Displaying publications 61 - 80 of 2663 in total

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  1. Rahim SM, Taha EM, Al-janabi MS, Al-douri BI, Simon KD, Mazlan AG
    PMID: 25435631
    BACKGROUND: Cymbopogon citratus (Poaceae) a tropical perennial herb plant that is widely cultivated to be eaten either fresh with food or dried in tea or soft drink has been reported to possess a number of medicinal and aromatic properties. This study aimed at evaluating the protective effects of C. citratus aqueous extract against liver injury induced by hydrogen peroxide (H2O2), in male rats.

    MATERIALS AND METHODS: Twenty-five rats were randomly divided into five different groups of five animals in each group; (1) Control. (2) Received H2O2 (0.5%) with drinking water. (3), and (4) received H2O2 and C. citratus (100 mg·kg(-1) b wt), vitamin C (250 mg·kg(-1) b wt) respectively. (5), was given C. citratus alone. The treatments were administered for 30 days. Blood samples were collected and serum was used for biochemical assay including liver enzymes activities, total protein, total bilirubin and malonaldehyde, glutathione in serum and liver homogenates. Liver was excised and routinely processed for histological examinations.

    RESULTS: C. citratus attenuated liver damage due to H2O2 administration as indicated by the significant reduction (p<0.05), in the elevated levels of ALT, AST, ALP, LDH, TB, and MDA in serum and liver homogenates; increase in TP and GSH levels in serum and liver homogenates; and improvement of liver histo-pathological changes. These effects of the extract were similar to that of vitamin C which used as antioxidant reference.

    CONCLUSION: C. citratus could effectively ameliorate H2O2-induced oxidative stress and prevent liver injury in male rats.

    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  2. Mohamed M, Sulaiman SA, Jaafar H
    PMID: 23983363
    The effect of cigarette smoke (CS) on histology of male accessory reproductive organs and the possible protective effect of honey supplementation in rats were investigated in this study. Rats received distilled water, honey, CS exposure or honey plus CS exposure. Honey (1.2 g/kg body weight/day) was administered by gavage and CS exposure (3 times per day) was done in a chamber for 13 weeks. CS exposure significantly increased relative weight of epididymis and ventral prostate. There were also significantly increased number of clear cells and epithelial height of cauda epididymis as well as severe interstitial oedema and decreased epithelial height of prostate gland. However, with the supplementation of honey, these histological changes were significantly reversed suggesting the protective effect of honey against the toxic effect of CS on male accessory reproductive organs in rats.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  3. Anbu JS, Jayaraj P, Varatharajan R, Thomas J, Jisha J, Muthappan M
    Afr J Tradit Complement Altern Med, 2009 Jul 03;6(4):529-33.
    PMID: 20606773
    The ethanol and water extracts of Sansevieria trifasciata leaves showed dose-dependent and significant (P < 0.05) increase in pain threshold in tail-immersion test. Moreover, both the extracts (100 - 200 mg/kg) exhibited a dose-dependent inhibition of writhing and also showed a significant (P < 0.001) inhibition of both phases of the formalin pain test. The ethanol extract (200 mg/kg) significantly (P < 0.01) reversed yeast-induced fever. Preliminary phytochemical screening of the extracts showed the presence of alkaloids, flavonoids, saponins, glycosides, terpenoids, tannins, proteins and carbohydrates.
    Matched MeSH terms: Rats, Wistar; Rats
  4. Thent ZC, Lin TS, Das S, Zakaria Z
    PMID: 23983373
    Cardiovascular complications are one of the major causes of death in diabetes mellitus. Piper sarmentosum (P.s) is an herb that possesses antihyperglycaemic effects. The main aim of the study was to observe the histological changes in the heart and the proximal aorta of streptozotocin-induced diabetic rats following P.s administration. Twenty-four male Sprague-Dawley rats (n=24) were equally randomized into four groups: control group supplemented with normal saline (C); control group supplemented with P.s (CTx) ; diabetic group supplemented with normal saline (D) and, diabetic group supplemented with P.s (DTx). Diabetes was induced by STZ (50mg/kg body weight) intramuscularly. P.s extract (0.125g/kg) was administered orally for 28 days, following four weeks of STZ induction. The cardiac and aortic tissues were collected and processed under different stains: Haematoxylin and Eosin (H & E), Verhoeff-Van Gieson (VVG), Masson's Trichome (MT) and Periodic Acid- Schiff (PAS). There were abnormal cardiomyocytes nuclei, disarray of myofibres and increase in connective tissue deposits in cardiac tissues of the diabetic untreated group. The thickness of tunica media and ratio of tunica intima to media were found to be significantly increased in the aorta of diabetic untreated group (P < 0.05) compared to the control group. There were degenerative changes in the proximal aorta in diabetic untreated groups. All the histological damages of cardiac and aortic tissues were found to be lesser in the diabetic treated groups. Supplementation with P.s extract prevented the oxidative damage arising from diabetes mellitus, and reduced its complications.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  5. Jamila N, Khan N, Khan AA, Khan I, Khan SN, Zakaria ZA, et al.
