. The vasopressor responses to angiotensin II in mesenteric vasculature bed was also dose-dependent but smaller in magnitude compared to the renal vasculature. The responses to angiotensin II were relatively smaller in SHR but no significant difference was observed between WKY and streptozotocin-induced diabetic rats. Angiotensin 1-7 attenuated the angiotensin II pressor responses in WKY, SHR and diabetic-induced mesenteric bed. The attenuation was observed at the lower concentrations of angiotensin II in WKY and diabetic-induced rats but at higher concentrations in SHR. Similar observation as in the renal vasculature was seen with PD123319, D-ALA, and L-NAME. Indomethacin reversed the attenuation by angiotensin 1-7 only in the SHR mesenteric vascular bed. The present findings support the regulatory role of angiotensin 1-7 in the renal and mesenteric vasculature, which is differentially altered in hypertension and diabetes.

Matched MeSH terms: Blood Pressure/drug effects
Development and validation of RP-HPLC-UV method for simultaneous determination of buparvaquone, atenolol, propranolol, quinidine and verapamil: a tool for the standardization of rat in situ intestinal permeability studies

Venkatesh G, Ramanathan S, Mansor SM, Nair NK, Sattar MA, Croft SL, et al.

J Pharm Biomed Anal, 2007 Mar 12;43(4):1546-51.
PMID: 17157469

A simple, sensitive and specific reversed phase high performance liquid chromatographic (RP-HPLC) method with UV detection at 251 nm was developed for simultaneous quantitation of buparvaquone (BPQ), atenolol, propranolol, quinidine and verapamil. The method was applicable in rat in situ intestinal permeability study to assess intestinal permeability of BPQ, a promising lead compound for Leishmania donovani infections. The method was validated on a C-4 column with mobile phase comprising ammonium acetate buffer (0.02 M, pH 3.5) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 ml/min. The retention times for atenolol, quinidine, propranolol, verapamil and BPQ were 4.30, 5.96, 6.55, 7.98 and 8.54 min, respectively. The calibration curves were linear (correlation coefficient > or =0.996) in the selected range of each analyte. The method is specific and sensitive with limit of quantitation of 15 microg/ml for atenolol, 0.8 microg/ml for quinidine, 5 microg/ml for propranolol, 10 microg/ml for verapamil and 200 ng/ml for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and all the analytes were found to be stable. This method is simple, reliable and can be routinely used for accurate permeability characterization.

Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
Efficacy and safety of dexmedetomidine versus morphine in post-operative cardiac surgery patients

Abd Aziz N, Chue MC, Yong CY, Hassan Y, Awaisu A, Hassan J, et al.

Int J Clin Pharm, 2011 Apr;33(2):150-4.
PMID: 21744187 DOI: 10.1007/s11096-011-9480-7

OBJECTIVE: To compare the efficacy of dexmedetomidine versus morphine as a sedative/analgesic among post-operative cardiac surgery patients.
METHOD: A randomized controlled open-label study was performed at the cardiothoracic intensive care unit of Penang Hospital, Malaysia. A total of 28 patients who underwent cardiac surgeries were randomly assigned to receive either dexmedetomidine or morphine. Both groups were similar in terms of preoperative baseline characteristics. Efficacy measures included sedation scores and pain intensity and requirements for additional sedative/analgesic. Mean heart rate and arterial blood pressure were used as safety measures. Other measures were additional inotropes, extubation time and other concurrent medications.
RESULTS: The mean dose of dexmedetomidine infused was 0.12 [SD 0.03] μg kg⁻¹ h⁻¹, while that of morphine was 13.2 [SD 5.84] μg kg⁻¹ h⁻¹. Dexmedetomidine group showed more benefits in sedation and pain levels, additional sedative/analgesic requirements, and extubation time. No significant differences between the two groups for the outcome measures, except heart rate, which was significantly lower in the dexmedetomidine group.
CONCLUSION: This preliminary study suggests that dexmedetomidine was at least comparable to morphine in terms of efficacy and safety among cardiac surgery patients. Further studies with larger samples are recommended in order to determine the significant effects of the outcome measures.

