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Fulltext Toxicity assessment of gallic acid loaded graphene oxide (GAGO) nano-formulation in zebrafish (Danio Rerio) embryos

Ahmad Ashraful Hadi Abdul Ghafor, Nurhuda Elias, Suhaili Shams, Faizah Md Yasin, Sarchio, Seri Narti Edayu

Pertanika Journal of Science & Technology, 2020;28(1):311-326.
MyJurnal

Gallic acid (GA) is a phenolic compound found in almost all plants and has been reported to possess powerful health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, and anti-diabetic properties. However, GA suffers a short half-life when administered in vivo. Recent studies have employed graphene oxide (GO), a biocompatible and cost-effective graphene derivative, as a nanocarrier for GA. However, the toxicity effect of this formulated nano-compound has not been fully studied. Thus, the present study aims to evaluate the toxicity and teratogenicity of GA loaded GO (GAGO) against zebrafish embryogenesis to further advance the development of GA as a therapeutic agent. GAGO was exposed to zebrafish embryos (n ≥ 10; 24hr post fertilization (hpf)) at different concentrations (0-500 μg/ml). The development of zebrafish was observed and recorded twice daily for four days. The toxicity of pure GO and GA was also observed at similar concentrations. Distilled water was used as control throughout the experiment. A significantly high mortality rate, delayed hatching rate and low heartbeat were recorded in embryos exposed to GO at concentrations of ≥ 150 μg/ml at 48 hr (p

Matched MeSH terms: Heart Rate
Fulltext A systematic review of automated pre-processing, feature extraction and classification of cardiotocography

Al-Yousif S, Jaenul A, Al-Dayyeni W, Alamoodi A, Jabori I, Md Tahir N, et al.

PeerJ Comput Sci, 2021;7:e452.
PMID: 33987454 DOI: 10.7717/peerj-cs.452

Context: The interpretations of cardiotocography (CTG) tracings are indeed vital to monitor fetal well-being both during pregnancy and childbirth. Currently, many studies are focusing on feature extraction and CTG classification using computer vision approach in determining the most accurate diagnosis as well as monitoring the fetal well-being during pregnancy. Additionally, a fetal monitoring system would be able to perform detection and precise quantification of fetal heart rate patterns.
Objective: This study aimed to perform a systematic review to describe the achievements made by the researchers, summarizing findings that have been found by previous researchers in feature extraction and CTG classification, to determine criteria and evaluation methods to the taxonomies of the proposed literature in the CTG field and to distinguish aspects from relevant research in the field of CTG.
Methods: Article search was done systematically using three databases: IEEE Xplore digital library, Science Direct, and Web of Science over a period of 5 years. The literature in the medical sciences and engineering was included in the search selection to provide a broader understanding for researchers.
Results: After screening 372 articles, and based on our protocol of exclusion and inclusion criteria, for the final set of articles, 50 articles were obtained. The research literature taxonomy was divided into four stages. The first stage discussed the proposed method which presented steps and algorithms in the pre-processing stage, feature extraction and classification as well as their use in CTG (20/50 papers). The second stage included the development of a system specifically on automatic feature extraction and CTG classification (7/50 papers). The third stage consisted of reviews and survey articles on automatic feature extraction and CTG classification (3/50 papers). The last stage discussed evaluation and comparative studies to determine the best method for extracting and classifying features with comparisons based on a set of criteria (20/50 articles).
Discussion: This study focused more on literature compared to techniques or methods. Also, this study conducts research and identification of various types of datasets used in surveys from publicly available, private, and commercial datasets. To analyze the results, researchers evaluated independent datasets using different techniques.
Conclusions: This systematic review contributes to understand and have insight into the relevant research in the field of CTG by surveying and classifying pertinent research efforts. This review will help to address the current research opportunities, problems and challenges, motivations, recommendations related to feature extraction and CTG classification, as well as the measurement of various performance and various data sets used by other researchers.

Matched MeSH terms: Heart Rate, Fetal
Development of a new computer-based physical activity questionnaire to estimate habitual physical activity level in Malaysian adolescents

Teo PS, Nurul-Fadhilah A, Foo LH

J Sci Med Sport, 2013 Jul;16(4):327-31.
PMID: 22858164 DOI: 10.1016/j.jsams.2012.06.012

To assess the validity and reproducibility of a new computer-based physical activity questionnaire (cPAQ) to estimate the habitual physical activity levels in Malaysian adolescents.