    PMID: 28573253 DOI: 10.21010/ajtcam.v14i2.38
    BACKGROUND: Garcinia hombroniana, known as "manggis hutan" (jungle mangosteen) in Malaysia, is distributed in tropical Asia, Borneo, Thailand, Andaman, Nicobar Islands, Vietnam and India. In Malaysia, its ripened crimson sour fruit rind is used as a seasoning agent in curries and culinary dishes. Its roots and leaves decoction is used against skin infections and after child birth. This study aimed to evaluate in vivo hepatoprotective and in vitro cytotoxic activities of 20% methanolic ethyl acetate (MEA) G. hombroniana bark extract.

    MATERIALS AND METHODS: In hepatoprotective activity, liver damage was induced by treating rats with 1.0 mL carbon tetrachloride (CCl4)/kg and MEA extract was administered at a dose of 50, 250 and 500 mg/kg 24 h before intoxication with CCl4. Cytotoxicity study was performed on MCF-7 (human breast cancer), DBTRG (human glioblastoma), PC-3 (human prostate cancer) and U2OS (human osteosarcoma) cell lines. 1H, 13C-NMR (nuclear magnetic resonance), and IR (infrared) spectral analyses were also conducted for MEA extract.

    RESULTS: In hepatoprotective activity evaluation, MEA extract at a higher dose level of 500 mg/kg showed significant (p<0.05) potency. In cytotoxicity study, MEA extract was more toxic towards MCF-7 and DBTRG cell lines causing 78.7% and 64.3% cell death, respectively. MEA extract in 1H, 13C-NMR, and IR spectra exhibited bands, signals and J (coupling constant) values representing aromatic/phenolic constituents.

    CONCLUSIONS: From the results, it could be concluded that MEA extract has potency to inhibit hepatotoxicity and MCF-7 and DBTRG cancer cell lines which might be due to the phenolic compounds depicted from NMR and IR spectra.

    Matched MeSH terms: Rats, Sprague-Dawley
  6. Ahad MA, Chear NJ, Keat LG, Has ATC, Murugaiyah V, Hassan Z
    Ageing Res Rev, 2023 Aug;89:101990.
    PMID: 37343678 DOI: 10.1016/j.arr.2023.101990
    Research employing a bio-enhanced fraction of Clitoria ternatea (CT) to treat cognitive decline in the animal model has not yet been found. This study aimed to determine the neuroprotective effect of CT root bioactive fraction (CTRF) in chronic cerebral hypoperfusion (CCH) rat model. CTRF and its major compound, clitorienolactones A (CLA), were obtained using column chromatography. A validated HPLC-UV method was employed for the standardization of CTRF. CCH rats were given orally either vehicle or fraction (10, 20 and 40 mg/kg). Behavioural and hippocampal neuroplasticity studies were conducted following 4 weeks post-surgery. The brain hippocampus was extracted for proteins and neurotransmitters analyses. HPLC analysis showed that CTRF contained 25% (w/w) of CLA. All tested doses of CTRF and CLA (10 mg/kg) significantly restored cognitive deficits and reversed the inhibition of neuroplasticity by CCH. However, only CTRF (40 mg/kg) and CLA (10 mg/kg) significantly reversed the elevation of amyloid-beta plaque. Subsequently, treatment with CTRF (40 mg/kg) and CLA (10 mg/kg) alleviated the downregulation of molecular synaptic signalling proteins levels caused by CCH. The neurotransmitters level was restored following treatment of CTRF and CLA. Our finding suggested that CTRF improves memory and neuroplasticity in CCH rats which was mainly contributed by CLA.