Matched MeSH terms: Blood Pressure/drug effects
Fulltext Differential responses to blood pressure and oxidative stress in streptozotocin-induced diabetic Wistar-Kyoto rats and spontaneously hypertensive rats: effects of antioxidant (honey) treatment

Erejuwa OO, Sulaiman SA, Wahab MS, Sirajudeen KN, Salleh MS, Gurtu S

Int J Mol Sci, 2011;12(3):1888-907.
PMID: 21673929 DOI: 10.3390/ijms12031888

Oxidative stress is implicated in the pathogenesis and/or complications of hypertension and/or diabetes mellitus. A combination of these disorders increases the risk of developing cardiovascular events. This study investigated the effects of streptozotocin (60 mg/kg; ip)-induced diabetes on blood pressure, oxidative stress and effects of honey on these parameters in the kidneys of streptozotocin-induced diabetic Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Diabetic WKY and SHR were randomized into four groups and received distilled water (0.5 mL) and honey (1.0 g/kg) orally once daily for three weeks. Control SHR had reduced malondialdehyde (MDA) and increased systolic blood pressure (SBP), catalase (CAT) activity, and total antioxidant status (TAS). SBP, activities of glutathione peroxidase (GPx) and glutathione reductase (GR) were elevated while TAS was reduced in diabetic WKY. In contrast, SBP, TAS, activities of GPx and GR were reduced in diabetic SHR. Antioxidant (honey) treatment further reduced SBP in diabetic SHR but not in diabetic WKY. It also increased TAS, GSH, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, activities of GPx and GR in diabetic SHR. These data suggest that differences in types, severity, and complications of diseases as well as strains may influence responses to blood pressure and oxidative stress.

Matched MeSH terms: Blood Pressure/drug effects*
Fulltext Ethnic disparities in metabolic syndrome in Malaysia: an analysis by risk factors

Tan AKG, Dunn RA, Yen ST

Metab Syndr Relat Disord, 2011 Dec;9(6):441-51.
PMID: 21815810 DOI: 10.1089/met.2011.0031

BACKGROUND: This study investigates ethnic disparities in metabolic syndrome in Malaysia.
METHODS: Data were obtained from the Malaysia Non-Communicable Disease Surveillance-1 (2005/2006). Logistic regressions of metabolic syndrome health risks on sociodemographic and health-lifestyle factors were conducted using a multiracial (Malay, Chinese, and Indian and other ethnic groups) sample of 2,366 individuals.
RESULTS: Among both males and females, the prevalence of metabolic syndrome amongst Indians was larger compared to both Malays and Chinese because Indians are more likely to exhibit central obesity, elevated fasting blood glucose, and low high-density lipoprotein cholesterol. We also found that Indians tend to engage in less physical activity and consume fewer fruits and vegetables than Malays and Chinese. Although education and family history of chronic disease are associated with metabolic syndrome status, differences in socioeconomic attributes do not explain ethnic disparities in metabolic syndrome incidence. The difference in metabolic syndrome prevalence between Chinese and Malays was not statistically significant. Whereas both groups exhibited similar obesity rates, ethnic Chinese were less likely to suffer from high fasting blood glucose.
CONCLUSIONS: Metabolic syndrome disproportionately affects Indians in Malaysia. Additionally, fasting blood glucose rates differ dramatically amongst ethnic groups. Attempts to decrease health disparities among ethnic groups in Malaysia will require greater attention to improving the metabolic health of Malays, especially Indians, by encouraging healthful lifestyle changes.
Study name: Malaysia Non-Communicable Disease Surveillance-1 (MyNCDS-1) survey

Matched MeSH terms: Blood Pressure/physiology
Fulltext Glycaemic control of diabetic patients in an urban primary health care setting in Sarawak: the Tanah Puteh Health Centre experience

Wong JS, Rahimah N

Med J Malaysia, 2004 Aug;59(3):411-7.
PMID: 15727390 MyJurnal

Achieving glycaemic goals in diabetics has always been a problem, especially in a developing country with inadequate facilities such as in Sarawak in Malaysia. There are no reported studies on the control of diabetes mellitus in a diabetic clinic in the primary health care setting in Sarawak. This paper describes the profile of 1031 patients treated in Klinik Kesihatan Tanah Puteh Health Centre. The mean age was 59 years, the mean BMI 27 kg/m2. There was a female preponderance and mainly type-2 diabetes. Mean HbA1c was 7.4%. Glycaemic control was optimal in 28% (HbA1c <6.5%), fair in 34% (HbA1c 6.5-7.5%) and poor in 38% (HbA1c >7.5%). Reasonable glycaemic control can be achieved in the primary health care setting in Sarawak.
Study site: Klinik Kesihatan Tanah Puteh, Sarawak, Malaysia

Matched MeSH terms: Blood Pressure/drug effects
Metabolic, immunological and clinical characteristics in newly diagnosed Asian diabetes patients aged 12-40 years

Pan CY, So WY, Khalid BA, Mohan V, Thai AC, Zimmet P, et al.