Matched MeSH terms: Heart Rate
Gross mismatch between thermal tolerances and environmental temperatures in a tropical freshwater snail: climate warming and evolutionary implications

Polgar G, Khang TF, Chua T, Marshall DJ

J Therm Biol, 2015 Jan;47:99-108.
PMID: 25526660 DOI: 10.1016/j.jtherbio.2014.11.009

The relationship between acute thermal tolerance and habitat temperature in ectotherm animals informs about their thermal adaptation and is used to assess thermal safety margins and sensitivity to climate warming. We studied this relationship in an equatorial freshwater snail (Clea nigricans), belonging to a predominantly marine gastropod lineage (Neogastropoda, Buccinidae). We found that tolerance of heating and cooling exceeded average daily maximum and minimum temperatures, by roughly 20°C in each case. Because habitat temperature is generally assumed to be the main selective factor acting on the fundamental thermal niche, the discordance between thermal tolerance and environmental temperature implies trait conservation following 'in situ' environmental change, or following novel colonisation of a thermally less-variable habitat. Whereas heat tolerance could relate to an historical association with the thermally variable and extreme marine intertidal fringe zone, cold tolerance could associate with either an ancestral life at higher latitudes, or represent adaptation to cooler, higher-altitudinal, tropical lotic systems. The broad upper thermal safety margin (difference between heat tolerance and maximum environmental temperature) observed in this snail is grossly incompatible with the very narrow safety margins typically found in most terrestrial tropical ectotherms (insects and lizards), and hence with the emerging prediction that tropical ectotherms, are especially vulnerable to environmental warming. A more comprehensive understanding of climatic vulnerability of animal ectotherms thus requires greater consideration of taxonomic diversity, ecological transition and evolutionary history.

Matched MeSH terms: Heart Rate
Fulltext Effects of Swedish massage therapy on blood pressure, heart rate, and inflammatory markers in hypertensive women

Supa'at I, Zakaria Z, Maskon O, Aminuddin A, Nordin NA

Evid Based Complement Alternat Med, 2013;2013:171852.
PMID: 24023571 DOI: 10.1155/2013/171852

Swedish Massage Therapy (SMT) is known for its therapeutic relaxation effects. Hypertension is associated with stress and elevated endothelial inflammatory markers. This randomized control trial measured the effects of whole body SMT (massage group) or resting (control group) an hour weekly for four weeks on hypertensive women. Blood pressure (BP) and heart rate (HR) were measured before and after each intervention and endothelial inflammatory markers: vascular endothelial adhesion molecules 1 (VCAM-1) and intracellular adhesion molecules 1 (ICAM-1) were measured at baseline and after the last intervention. Massage group (n=8) showed significant systolic BP (SBP) reduction of 12 mmHg (P=0.01) and diastolic BP (DBP) reduction of 5 mmHg (P=0.01) after four sessions with no significant difference between groups. Reductions in HR were also seen in massage group after sessions 1, 3, and 4 with significant difference between groups. VCAM-1 showed significant reduction after four sessions: the massage group showed reduction of 998.05 ng/mL (P=0.03) and the control group of 375.70 ng/mL (P=0.01) with no significant differences between groups. There were no changes in ICAM-1. In conclusion, SMT or resting an hour weekly has effects on reducing BP, HR, and VCAM-1 in hypertensive women.

Matched MeSH terms: Heart Rate
Fulltext Effect of Short-Term Mobile Phone Base Station Exposure on Cognitive Performance, Body Temperature, Heart Rate and Blood Pressure of Malaysians