    Matched MeSH terms: Rats
  7. Ahad MA, Chear NJ, Abdullah MH, Ching-Ga TAF, Liao P, Wei S, et al.
    Ageing Res Rev, 2024 Apr;96:102252.
    PMID: 38442748 DOI: 10.1016/j.arr.2024.102252
    Chronic cerebral hypoperfusion (CCH) is a common mechanism of acute brain injury due to impairment of blood flow to the brain. Moreover, a prolonged lack of oxygen supply may result in cerebral infarction or global ischemia, which subsequently causes long-term memory impairment. Research on using Clitoria ternatea root extract for treating long-term memory has been studied extensively. However, the bioactive compound contributing to its neuroprotective effects remains uncertain. In the present study, we investigate the effects of clitorienolactone A (CLA) and B (CLB) from the roots of Clitoria ternatea extract on hippocampal neuroplasticity in rats induced by CCH. CLA and CLB were obtained using column chromatography. The rat model of CCH was induced using two-vessel occlusion surgery (2VO). The 2VO rats were given 10 mg/kg of CLA and CLB orally, followed by hippocampal neuroplasticity recording using in vivo electrophysiological. Rats received CLA and CLB (10 mg/kg) significantly reversed the impairment of long-term potentiation following 2VO surgery. Furthermore, we investigate the effect of CLA and CLB on the calcium channel using the calcium imaging technique. During hypoxia, CLA and CLB sustain the increase in intracellular calcium levels. We next predict the binding interactions of CLA and CLB against NMDA receptors containing GluN2A and GluN2B subunits using in silico molecular docking. Our result found that both CLA and CLB exhibited lower binding affinity against GluN2A and GluN2B subunits. Our findings demonstrated that bioactive compounds from Clitoria ternatea improved long-term memory deficits in the chronic cerebral hypoperfusion rat model via calcium uptake. Hence, CLA and CLB could be potential therapeutic tools for treating cognitive dysfunction.
    Matched MeSH terms: Rats
  8. Sharma JN, Stewart JM, Mohsin SS, Katori M, Vavrek R
    Agents Actions Suppl., 1992;38 ( Pt 3):258-69.
    PMID: 1334354
    We have evaluated the effects of a B2 receptor antagonist (B5630) of kinins on BK and captopril-induced acute hypotensive responses in anaesthetized SHR. Intravenous treatment of BK (1.0 microgram) and captopril (0.3 mg/kg) caused significant (p < 0.05) fall in the SBP and DBP. Whereas BK caused greater fall in the SBP (p < 0.05), DBP (p < 0.01) and duration of hypotension (p < 0.05) when administered after captopril (Fig 1 and 2). All the hypotensive effects of BK and captopril were significantly antagonised (p < 0.05) in the presence of B5630 (2.0 mg/kg). Further, the duration of hypotensive responses of BK and captopril were blocked (p < 0.05) by B5630. The agonists and BK-antagonist did not cause significant (p > 0.05) alterations in HR during the entire investigation. These findings provide evidence to support the suggestion that B2 receptor might be involved in the regulation of the hypotensive actions of BK and captopril. Kinins should also have valuable functions in the antihypertensive property of captopril-like drugs.
    Matched MeSH terms: Rats, Inbred SHR; Rats
  9. Mohamad M, Mitchell SJ, Wu LE, White MY, Cordwell SJ, Mach J, et al.
    Aging Cell, 2016 08;15(4):706-15.
    PMID: 27095270 DOI: 10.1111/acel.12481
    While age-related insulin resistance and hyperinsulinemia are usually considered to be secondary to changes in muscle, the liver also plays a key role in whole-body insulin handling and its role in age-related changes in insulin homeostasis is largely unknown. Here, we show that patent pores called 'fenestrations' are essential for insulin transfer across the liver sinusoidal endothelium and that age-related loss of fenestrations causes an impaired insulin clearance and hyperinsulinemia, induces hepatic insulin resistance, impairs hepatic insulin signaling, and deranges glucose homeostasis. To further define the role of fenestrations in hepatic insulin signaling without any of the long-term adaptive responses that occur with aging, we induced acute defenestration using poloxamer 407 (P407), and this replicated many of the age-related changes in hepatic glucose and insulin handling. Loss of fenestrations in the liver sinusoidal endothelium is a hallmark of aging that has previously been shown to cause deficits in hepatic drug and lipoprotein metabolism and now insulin. Liver defenestration thus provides a new mechanism that potentially contributes to age-related insulin resistance.