Diabet Med, 2004 Sep;21(9):1007-13.
PMID: 15317606 DOI: 10.1111/j.1464-5491.2004.01287.x

AIM: To describe the clinical, biochemical and immunological characteristics of young-onset diabetes in Asia.
METHODS: Clinical, biochemical and immunological variables were assessed in 919 newly diagnosed (duration less than 12 months) young onset Asian diabetic patients aged between 12 and 40 years. The subjects constituted 57% Chinese, 29% Indians and 14% Malays, recruited from diabetes centres in China, Hong Kong, India, Malaysia and Singapore.
RESULTS: The mean age (+/- sd) was 31.6 +/- 7.2 years, with the majority (66%) in the 31-40 years age group. Mean body mass index (BMI) (+/- sd) was 25.3 +/- 5.0 kg/m2 with 47% exceeding the suggested Asian cut-off point for obesity (BMI > or = 25). Ethnic difference in clinical characteristics included BMI, blood pressure, mode of treatment and degree of insulin resistance. Most patients had a clinical presentation of Type 2 diabetes. About 10% had a classical combination of ketotic presentation, presence of autoimmune-markers and documented insulin deficiency indicative of Type 1 diabetes. Forty-eight percent were receiving oral hypoglycaemic agents (OHAs) while 31% were on diet only, 18% were receiving insulin and 2% were on a combination of insulin and OHA.
CONCLUSION: Young onset diabetes patients in Asia represent a heterogeneous group in terms of their clinical and biochemical characteristics and classical Type 1 diabetes is relatively uncommon. The 5-year follow up study will determine the progress of these patients and help to clarify the natural history.

Matched MeSH terms: Blood Pressure/physiology
Outcome of severe traumatic brain injury: comparison of three monitoring approaches

Isa R, Wan Adnan WA, Ghazali G, Idris Z, Ghani AR, Sayuthi S, et al.

Neurosurg Focus, 2003 Dec 15;15(6):E1.
PMID: 15305837

The determination of cerebral perfusion pressure (CPP) is regarded as vital in monitoring patients with severe traumatic brain injury. Besides indicating the status of cerebral blood flow (CBF), it also reveals the status of intracranial pressure (ICP). The abnormal or suboptimal level of CPP is commonly correlated with high values of ICP and therefore with poor patient outcomes. Eighty-two patients were divided into three groups of patients receiving treatment based on CPP and CBF, ICP alone, and conservative methods during two different observation periods. The characteristics of these three groups were compared based on age, sex, time between injury and hospital arrival, Glasgow Coma Scale score, pupillary reaction to light, surgical intervention, and computerized tomography scanning findings according to the Marshall classification system. Only time between injury and arrival (p = 0.001) was statistically significant. There was a statistically significant difference in the proportions of good outcomes between the multimodality group compared with the group of patients that underwent a single intracranial-based monitoring method and the group that received no monitoring (p = 0.003) based on a disability rating scale after a follow up of 12 months. Death was the focus of outcome in this study in which the multimodality approach to monitoring had superior results.

Matched MeSH terms: Blood Pressure; Intracranial Pressure
Fulltext Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil

Leong XF, Mustafa MR, Das S, Jaarin K

Lipids Health Dis, 2010;9:66.
PMID: 20573259 DOI: 10.1186/1476-511X-9-66

Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil.

Matched MeSH terms: Blood Pressure/drug effects
Anterior and posterior segment changes in rat eyes with chronic steroid administration and their responsiveness to antiglaucoma drugs

Razali N, Agarwal R, Agarwal P, Kapitonova MY, Kannan Kutty M, Smirnov A, et al.