Malek F, Rani KA, Rahim HA, Omar MH

Sci Rep, 2015;5:13206.
PMID: 26286015 DOI: 10.1038/srep13206

Individuals who report their sensitivity to electromagnetic fields often undergo cognitive impairments that they believe are due to the exposure of mobile phone technology. The aim of this study is to clarify whether short-term exposure at 1 V/m to the typical Global System for Mobile Communication and Universal Mobile Telecommunications System (UMTS) affects cognitive performance and physiological parameters (body temperature, blood pressure and heart rate). This study applies counterbalanced randomizing single blind tests to determine if sensitive individuals experience more negative health effects when they are exposed to base station signals compared with sham (control) individuals. The sample size is 200 subjects with 50.0% Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF) also known as sensitive and 50.0% (non-IEI-EMF). The computer-administered Cambridge Neuropsychological Test Automated Battery (CANTAB eclipse(TM)) is used to examine cognitive performance. Four tests are chosen to evaluate Cognitive performance in CANTAB: Reaction Time (RTI), Rapid Visual Processing (RVP), Paired Associates Learning (PAL) and Spatial Span (SSP). Paired sample t-test on the other hand, is used to examine the physiological parameters. Generally, in both groups, there is no statistical significant difference between the exposure and sham exposure towards cognitive performance and physiological effects (P's > 0.05).

Matched MeSH terms: Heart Rate
Fulltext Standing beat-to-beat blood pressure variability is reduced among fallers in the Malaysian Elders Longitudinal Study

Goh CH, Ng SC, Kamaruzzaman SB, Chin AV, Tan MP

Medicine (Baltimore), 2017 Oct;96(42):e8193.
PMID: 29049203 DOI: 10.1097/MD.0000000000008193

The aim of this study was to determine the relationship between falls and beat-to-beat blood pressure (BP) variability.Continuous noninvasive BP measurement is as accurate as invasive techniques. We evaluated beat-to-beat supine and standing BP variability (BPV) using time and frequency domain analysis from noninvasive continuous BP recordings.A total of 1218 older adults were selected. Continuous BP recordings obtained were analyzed to determine standard deviation (SD) and root mean square of real variability (RMSRV) for time domain BPV and fast-Fourier transform low frequency (LF), high frequency (HF), total power spectral density (PSD), and LF:HF ratio for frequency domain BPV.Comparisons were performed between 256 (21%) individuals with at least 1 fall in the past 12 months and nonfallers. Fallers were significantly older (P = .007), more likely to be female (P = .006), and required a longer time to complete the Timed-Up and Go test (TUG) and frailty walk test (P ≤ .001). Standing systolic BPV (SBPV) was significantly lower in fallers compared to nonfallers (SBPV-SD, P = .016; SBPV-RMSRV, P = .033; SBPV-LF, P = .003; SBPV-total PSD, P = .012). Nonfallers had significantly higher supine to standing ratio (SSR) for SBPV-SD, SBPV-RMSRV, and SBPV-total PSD (P = .017, P = .013, and P = .009). In multivariate analyses, standing BPV remained significantly lower in fallers compared to nonfallers after adjustment for age, sex, diabetes, frailty walk, and supine systolic BP. The reduction in frequency-domain SSR among fallers was attenuated by supine systolic BP, TUG, and frailty walk.In conclusion, reduced beat-to-beat BPV while standing is independently associated with increased risk of falls. Changes between supine and standing BPV are confounded by supine BP and walking speed.

Matched MeSH terms: Heart Rate/physiology
Fulltext Chemical immobilization of free-ranging and captive Sunda clouded leopards (Neofelis diardi) with two anesthetic protocols: medetomidine-ketamine and tiletamine-zolazepam

Nájera F, Hearn AJ, Ross J, Ramírez Saldivar DA, Evans MN, Guerrero-Sánchez S, et al.

J Vet Med Sci, 2017 Nov 17;79(11):1892-1898.
PMID: 28904261 DOI: 10.1292/jvms.17-0259