    Matched MeSH terms: Rats, Inbred F344
  10. Kumar J, Hapidin H, Get Bee YT, Ismail Z
    Alcohol, 2016 Feb;50:9-17.
    PMID: 26626323 DOI: 10.1016/j.alcohol.2015.10.001
    Withdrawal from long-term ethanol consumption results in overexcitation of glutamatergic neurotransmission in the amygdala, which induces an anxiety-like syndrome. Most alcoholics that suffer from such symptoms frequently depend on habitual drinking as self-medication to alleviate their symptoms. Metabotropic glutamate receptor subtype 5 (mGlu5) and protein kinase C (PKC) epsilon have been reported to mediate acute and chronic effects of ethanol. This study explores the changes in mGlu5 and PKC epsilon in the amygdala following acute administration of ethanol during ethanol withdrawal (EW) induced anxiety. Male Wistar rats were fed a modified liquid diet containing low-fat cow milk, sucrose, and maltodextrin, with a gradual introduction of 2.4%, 4.8% and 7.2% ethanol for 20 days. Six hours into EW, the rats were intraperitoneally injected with normal saline and ethanol (2.5 g/kg, 20% v/v), and exposed to open-field and elevated plus maze tests. Then, amygdala tissue was dissected from the rat brain for Western blot and gene expression studies. EW-induced anxiety was accompanied by a significant increase in mGlu5, total PKC epsilon, and phosphorylated PKC epsilon protein levels, and also of mRNA of mGlu5 (GRM5) in the amygdala. Acute administration of ethanol significantly attenuated EW-induced anxiety as well as an EW-induced increase in GRM5. The acute challenge of ethanol to EW rats had little effect on the phosphorylated and total protein levels of PKC epsilon in the amygdala. Our results demonstrate that amygdala PKC epsilon may not be directly involved in the development of anxiety following EW.
    Matched MeSH terms: Rats, Wistar; Rats
  11. Coene KL, Roepman R, Doherty D, Afroze B, Kroes HY, Letteboer SJ, et al.
    Am J Hum Genet, 2009 Oct;85(4):465-81.
    PMID: 19800048 DOI: 10.1016/j.ajhg.2009.09.002
    We ascertained a multi-generation Malaysian family with Joubert syndrome (JS). The presence of asymptomatic obligate carrier females suggested an X-linked recessive inheritance pattern. Affected males presented with mental retardation accompanied by postaxial polydactyly and retinitis pigmentosa. Brain MRIs showed the presence of a "molar tooth sign," which classifies this syndrome as classic JS with retinal involvement. Linkage analysis showed linkage to Xpter-Xp22.2 and a maximum LOD score of 2.06 for marker DXS8022. Mutation analysis revealed a frameshift mutation, p.K948NfsX8, in exon 21 of OFD1. In an isolated male with JS, a second frameshift mutation, p.E923KfsX3, in the same exon was identified. OFD1 has previously been associated with oral-facial-digital type 1 (OFD1) syndrome, a male-lethal X-linked dominant condition, and with X-linked recessive Simpson-Golabi-Behmel syndrome type 2 (SGBS2). In a yeast two-hybrid screen of a retinal cDNA library, we identified OFD1 as an interacting partner of the LCA5-encoded ciliary protein lebercilin. We show that X-linked recessive mutations in OFD1 reduce, but do not eliminate, the interaction with lebercilin, whereas X-linked dominant OFD1 mutations completely abolish binding to lebercilin. In addition, recessive mutations in OFD1 did not affect the pericentriolar localization of the recombinant protein in hTERT-RPE1 cells, whereas this localization was lost for dominant mutations. These findings offer a molecular explanation for the phenotypic spectrum observed for OFD1 mutations; this spectrum now includes OFD1 syndrome, SGBS2, and JS.