Eur J Pharmacol, 2015 Feb 15;749:73-80.
PMID: 25481859 DOI: 10.1016/j.ejphar.2014.11.029

Steroid-induced ocular hypertension (SIOH) is associated with topical and systemic use of steroids. However, SIOH-associated anterior and posterior segment morphological changes in rats have not been described widely. Here we describe the pattern of intraocular pressure (IOP) changes, quantitative assessment of trabecular meshwork (TM) and retinal morphological changes and changes in retinal redox status in response to chronic dexamethasone treatment in rats. We also evaluated the responsiveness of steroid-pretreated rat eyes to 5 different classes of antiglaucoma drugs that act by different mechanisms. Up to 80% of dexamethasone treated animals achieved significant and sustained IOP elevation. TM thickness was significantly increased and number of TM cells was significantly reduced in SIOH rats compared to the vehicle-treated rats. Quantitative assessment of retinal morphology showed significantly reduced thickness of ganglion cell layer (GCL) and inner retina (IR) in SIOH rats compared to vehicle-treated rats. Estimation of retinal antioxidants including catalase, superoxide dismutase and glutathione showed significantly increased retinal oxidative stress in SIOH animals. Furthermore, steroid-treated eyes showed significant IOP lowering in response to treatment with 5 different drug classes. This indicated the ability of SIOH eyes to respond to drugs acting by different mechanisms. In conclusion, SIOH was associated with significant morphological changes in TM and retina and retinal redox status. Additionally, SIOH eyes also showed IOP lowering in response to drugs that act by different mechanisms of action. Hence, SIOH rats appear to be an inexpensive and noninvasive model for studying the experimental antiglaucoma drugs for IOP lowering and neuroprotective effects.

Matched MeSH terms: Intraocular Pressure/drug effects
Functional contribution of α1D-adrenoceptors in the renal vasculature of left ventricular hypertrophy induced with isoprenaline and caffeine in Wistar-Kyoto rats

Ahmad A, Sattar MA, Rathore HA, Abdulla MH, Khan SA, Abdullah NA, et al.

Can J Physiol Pharmacol, 2014 Dec;92(12):1029-35.
PMID: 25403946 DOI: 10.1139/cjpp-2014-0236

This study investigated the role of α1D-adrenoceptor in the modulation of renal haemodynamics in rats with left ventricular hypertrophy (LVH). LVH was established in Wistar-Kyoto (WKY) rats with isoprenaline (5.0 mg · (kg body mass)(-1), by subcutaneous injection every 72 h) and caffeine (62 mg · L(-1) in drinking water, daily for 14 days). Renal vasoconstrictor responses were measured for noradrenaline (NA), phenylephrine (PE), and methoxamine (ME) before and immediately after low or high dose intrarenal infusions of BMY 7378, a selective α1D-adrenoceptor blocker. The rats with LVH had higher mean arterial blood pressure and circulating NA levels, but lower renal cortical blood perfusion compared with the control group (all P < 0.05). In the LVH group, the magnitude of the renal vasoconstrictor response to ME was blunted, but not the response to NA or PE (P < 0.05), compared with the control group (LVH vs. C, 38% vs. 50%). The magnitude of the drop in the vasoconstrictor responses to NA, PE, and ME in the presence of a higher dose of BMY 7378 was significantly greater in the LVH group compared with the control group (LVH vs. C, 45% vs. 25% for NA, 52% vs. 33% for PE, 66% vs. 53% for ME, all P < 0.05). These findings indicate an impaired renal vasoconstrictor response to adrenergic agonists during LVH. In addition, the α1D-adrenoceptor subtype plays a key role in the modulation of vascular responses in this diseased state.

Matched MeSH terms: Arterial Pressure/drug effects
Fulltext Transcription Factor CREB3L1 Regulates Endoplasmic Reticulum Stress Response Genes in the Osmotically Challenged Rat Hypothalamus