There is currently no available information regarding the veterinary management of Sunda clouded leopards (Neofelis diardi), either in captivity or in the wild. In this study, 12 Sunda clouded leopards were anesthetized between January 2008 and February 2014 for medical exams, and/or GPS-collaring. Seven wild-caught individuals were kept in captivity and 5 free-ranging animals were captured by cage traps. Two anesthesia combinations were used: medetomidine-ketamine (M-K) or tiletamine-zolazepam (T-Z). Atipamezole (0.2 mg/kg im) was used as an antagonist for medetomidine. Medetomidine (range: 0.039-0.054 mg/kg) and ketamine (range: 3-4.39 mg/kg) were administered during 5 immobilizations, resulting in median induction times of 7 min. After a median anesthesia time of 56 min, atipamezole was injected, observing effects of antagonism at a median time of 12 min. T-Z (range: 6.8-10.8 mg/kg) was administered on 7 occasions. Median induction times observed with this combination were shorter than with M-K (4 min vs 7 min; P=0.04), and anesthesia and recovery times were significantly longer (244 and 35 min vs 56 and 16 min, respectively; P=0.02). Lower heart rates were measured in the M-K group, while lower rectal temperatures were found in the T-Z group. Both combinations resulted in safe and reliable immobilizations, although given the favorable anesthesia and recovery times of M-K, we recommend this approach over T-Z for the veterinary handling of Sunda clouded leopards.

Matched MeSH terms: Heart Rate/drug effects
Fulltext Evoked K-complexes and altered interaction between the central and autonomic nervous systems during sleep in alcohol use disorder

Willoughby AR, de Zambotti M, Baker FC, Colrain IM

Alcohol, 2020 May;84:1-7.
PMID: 31539623 DOI: 10.1016/j.alcohol.2019.09.005

There is evidence for impairment in both central nervous system (CNS) and autonomic nervous system (ANS) function with prolonged alcohol use. While these impairments persist into abstinence, partial recovery of function has been demonstrated in both systems during sleep. To investigate potential ANS dysfunction associated with cortical CNS responses (impairment in CNS-ANS coupling), we assessed phasic heart rate (HR) fluctuation associated with tones that did and those that did not elicit a K-complex (KC) during stable N2 non-rapid eye movement (NREM) sleep in a group of 16 recently abstinent alcohol use disorder (AUD) patients (41.6 ± 8.5 years) and a group of 13 sex- and age-matched control participants (46.6 ± 9.3 years). Electroencephalogram (EEG) and electrocardiogram (ECG) data were recorded throughout the night. Alcohol consumption questionnaires were also administered to the AUD patients. AUD patients had elevated HR compared to controls at baseline prior to tone presentation. The HR fluctuation associated with KCs elicited by tone presentation was significantly smaller in amplitude, and tended to be delayed in time, in the AUD group compared with the control group, and the subsequent deceleration was also smaller in AUD patients. In both groups, the increase in HR was larger and occurred earlier when KCs were produced than when they were not, and there was no difference in the magnitude of the KC effect between groups. Phasic HR changes associated with KCs elicited by tones are impaired in AUD participants, reflecting ANS dysfunction possibly caused by an alteration of cardiac vagal trafficking. However, only the timing of the HR response was found to relate to estimated lifetime alcohol consumption in AUD. The clinical meaning and implications of these novel findings need to be determined.

Matched MeSH terms: Heart Rate*
Evaluation of anaesthetic and cardiorespiratory effects after intramuscular administration of alfaxalone alone, alfaxalone-ketamine and alfaxalone-butorphanol-medetomidine in common marmosets (Callithrix jacchus)

Miyabe-Nishiwaki T, Miwa M, Konoike N, Kaneko A, Ishigami A, Natsume T, et al.

J Med Primatol, 2020 12;49(6):291-299.
PMID: 32654222 DOI: 10.1111/jmp.12482

BACKGROUND: Anaesthesia is often required in common marmosets undergoing various procedures. The aim of this study was to evaluate anaesthetic and cardiopulmonary effects of alfaxalone, alfaxalone-ketamine and alfaxalone-butorphanol-medetomidine in common marmosets.
METHODS: The following treatments were repeatedly administered to seven female common marmosets: Treatment A, alfaxalone (12 mg kg-1 ) alone; treatment AK, alfaxalone (1 mg animal-1 ) plus ketamine (2.5 mg animal-1 ); treatment AMB, alfaxalone (4 mg kg-1 ), medetomidine (50 µg kg-1 ) plus butorphanol (0.3 mg kg-1 ); and treatment AMB-Ati, AMB with atipamezole at 45 minutes.
RESULTS AND CONCLUSIONS: Marmosets became laterally recumbent and unresponsive for approximately 30 minutes in A and AK and for approximately 60 minutes in AMB. The animals showed rapid recovery following atipamezole injection in AMB-Ati. The decrease in heart rate and SpO2 was significantly greater in AMB compared to A and AK. Oxygen supplementation, anaesthetic monitors and atipamezole should be available especially when AMB is administered.