    Matched MeSH terms: Rats, Wistar; Rats
  12. Newaz MA, Nawal NN, Rohaizan CH, Muslim N, Gapor A
    Am J Hypertens, 1999 Aug;12(8 Pt 1):839-44.
    PMID: 10480480
    Antioxidant protection provided by different doses of alpha-tocopherol was compared by determining nitric oxide synthase (NOS) activity in blood vessels of spontaneously hypertensive rats (SHR) treated with alpha-tocopherol. SHR were divided into four groups namely hypertensive control (C), treatment with 17 mg of alpha-tocopherol/kg diet (alpha1), 34 mg of alpha-tocopherol/kg diet (alpha2), and 170 mg of alpha-tocopherol/kg diet (alpha3). Wister Kyoto (WKY) rats were used as normal control (N). Blood pressure were recorded from the tail by physiography every other night for the duration of the study period of 3 months. At the end of the trial, animals were sacrificed. The NOS activity in blood vessels was measured by [3H]arginine radioactive assay and the nitrite concentration in plasma by spectrophotometry at wavelength 554 nm using Greiss reagent. Analysis of data was done using Student's t test and Pearson's correlation. The computer program Statistica was used for all analysis. Results of our study showed that for all the three alpha-tocopherol-treated groups, blood pressure was significantly (P < .001) reduced compared to the hypertensive control and maximum reduction of blood pressure was shown by the dosage of 34 mg of alpha-tocopherol/kg diet (C: 209.56 +/- 8.47 mm Hg; alpha2: 128.83 +/- 17.13 mm Hg). Also, NOS activity in blood vessels of SHR was significantly lower than WKY rats (N: 1.54 +/- 0.26 pmol/mg protein, C: 0.87 +/- 0.23 pmol/mg protein; P < .001). Although alpha-tocopherol in doses of alpha1, alpha2, and alpha3 increased the NOS activity in blood vessels, after treatment only that of alpha2 showed a statistical significance (P < .01). Plasma nitrite concentration was significantly reduced in SHR compared to normal WKY rats (N: 54.62 +/- 2.96 mol/mL, C: 26.24 +/- 2.14 mol/mL; P < .001) and accordingly all three groups showed significant improvement in their respective nitrite level (P < .001). For all groups, NOS activity and nitrite level showed negative correlation with blood pressure. It was significant for NOS activity in hypertensive control (r = -0.735, P = .038), alpha1 (r = -0.833, P = .001), and alpha2 (r = -0.899, P = .000) groups. For plasma nitrite, significant correlation was observed only in group alpha1 (r = -0.673, P = .016) and alpha2 (r = -0.643, P = .024). Only the alpha2 group showed significant positive correlation (r = 0.777, P = .003) between NOS activity and nitrite level. In conclusion it was found that compared to WKY rats, SHR have lower NOS activity in blood vessels, which upon treatment with antioxidant alpha-tocopherol increased the NOS activity and concomitantly reduced the blood pressure. There was correlation of lipid peroxide in blood vessels with NOS and nitric oxide, which implies that free radicals may be involved in the pathogenesis of hypertension.
    Matched MeSH terms: Rats, Inbred SHR; Rats, Inbred WKY; Rats
  13. Newaz MA, Nawal NN
    Am J Hypertens, 1998 Dec;11(12):1480-5.