Greenwood M, Greenwood MP, Paton JF, Murphy D

PLoS One, 2015;10(4):e0124956.
PMID: 25915053 DOI: 10.1371/journal.pone.0124956

Arginine vasopressin (AVP) is synthesised in magnocellular neurons (MCNs) of supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus. In response to the hyperosmotic stressors of dehydration (complete fluid deprivation, DH) or salt loading (drinking 2% salt solution, SL), AVP synthesis increases in MCNs, which over-burdens the protein folding machinery in the endoplasmic reticulum (ER). ER stress and the unfolded protein response (UPR) are signaling pathways that improve ER function in response to the accumulation of misfold/unfold protein. We asked whether an ER stress response was activated in the SON and PVN of DH and SL rats. We observed increased mRNA expression for the immunoglobulin heavy chain binding protein (BiP), activating transcription factor 4 (Atf4), C/EBP-homologous protein (Chop), and cAMP responsive element binding protein 3 like 1 (Creb3l1) in both SON and PVN of DH and SL rats. Although we found no changes in the splicing pattern of X box-binding protein 1 (Xbp1), an increase in the level of the unspliced form of Xbp1 (Xbp1U) was observed in DH and SL rats. CREB3L1, a novel ER stress inducer, has been shown to be activated by ER stress to regulate the expression of target genes. We have previously shown that CREB3L1 is a transcriptional regulator of the AVP gene; however, a role for CREB3L1 in the response to ER stress has yet to be investigated in MCNs. Here, we used lentiviral vectors to introduce a dominant negative form of CREB3L1 (CREB3L1DN) in the rat SON. Expression of CREB3L1DN in the SON decreased Chop and Xbp1U mRNA levels, but not BiP and Atf4 transcript expression. CREB3L1 is thus implicated as a transcriptional mediator of the ER stress response in the osmotically stimulated SON.

Matched MeSH terms: Osmotic Pressure*
Ocular Surface Disease in Glaucoma: Effect of Polypharmacy and Preservatives

Ramli N, Supramaniam G, Samsudin A, Juana A, Zahari M, Choo MM

Optom Vis Sci, 2015 Sep;92(9):e222-6.
PMID: 25730335 DOI: 10.1097/OPX.0000000000000542

PURPOSE: To evaluate the prevalence of ocular surface disease (OSD) in glaucoma and nonglaucoma subjects using different clinical tests and to determine the effect of number of antiglaucoma medications and preservatives on OSD.
METHODS: This is a cross-sectional, case-comparison study at the Eye Clinic of the University of Malaya Medical Centre, Malaysia, between June 2012 and January 2013. Glaucoma subjects (n = 105) using topical antiglaucoma medications were compared with control subjects (n = 102) who were not on any topical medications. The presence of OSD was assessed using the tear film breakup time (TBUT) test, corneal staining, Schirmer test, and Ocular Surface Disease Index (OSDI) questionnaire grading.
RESULTS: The prevalence of OSD varied from 37 to 91% in the glaucoma group, depending on the type of clinical test. More subjects in the glaucoma group had corneal staining (63% vs. 36%, p = 0.004), abnormal Schirmer tests (39% vs. 25%, p = 0.049), and moderate OSDI symptoms (17% vs. 7%, p = 0.028). The percentage with abnormal TBUT increased with higher numbers of topical medications and was high with both benzalkonium chloride-containing and preservative-free eye drops (90% and 94%, respectively, both p < 0.001). Benzalkonium chloride was associated with a nearly three times higher odds ratio of showing abnormal OSDI.
CONCLUSIONS: Ocular surface disease is common in those using topical antiglaucoma medications. Abnormal TBUT is associated with increasing number of eye drops and benzalkonium chloride-containing eye drops, although this also occurs with the use of preservative-free eye drops.
Study site: Eye Clinic, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia,

Matched MeSH terms: Intraocular Pressure/drug effects
Hydrogen sulphide and tempol treatments improve the blood pressure and renal excretory responses in spontaneously hypertensive rats

Ahmad FU, Sattar MA, Rathore HA, Tan YC, Akhtar S, Jin OH, et al.

Ren Fail, 2014 May;36(4):598-605.
PMID: 24502512 DOI: 10.3109/0886022X.2014.882218