Matched MeSH terms: Heart Rate/drug effects
Fulltext Fetal supraventricular tachycardia--a case report

Soh EBS, Raman S, Chia PMK

Med J Malaysia, 1998 Sep;53(3):280-3.
PMID: 10968167

A gravid patient with fetal supraventricular tachycardia is presented. A review of this rare condition and the present recommended mode of therapy are discussed.

Matched MeSH terms: Heart Rate/drug effects
Cardiovascular effects of aspidofractinine-type alkaloids from Kopsia

Mok SL, Yoganathan K, Lim TM, Kam TS

J Nat Prod, 1998 Mar;61(3):328-32.
PMID: 9544563

Intravenous injection of the aspidofractinine alkaloid, kopsingine (1, 0.2-10.0 mg/kg) from Kopsia teoi, produced dose-related decreases in the mean arterial blood pressure and heart rate in anesthetized spontaneously hypertensive rats, which were similar to those seen in normotensive controls. Minor modifications in the molecular structure of kopsingine, as in kopsaporine (2, the 12-demethoxy derivative of kopsingine) and 14,15-dihydrokopsingine (4), did not significantly alter the hypotensive responses, whereas a more drastic change in the structure, as in the heptacyclic kopsidine A (3) and the 3-to-17 oxo-bridged compound 5, resulted in an increase in blood pressure. The antihypertensive effects of kopsingine (1) and its congeners (2 and 4) along with the pressor effects produced by the heptacyclic oxo-bridged compounds (5 and 3) could be ascribed to central as well as peripheral actions.

Matched MeSH terms: Heart Rate/drug effects
Suppression of hypotensive responses of captopril and enalapril by the kallikrein inhibitor aprotinin in spontaneously hypertensive rats

Sharma JN, Amrah SS, Noor AR

Pharmacology, 1995 Jun;50(6):363-9.
PMID: 7568335

The present investigation evaluated the effects of aprotinin, an inhibitor of kallikrein, on blood pressure responses, heart rate, and duration of hypotension induced by acute administration of captopril and enalapril (angiotensin-converting enzyme inhibitors) in anaesthetized spontaneously hypertensive rats. Captopril (20 mg/kg) and enalapril (20 mg/kg) administered intravenously caused a significant (p < 0.001) fall in systolic and diastolic blood pressures in the absence of aprotinin. In contrast, captopril (20 mg/kg) and enalapril (20 mg/kg) failed (p > 0.05) to cause a fall in systolic and diastolic blood pressures in the presence of aprotinin (2 mg/kg). Captopril and enalapril were able to significantly reduce the heart rate (p < 0.05 and p < 0.001) in the presence as well as in the absence of aprotinin. The duration of hypotension produced by captopril and enalapril was abolished significantly (p < 0.001) in the presence of aprotinin. These findings may suggest that captopril and enalapril caused hypotension via the kallikrein pathway, since the kallikrein inhibitor aprotinin can antagonize the hypotensive responses of these agents. Thus, kallikrein may be an independent mediator in the regulation of blood pressure.

Matched MeSH terms: Heart Rate/drug effects
Differential Effects of 7 and 16 Groups of Muscle Relaxation Training Following Repeated Submaximal Intensity Exercise in Young Football Players

Sharifah Maimunah SM, Hashim HA

Percept Mot Skills, 2016 Feb;122(1):227-37.
PMID: 27420318 DOI: 10.1177/0031512515625383

This study compares two versions of progressive muscle relaxation (PMR) training (7 and 16 muscle groups) on oxygen consumption (VO2), heart rates, rating of perceived exertion and choice reaction time. Football (soccer) players (N = 26; M age = 13.4 yr., SD = 0.5) were randomly assigned to either 7 muscle groups PMR, 16 muscle groups PMR, or a control group. PMR training requires the participants to tense a muscle, hold the muscle contraction, and then relax it. Measurement was conducted prior to and after the completion of 12 sessions of PMR. The dependent variables were measured following four bouts of intermittent exercise consisting of 12 min. of running at 60% VO2max for 10 min. followed by running at 90% VO2max for 2 min. with a 3-min. rest for each bout. Lower VO2, heart rate, perceived exertion, and quicker reaction time were expected in both relaxation groups compared to the control group. The results revealed a significant reduction in heart rates and choice reaction time for both relaxation groups, but the longer version produced significantly quicker choice reaction time.