    PMID: 9880131
    The aim of this study was to determine the effects of alpha-tocopherol on lipid peroxidation and total antioxidant status of spontaneously hypertensive rats (SHR), comparing them with normal Wistar-Kyoto (WKY) rats. SHR were divided into three groups and treated with different doses of alpha-tocopherol (alpha1, 17 mg/kg diet; alpha2, 34 mg/kg diet; and alpha3, 170 mg/kg diet). Normal WKY and untreated SHR were used as normal (N) and hypertensive control (HC). Blood pressures were recorded every 10 days for 3 months. At the end of the trial, animals were killed and measurement of plasma total antioxidant status, plasma superoxide dismutase (SOD) activity, and lipid peroxide levels in plasma and blood vessels was carried out following well-established methods. From our study it was found that lipid peroxides in thoracic aorta (N, 0.47 +/- 0.17; H, 0.96 +/- 0.37; P < .0001) and plasma (N, 0.06 +/- 0.01; H, 0.13 +/- 0.01) were significantly higher in hypertensives than in normal rats. SOD activity was significantly lower in hypertensive than normal rats (N, 172.93 +/- 46.91; H, 110.08 +/- 14.38; P < .005). Total antioxidant status was significantly higher in normal than hypertensive rats (N, 0.88 +/- 0.05; H, 0.83 +/- 0.02; P < .05). After the antioxidant trial, it was found that in the treated groups rise of blood pressure was prevented significantly (P < .001) and lipid peroxides in blood vessels were significantly reduced more than in the controls (P < .001). For plasma lipid peroxide it was only significant for groups alpha2 (P < .001) and alpha3 (P < .05). Although all three treated groups showed improved total antioxidant status, only groups alpha2 (0.87 +/- 0.04, P < .005) and alpha3 (1.20 +/- 0.18, P < .001) were statistically significant. All the three groups showed significant increases in their SOD activity (P < .001). Correlation studies showed that total antioxidant status and SOD were significantly negatively correlated with blood pressure in normal rats (P = .007; P = .008). Lipid peroxides in both blood vessel and plasma showed a positive correlation. In the treated groups, lipid peroxides in blood vessels maintained a significant positive correlation with blood pressure in all groups (alpha1, P = .021; alpha2, P = .019; alpha3, P = .002), whereas for plasma lipid peroxides the correlation was in groups alpha1 (P = .005) and alpha2 (P = .009). For SOD activity, significant negative correlations were found with blood pressure in the alpha2 (P = .017) and alpha3 (P = .025) groups. Total antioxidant status maintained a significant negative correlation with blood pressure in all three groups (alpha1, P = .012; alpha2, P = .044; alpha3, P = .014). In conclusion it was found that supplement of alpha-tocopherol may prevent development of increased blood pressure, reduce lipid peroxides in plasma and blood vessels, and enhance the total antioxidant status, including SOD activity.
    Matched MeSH terms: Rats, Inbred SHR; Rats, Inbred WKY; Rats
  14. Suleiman JB, Abu Bakar AB, Noor MM, Nna VU, Othman ZA, Zakaria Z, et al.
    Am J Physiol Endocrinol Metab, 2021 Sep 01;321(3):E351-E366.
    PMID: 34229480 DOI: 10.1152/ajpendo.00093.2021
    The pituitary-gonadal axis plays an important role in steroidogenesis and spermatogenesis, and by extension, fertility. The aim of this study was to investigate the protective role of bee bread, a natural bee product, against obesity-induced decreases in steroidogenesis and spermatogenesis. Thirty-two adult male Sprague-Dawley rats weighing between 200 and 300 g were divided into four groups (n = 8/group), namely: normal control (NC), high-fat diet (HFD), HFD plus bee bread administered concurrently for 12 wk (HFD + B), HFD plus orlistat administered concurrently for 12 wk (HFD + O) groups. Bee bread (0.5 g/kg) or orlistat (10 mg/kg/day) was suspended in distilled water and given by oral gavage daily for 12 wk. Levels of follicle-stimulating hormone, luteinizing hormone, testosterone, and adiponectin, as well as sperm count, motility, viability, normal morphology, and epididymal antioxidants decreased, whereas levels of leptin, malondialdehyde, and sperm nDNA fragmentation increased significantly in the HFD group relative to the NC group. There were significant decreases in the testicular mRNA transcript levels of androgen receptor, luteinizing hormone receptor, steroidogenic acute regulatory protein, cytochrome P450 enzyme, 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD in the testes of the HFD group. Furthermore, mount, intromission and ejaculatory latencies increased, and penile cGMP level decreased significantly in the HFD group. Supplementation with bee bread significantly reduced leptin level and increased adiponectin level, enhanced sperm parameters and reduced sperm nDNA fragmentation, upregulated the levels of steroidogenic genes and proteins in HFD-induced obese male rats. Bee bread improved steroidogenesis and spermatogenesis by upregulating steroidogenic genes. Therefore, bee bread may be considered as a potential supplementation to protect against infertility in overweight men or men with obesity.NEW & NOTEWORTHY The high-fat diet utilized in the present study induced obesity in the male rats. Bee bread supplementation mitigated impaired steroidogenesis, spermatogenesis, mating behavior, and fertility potential by counteracting the downregulation of steroidogenic genes, thus increasing testosterone levels and suppressing epididymal oxidative stress. These benefits may be due to the abundance of phenolic and flavonoid compounds in bee bread.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  15. Pung YF, Chilian WM, Bennett MR, Figg N, Kamarulzaman MH
    Am J Physiol Heart Circ Physiol, 2017 Mar 01;312(3):H541-H545.