Oxidative stress and suppressed H2S production lead to increased renal vascular resistance, disturbed glomerular hemodynamics, and abnormal renal sodium and water handling, contribute to the pathogenesis and maintenance of essential hypertension in man and the spontaneously hypertensive rat. This study investigated the impact of H2S and tempol alone and in combination on blood pressure and renal hemodynamics and excretory functions in the SHR. Groups of WKY rats or SHR (n=6) were treated for 4 weeks either as controls or received NaHS (SHR+NaHS), tempol (SHR+Tempol), or NaHS plus tempol (SHR+NaHS +Tempol). Metabolic studies were performed on days 0, 14, and 28, thereafter animals were anaesthetized to measure renal hemodynamics and plasma oxidative and antioxidant markers. SHR control rats had higher mean arterial blood pressure (140.0 ± 2 vs. 100.0 ± 3 mmHg), lower plasma and urinary H2S, creatinine clearance, urine flow rate and urinary sodium excretion, and oxidative stress compared to WKY (all p<0.05). Treatment either with NaHS or with tempol alone decreased blood pressure and oxidative stress and improved renal hemodynamic and excretory function compared to untreated SHR. Combined NaHS and tempol therapy in SHRs caused larger decreases in blood pressure (∼20-22% vs. ∼11-15% and ∼10-14%), increases in creatinine clearance, urinary sodium excretion and fractional sodium excretion and up-regulated the antioxidant status compared to each agent alone (all p<0.05). These findings demonstrated that H2S and tempol together resulted in greater reductions in blood pressure and normalization of kidney function compared with either compound alone.

Matched MeSH terms: Blood Pressure/drug effects*
The effects of tempol on renal function and hemodynamics in cyclosporine-induced renal insufficiency rats

Chia TY, Sattar MA, Abdulla MH, Rathore HA, Ahmad Fu, Kaur G, et al.

Ren Fail, 2013 Aug;35(7):978-88.
PMID: 23822648 DOI: 10.3109/0886022X.2013.809563

This study investigated the effects of tempol, a superoxide dismutase (SOD) mimetic and L-NAME, a nitric oxide (NO) synthase inhibitor on the renal function and hemodynamics in cyclosporine A (CsA) induced renal insufficiency rats. Male Sprague-Dawley rats were treated with either vehicle (C), tempol (T, 1 mmol/L in drinking fluid), L-NAME (L, 1 mmol/L in drinking fluid), CsA (Cs, 25 mg/kg/day via gavage), CsA plus tempol (TCs), CsA plus L-NAME (LCs) or CsA plus a combination of tempol and L-NAME (TLCs) for 21 consecutive days. At the end of treatment regimen, the renal responses to noradrenaline (NA), phenylephrine (PE), methoxamine and angiotensin II (Ang II) were determined. Cs and LCs rats had lower creatinine clearance (0.7 ± 0.1 and 0.6 ± 0.5 vs. 1.3 ± 0.2 mL/min/kg) and fractional excretion of sodium (0.12 ± 0.02 and 0.17 ± 0.01 vs. 0.67 ± 0.04%) but higher systolic blood pressure (145 ± 2 and 178 ± 4 vs. 116 ± 2) compared to the control (all p

Matched MeSH terms: Blood Pressure/drug effects
Fulltext Effect of Clonidine (an antihypertensive drug) treatment on oxidative stress markers in the heart of spontaneously hypertensive rats

Nik Yusoff NS, Mustapha Z, Govindasamy C, Sirajudeen KN

Oxid Med Cell Longev, 2013;2013:927214.
PMID: 23766863 DOI: 10.1155/2013/927214

Hypertension is a risk factor for several cardiovascular diseases and oxidative stress suggested to be involved in the pathophysiology. Antihypertensive drug Clonidine action in ameliorating oxidative stress was not well studied. Therefore, this study investigate the effect of Clonidine on oxidative stress markers and nitric oxide (NO) in SHR and nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME) administered SHR. Male rats were divided into four groups [SHR, SHR+Clonidine (SHR-C), SHR+L-NAME, SHR+Clonidine+L-NAME(SHRC+L-NAME)]. Rats (SHRC) were administered with Clonidine (0.5 mg kg(-1) day(-1)) from 4 weeks to 28 weeks in drinking water and L-NAME (25 mg kg(-1) day(-1)) from 16 weeks to 28 weeks to SHRC+L-NAME. Systolic blood pressure (SBP) was measured. At the end of 28 weeks, all rats were sacrificed and in their heart homogenate, oxidative stress parameters and NO was assessed. Clonidine treatment significantly enhanced the total antioxidant status (TAS) (P < 0.001) and reduced the thibarbituric acid reactive substances (TBARS) (P < 0.001) and protein carbonyl content (PCO) (P < 0.05). These data suggest that oxidative stress is involved in the hypertensive organ damage and Clonidine not only lowers the SBP but also ameliorated the oxidative stress in the heart of SHR and SHR+L-NAME.