Matched MeSH terms: Heart Rate/physiology*
Fulltext Dose requirement and effect of nicardipine on lipid profile in mild to moderate essential hypertensives

Tariq AR, Maheendran K, Kamsiah J, Christina P

Med J Malaysia, 1992 Sep;47(3):182-9.
PMID: 1491643

Twenty eight patients who satisfied the entry criteria and had completed an initial 2 weeks treatment with placebo were titrated fortnightly with doses of Nicardipine ranging from 30 mg to 90 mg daily in two or three divided doses. Nicardipine treatment significantly reduced blood pressures both in the supine and standing positions (p < 0.0004) when compared with placebo treatment. Heart rates however did not change significantly. Forty six percent (13/28) of patients on 20 mg twice daily, 25% (7/28) on 10 mg three times daily, 18% (5/28) of patients on 20 mg three times daily and 11% (3/28) on 30 mg three times daily achieved supine diastolic blood pressures < 90 mm Hg. Nicardipine treatment at 16 weeks and at 24 weeks did not significantly alter the lipid profile when compared to the end of placebo treatment period. No other biochemical abnormalities were reported during the study period. Except for 2 cases of mild pedal oedema and 2 cases of transient headaches, no serious side-effects were encountered.

Matched MeSH terms: Heart Rate/drug effects
Fulltext Once daily felodipine monotherapy in mild to moderate hypertension

Kon SP, Tan HW, Chua CT, Ong ML, Kamsiah J, Maheendran KK, et al.

Med J Malaysia, 1992 Dec;47(4):290-6.
PMID: 1303482

In a single-blind study conducted at our centres, 78 hypertensive patients were enrolled with 58 completing the study according to the protocol. Mean supine and standing blood pressures were significantly reduced after treatment with felodipine, reductions being 27/21 mmHg (p < 0.0001) and 25/19 mmHg (p < 0.0001) respectively. Of 46 patients given felodipine 5 mg, 44 (95.7%) achieved target blood pressure defined as a diastolic blood pressure of < 90 mmHg, while all 12 patients on felodipine 10 mg did so. The 2 patients who did not achieve target pressure at the final visit did so on previous visits. There were no differences in pre and post-treatment laboratory variables. Treatment was discontinued in 6 patients because of headaches. No adverse events of clinical significance were reported in the 58 patients who completed the study. In conclusion, we found felodipine given once daily to be effective in the treatment of mild to moderate hypertension.

Study site: Multicentre

Matched MeSH terms: Heart Rate/drug effects
Cardiovascular responses in the normotensive rat produced by intravenous injection of gambirine isolated from Uncaria callophylla B1. ex Korth

Mok JS, Chang P, Lee KH, Kam TS, Goh SH

J Ethnopharmacol, 1992 Jun;36(3):219-23.
PMID: 1434680

Among several alkaloids, including dimeric indoles, isolated from Uncaria callophylla, gambirine which is an alkaloid unique to this plant, has been found to be another hypotensive principle from the plant. Intravenous injections of gambirine in the dose range of 0.2 to 10.0 mg/kg caused a dose-related fall in both systolic and diastolic blood pressures as well as heart rate. At all doses gambirine showed a prompt onset of action and at the higher doses (5.0-10 mg/kg), marked persistence of hypotension accompanied by severe bradycardia were observed. In addition, higher doses of gambirine produced a more marked decrease in diastolic than systolic pressure while at lower doses both decreased equally. It is suggested that the hypotensive effect of gambirine may be peripheral in origin and is associated, at least in part, with a cardiac action.