    PMID: 27986661 DOI: 10.1152/ajpheart.00653.2016
    Although there are multiple rodent models of the metabolic syndrome, very few develop vascular complications. In contrast, the JCR:LA-cp rat develops both metabolic syndrome and early atherosclerosis in predisposed areas. However, the pathology of the normal vessel wall has not been described. We examined JCR:LA control (+/+) or cp/cp rats fed normal chow diet for 6 or 18 mo. JCR:LA-cp rats developed multiple features of advanced cystic medial necrosis including "cysts," increased collagen formation and proteoglycan deposition around cysts, apoptosis of vascular smooth muscle cells, and spotty medial calcification. These appearances began within 6 mo and were extensive by 18 mo. JCR:LA-cp rats had reduced medial cellularity, increased medial thickness, and vessel hypoxia that was most marked in the adventitia. In conclusion, the normal chow-fed JCR:LA-cp rat represents a novel rodent model of cystic medial necrosis, associated with multiple metabolic abnormalities, vascular smooth muscle cell apoptosis, and vessel hypoxia.NEW & NOTEWORTHY Triggers for cystic medial necrosis (CMN) have been difficult to study due to lack of animal models to recapitulate the pathologies seen in humans. Our study is the first description of CMN in the rat. Thus the JCR:LA-cp rat represents a useful model to investigate the underlying molecular changes leading to the development of CMN.
    Matched MeSH terms: Rats, Inbred Strains*; Rats
  16. Greenwood MP, Mecawi AS, Hoe SZ, Mustafa MR, Johnson KR, Al-Mahmoud GA, et al.
    Am J Physiol Regul Integr Comp Physiol, 2015 Apr 01;308(7):R559-68.
    PMID: 25632023 DOI: 10.1152/ajpregu.00444.2014
    Salt loading (SL) and water deprivation (WD) are experimental challenges that are often used to study the osmotic circuitry of the brain. Central to this circuit is the supraoptic nucleus (SON) of the hypothalamus, which is responsible for the biosynthesis of the hormones, arginine vasopressin (AVP) and oxytocin (OXT), and their transport to terminals that reside in the posterior lobe of the pituitary. On osmotic challenge evoked by a change in blood volume or osmolality, the SON undergoes a function-related plasticity that creates an environment that allows for an appropriate hormone response. Here, we have described the impact of SL and WD compared with euhydrated (EU) controls in terms of drinking and eating behavior, body weight, and recorded physiological data including circulating hormone data and plasma and urine osmolality. We have also used microarrays to profile the transcriptome of the SON following SL and remined data from the SON that describes the transcriptome response to WD. From a list of 2,783 commonly regulated transcripts, we selected 20 genes for validation by qPCR. All of the 9 genes that have already been described as expressed or regulated in the SON by osmotic stimuli were confirmed in our models. Of the 11 novel genes, 5 were successfully validated while 6 were false discoveries.
    Matched MeSH terms: Rats, Sprague-Dawley
  17. Freiria-Oliveira AH, Blanch GT, Pedrino GR, Cravo SL, Murphy D, Menani JV, et al.
    Am J Physiol Regul Integr Comp Physiol, 2015 Nov 01;309(9):R1082-91.