Matched MeSH terms: Blood Pressure/drug effects
Fulltext Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

Jaarin K, Foong WD, Yeoh MH, Kamarul ZY, Qodriyah HM, Azman A, et al.

Clinics (Sao Paulo), 2015 Nov;70(11):751-7.
PMID: 26602523 DOI: 10.6061/clinics/2015(11)07

This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers.

Matched MeSH terms: Blood Pressure/drug effects*
Fulltext Transcription factor CREB3L1 mediates cAMP and glucocorticoid regulation of arginine vasopressin gene transcription in the rat hypothalamus

Greenwood M, Greenwood MP, Mecawi AS, Loh SY, Rodrigues JA, Paton JF, et al.

Mol Brain, 2015 Oct 26;8(1):68.
PMID: 26503226 DOI: 10.1186/s13041-015-0159-1

BACKGROUND: Arginine vasopressin (AVP), a neuropeptide hormone that functions in the regulation of water homeostasis by controlling water re-absorption at kidneys, is synthesised in supraoptic nucleus and paraventricular nucleus of the hypothalamus. An increase in plasma osmolality stimulates secretion of AVP to blood circulation and induces AVP synthesis in these nuclei. Although studies on mechanism of AVP transcriptional regulation in hypothalamus proposed that cAMP and glucocorticoids positively and negatively regulate Avp expression, respectively, the molecular mechanisms have remained elusive. Recently, we identified CREB3L1 (cAMP-responsive element binding protein 3 like 1) as a putative transcription factor of Avp transcription in the rat hypothalamus. However the mechanism of how CREB3L1 is regulated in response of hyperosmotic stress in the neurons of hypothalamus has never been reported. This study aims to investigate effect of previously reported regulators (cAMP and glucocorticoid) of Avp transcription on transcription factor CREB3L1 in order to establish a molecular explanation for cAMP and glucocorticoids effect on AVP expression.
RESULTS: The effect of cAMP and glucocorticoid treatment on Creb3l1 was investigated in both AtT20 cells and hypothalamic organotypic cultures. The expression of Creb3l1 was increased in both mRNA and protein level by treatment with forskolin, which raises intracellular cAMP levels. Activation of cAMP by forskolin also increased Avp promoter activity in AtT20 cells and this effect was blunted by shRNA mediated silencing of Creb3l1. The forskolin induced increase in Creb3l1 expression was diminished by combined treatment with dexamethasone, and, in vivo, intraperitoneal dexamethasone injection blunted the increase in Creb3l1 and Avp expression induced by hyperosmotic stress.
CONCLUSION: Here we shows that cAMP and glucocorticoid positively and negatively regulate Creb3l1 expression in the rat hypothalamus, respectively, and regulation of cAMP on AVP expression is mediated through CREB3L1. This data provides the connection between CREB3L1, a newly identified transcription factor of AVP expression, with the previously proposed mechanism of Avp transcription which extends our understanding in transcription regulation of Avp in the hypothalamus.

Matched MeSH terms: Osmotic Pressure/drug effects
Topical trans-resveratrol ameliorates steroid-induced anterior and posterior segment changes in rats

Razali N, Agarwal R, Agarwal P, Tripathy M, Kapitonova MY, Kutty MK, et al.

Exp Eye Res, 2016 Feb;143:9-16.
PMID: 26424219 DOI: 10.1016/j.exer.2015.09.014

Steroid-induced hypertension and glaucoma is associated with increased extracellular meshwork (ECM) deposition in trabecular meshwork (TM). Previous studies have shown that single drop application of trans-resveratrol lowers IOP in steroid-induced ocular hypertensive (SIOH) rats. This IOP lowering is attributed to activation of adenosine A1 receptors, which may lead to increased matrix metalloproteinase (MMP)-2 activity. This study evaluated the effect of repeated topical application of trans-resveratrol for 21 days in SIOH animals on IOP, changes in MMP-2 level in aqueous humor, trabecular meshwork and retinal morphology and retinal redox status. We observed that treatment with trans-resveratrol results in significant and sustained IOP reduction in SIOH rats. This IOP reduction is associated with significantly higher aqueous humor total MMP-2 level; significantly reduced TM thickness and increased number of TM cells. Treatment with trans-resveratrol also significantly increased ganglion cell layer (GCL) thickness, the linear cell density in the GCL and inner retina thickness; and significantly reduced retinal oxidative stress compared to the SIOH vehicle-treated group. In conclusion, repeated dose topical application of trans-resveratrol produces sustained IOP lowering effect, which is associated with increased level of aqueous humor MMP-2, normalization of TM and retinal morphology and restoration of retinal redox status.