Matched MeSH terms: Heart Rate/drug effects*
Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Hypertensive Effect of Protein Hydrolysate from Actinopyga lecanora (Sea Cucumber) in Rats

Sadegh Vishkaei M, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N

Mar Drugs, 2016 Sep 30;14(10).
PMID: 27706040

Food protein hydrolysates are known to exhibit angiotensin converting enzyme (ACE) inhibitory properties and can be used as a novel functional food for prevention of hypertension. This study evaluated the ACE inhibitory potentials of Actinopyga lecanora proteolysate (ALP) in vivo. The pre-fed rats with ALP at various doses (200, 400, 800 mg/kg body weight) exhibited a significant (p ≤ 0.05) suppression effect after inducing hypertension. To determine the optimum effective dose that will produce maximal reduction in blood pressure, ALP at three doses was fed to the rats after inducing hypertension. The results showed that the 800 mg/kg body weight dose significantly reduced blood pressure without noticeable negative physiological effect. In addition, there were no observable changes in the rats' heart rate after oral administration of the ALP. It was concluded that Actinopyga lecanora proteolysate could potentially be used for the development of functional foods and nutraceuticals for prevention and treatment of hypertension.

Matched MeSH terms: Heart Rate/drug effects
Hemodynamic effects of HPMA copolymer based doxorubicin conjugate: A randomized controlled and comparative spectral study in conscious rats

Cheah HY, Šarenac O, Arroyo JJ, Vasić M, Lozić M, Glumac S, et al.

Nanotoxicology, 2017 03;11(2):210-222.
PMID: 28098511 DOI: 10.1080/17435390.2017.1285071

Conjugation of Doxorubicin (DOX) to N-(2-hydroxypropyl) methylacrylamide copolymer (HPMA) has significantly reduced the DOX-associated cardiotoxicity. However, the reports on the impact of HPMA-DOX conjugates on the cardiovascular system such as blood pressure (BP) and heart rate (HR) were in restrained animals using tail cuff and/or other methods that lacked the resolution and sensitivity. Herein, we employed radiotelemetric-spectral-echocardiography approach to further understand the in vivo cardiovascular hemodynamics and variability post administration of free DOX and HPMA-DOX. Rats implanted with radio-telemetry device were administered intravenously with DOX (5 mg/kg), HPMA-DOX (5 mg DOX equivalent/kg) and HPMA copolymer and subjected to continuous cardiovascular monitoring and echocardiography for 140 days. We found that DOX-treated rats had ruffled fur, reduced body weight (BW) and a low survival rate. Although BP and HR were normal, spectral analysis indicated that their BP and HR variabilities were reduced. All rats exhibited typical signs of cardiotoxicity at histopathology. In contrast, HPMA-DOX rats gained weight over time and survived. Although BP, HR and related variabilities were unaffected, the left ventricular end diastolic volume (EDV) of these rats, as well as of the HPMA copolymer-treated rats, was found increased at the end of observation period. Additionally, HPMA copolymer caused microscopic injury of the heart tissue. All of these suggest the necessity of caution when employing HPMA as carrier for prolonged drug delivery. The current study also indicates the potential of radiotelemetric-spectral-echocardiography approach for improved preclinical cardiovascular risk assessment of polymer-drug conjugate and other nano-sized-drug constructs.

Matched MeSH terms: Heart Rate/drug effects*
Effect of bradykinin and its antagonist on survival time after coronary artery occlusion in rats

Atif Abbas S, Sharma JN, Pauzi A, Yusof M

Gen. Pharmacol., 1999 Sep;33(3):243-7.
PMID: 10480657

The present study was conducted to examine the effect of bradykinin and bradykinin 2 receptor antagonist on survival time in rats with coronary artery ligation for 15 min and continuously. We also evaluated the heart rate and blood pressure responses in the presence and absence of bradykinin and its antagonist. Bradykinin treatment (4 microg and 8 microg/kg IV) significantly (p < 0.05) increased the survival time of rats compared with saline-treated rats with coronary artery ligation for 15 min and continuously. The heart rate and blood pressure responses were significantly (p < 0.001) altered in the presence of coronary artery ligation. Bradykinin antagonist treatment (4 microg/kg IV) abolished the effect of bradykinin and thus reduced the survival time of rats with coronary artery ligation. The mean value of survival time between saline-treated and bradykinin antagonist- plus bradykinin-treated rats did not differ significantly (p > 0.05).

Matched MeSH terms: Heart Rate/drug effects

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