    PMID: 26333788 DOI: 10.1152/ajpregu.00432.2014
    Noradrenergic A2 neurons of the nucleus of the solitary tract (NTS) have been suggested to contribute to body fluid homeostasis and cardiovascular regulation. In the present study, we investigated the effects of lesions of A2 neurons of the commissural NTS (cNTS) on the c-Fos expression in neurons of the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, arterial pressure, water intake, and urinary excretion in rats with plasma hyperosmolality produced by intragastric 2 M NaCl (2 ml/rat). Male Holtzman rats (280-320 g) received an injection of anti-dopamine-β-hydroxylase-saporin (12.6 ng/60 nl; cNTS/A2-lesion, n = 28) or immunoglobulin G (IgG)-saporin (12.6 ng/60 nl; sham, n = 24) into the cNTS. The cNTS/A2 lesions increased the number of neurons expressing c-Fos in the magnocellular PVN in rats treated with hypertonic NaCl (90 ± 13, vs. sham: 47 ± 20; n = 4), without changing the number of neurons expressing c-Fos in the parvocellular PVN or in the SON. Contrary to sham rats, intragastric 2 M NaCl also increased arterial pressure in cNTS/A2-lesioned rats (16 ± 3, vs. sham: 2 ± 2 mmHg 60 min after the intragastric load; n = 9), an effect blocked by the pretreatment with the vasopressin antagonist Manning compound (0 ± 3 mmHg; n = 10). In addition, cNTS/A2 lesions enhanced hyperosmolality-induced water intake (10.5 ± 1.4, vs. sham: 7.7 ± 0.8 ml/60 min; n = 8-10), without changing renal responses to hyperosmolality. The results suggest that inhibitory mechanisms dependent on cNTS/A2 neurons reduce water intake and vasopressin-dependent pressor response to an acute increase in plasma osmolality.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  18. Hong YH, Betik AC, Premilovac D, Dwyer RM, Keske MA, Rattigan S, et al.
    Am J Physiol Regul Integr Comp Physiol, 2015 May 15;308(10):R862-71.
    PMID: 25786487 DOI: 10.1152/ajpregu.00412.2014
    Nitric oxide (NO) has been shown to be involved in skeletal muscle glucose uptake during contraction/exercise, especially in individuals with Type 2 diabetes (T2D). To examine the potential mechanisms, we examined the effect of local NO synthase (NOS) inhibition on muscle glucose uptake and muscle capillary blood flow during contraction in healthy and T2D rats. T2D was induced in Sprague-Dawley rats using a combined high-fat diet (23% fat wt/wt for 4 wk) and low-dose streptozotocin injections (35 mg/kg). Anesthetized animals had one hindlimb stimulated to contract in situ for 30 min (2 Hz, 0.1 ms, 35 V) with the contralateral hindlimb rested. After 10 min, the NOS inhibitor, N(G)-nitro-l-arginine methyl ester (l-NAME; 5 μM) or saline was continuously infused into the femoral artery of the contracting hindlimb until the end of contraction. Surprisingly, there was no increase in skeletal muscle NOS activity during contraction in either group. Local NOS inhibition had no effect on systemic blood pressure or muscle contraction force, but it did cause a significant attenuation of the increase in femoral artery blood flow in control and T2D rats. However, NOS inhibition did not attenuate the increase in muscle capillary recruitment during contraction in these rats. Muscle glucose uptake during contraction was significantly higher in T2D rats compared with controls but, unlike our previous findings in hooded Wistar rats, NOS inhibition had no effect on glucose uptake during contraction. In conclusion, NOS inhibition did not affect muscle glucose uptake during contraction in control or T2D Sprague-Dawley rats, and this may have been because there was no increase in NOS activity during contraction.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  19. Mohd Zain Z, Ab Ghani S, O'Neill RD
    Amino Acids, 2012 Nov;43(5):1887-94.
    PMID: 22865247 DOI: 10.1007/s00726-012-1365-0
    This paper discusses the application of a reagentless, selective microbiosensor as a useful alternative tool for monitoring D-serine in neural samples. The main components of the 125-μm-diameter disk biosensor were D-amino acid oxidase for D-serine sensitivity (linear region slope, 61 ± 7 μA cm(-2) mM(-1); limit of detection, 20 nM), and poly-phenylenediamine for rejection of electroactive interference. The response time of the biosensor was of the order of 1 s, ideal for 'real-time' monitoring, and detection of systemically administered D-serine in brain extracellular fluid is demonstrated. Exploitation of this probe might resolve queries involving regulation of D-serine in excitotoxicity, and modulation of N-methyl-D-aspartate receptor function by D-serine and glycine in the central nervous system.
    Matched MeSH terms: Rats
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