Matched MeSH terms: Intraocular Pressure/drug effects*
Renoprotective and antihypertensive mechanism of action of Clinacanthus nutans bioactive polysaccharides by suppression of reactive oxygen species/ nuclear factor/ matrix metalloproteinase (ROS/NF-ΚB/MMP-9) and upregulation of endothelial nitric oxide synthase/nitric oxide (eNOS/NO) pathways

Chia TY, Gan CY, Cheah PS, Murugaiyah V, Fatima T, Haji EM, et al.

J Mol Histol, 2025 Jun 28;56(4):209.
PMID: 40580398 DOI: 10.1007/s10735-025-10481-9

Clinacanthus nutans (C. nutans) Lindau, is classified as a top herb which are investigated for different biological activities like antioxidant, anti-inflammatory and vasodilatory effects. Hitherto, no dedicated study has been investigated on the role of C. nutans in L-NAME [N(ω)-nitro-L-arginine methyl ester] in-vivo rat model to explore its antihypertensive and renoprotective mechanism by modulating the ROS/NF-κB/MMP-9 pathways both globally in the plasma as well as locally in the kidney by using in-vitro expression study. Present study hypothesized that bioactive polysaccharides leaves of the alcoholic extract of C. nutans (CNBP) could improve the functions of the kidney by its antioxidant, anti-inflammatory, antihypertensive actions by suppression of ROS/NF-κB/MMP-9 and upregulation of eNOS/NO pathways in the plasma and kidney. Thirty male Sprague-Dawley (SD) rats (n = 6) were randomised into five groups namely: Control (C), L-NAME (L) administered in drinking water, L-NAME + 500 mg/kg of C. nutans bioactive polysaccharides (CNBP) (LCN500), L-NAME + 1000 mg/kg of CNBP (LCN1000) and L-NAME + 2000 mg/kg of CNBP (LCN2000) respectively. All treatments were continued for the period of 14 days and physiological data like water intake, urine output, body weight was collected on days 0, 7 and 14. Acute in-vivo study was performed after cannulation of the femoral and carotid arteries where renal cortical blood perfusion (RCBP) was measured along with pulse wave velocity (PWV). Plasma and renal malondialdehyde (MDA), tumour necrosis factor-α(TNF-α), interleukin-6 (IL-6), matrix metalloproteinase-9 (MMP-9), intercellular adhesion molecule-1 (ICAM-1), nitric oxide synthase-1 (NOS1) and superoxide dismutase (SOD) were measured. Histopathological studies were done on the kidney tissue at the termination of experiment. Administrations of L-NAME to L group for 14 days resulted in significantly reduced levels of SOD and NOS while significantly elevated levels of MDA, TNF-α, IL-6 and MMP-9 in both plasma and kidney tissue when compared to control group (C). Conversely, treatment of 500, 1000 and 2000 mg/kg of CNBP has significantly reversed the values when same was compared to normal control ( C) group. Administration of L-NAME to L group for 14 days caused significantly increased systolic blood pressure (SBP) and arterial stiffness by increasing the pulse wave velocity (PWV) along with reduced creatinine clearance and renal cortical blood perfusion (RCBP) when compared to C group. Nevertheless, treatment of 500, 1000 and 2000 mg/kg CNBP has significantly reduced the SBP and PWV and raised the creatine clearance and RCBP functions when compared to (L) group. This study devised with the novel findings of 14 days CNBP treatment has suppressed ROS/TNF-α/MMP-9 pathway in the plasma and kidney which is pathological pathway for the kidney injury and hypertension while upregulated eNOS/NO pathways in plasma and kidney which is renoprotective and antihypertensive pathway in L-NAME rat model of hypertension and kidney injury.

Matched MeSH terms: Blood Pressure/drug effects

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