Whole-Body Vibration Training Increases Myocardial Salvage Against Acute Ischemia in Adult Male Rats / Treinamento de Vibração de Corpo Inteiro Aumenta o Resgate Miocárdico contra Isquemia Aguda em Ratos Machos Adultos

Abstract Background: Whole body vibration training (WBV) is a new training program, which is safe and effective. It can be followed by the public. However, data on the safety and efficacy of vibration on myocardial ischemia reperfusion (IR) injury are lacking. Objective: To examine the effect of WBV on the tolerance of the myocardium to acute IR injury in an experimental rat model. Methods: Twenty-four male Wistar rats were divided into control and vibration groups. Vibration training consisted of vertical sinusoidal whole body vibration for 30 min per day, 6 days per week, for 1 or 3 weeks (WBV1 and WBV3 groups, respectively). All the rats were submitted to myocardial IR injury. Myocardial infarct size and ischemia-induced arrhythmias were assessed. Differences between variables were considered significant when p < 0.05. Results: No differences were observed between the groups regarding the baseline hemodynamic parameters. Infarct size was smaller in the experimental group (control, 47 ± 2%; WBV1, 39 ± 2%; WBV3, 37 ± 2%; p < 0.05, vs. control). Vibration produced a significant decrease in the number and duration of ventricular tachycardia (VT) episodes compared to the control value. All ventricular fibrillation (VF) episodes in the vibration groups were self-limited, while 33% of the rats in the control group died due to irreversible VF (p = 0.02). Conclusion: The data showed that vibration training significantly increased cardiac tolerance to IR injury in rats, as evidenced by reduction in the infarct size and cardiac arrhythmias, and by facilitating spontaneous defibrillation.

Resumo Fundamento: O treinamento com vibração de corpo inteiro (WBV) é um novo programa de treinamento seguro e eficaz, e pode ser seguido pelo público. No entanto, dados sobre a segurança e eficácia da vibração na lesão de isquemia e reperfusão (IR) do miocárdio estão em falta. Objetivo: Examinar o efeito da WBV na tolerância do miocárdio à lesão aguda por IR em um modelo experimental em ratos. Métodos: Vinte e quatro ratos Wistar machos foram divididos em 2 grupos: controle e vibração. O treino de vibração consistiu em vibração sinusoidal vertical de corpo inteiro durante 30 min por dia, 6 dias por semana, durante 1 ou 3 semanas (grupos WBV1 e WBV3, respectivamente). Todos os ratos foram submetidos a lesão por IR do miocárdio. O tamanho do infarto do miocárdio e as arritmias induzidas por isquemia foram avaliados. As diferenças entre as variáveis foram consideradas significativas quando p < 0,05. Resultados: Não foram observadas diferenças entre os grupos em relação aos parâmetros hemodinâmicos basais. O tamanho do infarto foi menor no grupo experimental (controle, 47 ± 2%; WBV1, 39 ± 2%; WBV3, 37 ± 2%; p < 0,05, vs. controle). A vibração produziu uma diminuição significativa no número e duração das taquicardia ventriculares (TV) em comparação com o valor de controle. Todos os episódios de fibrilação ventricular (FV) nos grupos de vibração foram autolimitados, enquanto 33% dos ratos do grupo controle morreram devido a FV irreversível (p = 0,02). Conclusão: Os dados mostraram que o treinamento com vibração de corpo inteiro aumentou significativamente a tolerância cardíaca à lesão de IR em ratos, como evidenciado pela redução do tamanho do infarto e arritmias cardíacas, e pela facilitação da desfibrilação espontânea.

Alteration at transcriptional level of cardiac renin-angiotensin system by letrozole treatment.

INTRODUCTION: The use of aromatase inhibitors (AIs) for breast cancer led to a marked change in ventricular function. Since accumulating evidence indicates that overactivation of the cardiac renin-angiotensin system (RAS) plays an important role in the development of cardiovascular diseases such as hypertrophy and remodelling, we aimed to investigate whether letrozole alters the transcription level of RAS related genes in the cardiac tissue. METHODS: Twenty four rats were randomly divided into four groups (n = 6 per group): two groups were letrozole treated (1 and 2 mg/kg/day orally), one group was vehicle treated (DMSO) and one group was the control group without any treatment. 12 weeks after beginning treatment with letrozole, we examined the rate of transcription of renin, angiotensinogen, AngII type 1a and 1b (AT1a and AT1b) and type 2 receptors (AT2) in the rat heart using real-time polymerase chain reaction. RESULTS: The cardiac mRNA levels of several components of the RAS in the rats treated with letrozole were significantly increased including AT1a receptor (80%), renin (51%), and angiotensinogen (33%). Though not significant, AT2 receptor levels were observed to decrease with increasing doses of letrozole. CONCLUSIONS: Letrozole can induce significant changes in some RAS related genes. These alterations are important to understand the pathways and consequences beyond cardiac events induced by breast cancer treatments.

Whole-Body Vibration Training Increases Myocardial Salvage Against Acute Ischemia in Adult Male Rats.

BACKGROUND: Whole body vibration training (WBV) is a new training program, which is safe and effective. It can be followed by the public. However, data on the safety and efficacy of vibration on myocardial ischemia reperfusion (IR) injury are lacking. OBJECTIVE: To examine the effect of WBV on the tolerance of the myocardium to acute IR injury in an experimental rat model. METHODS: Twenty-four male Wistar rats were divided into control and vibration groups. Vibration training consisted of vertical sinusoidal whole body vibration for 30 min per day, 6 days per week, for 1 or 3 weeks (WBV1 and WBV3 groups, respectively). All the rats were submitted to myocardial IR injury. Myocardial infarct size and ischemia-induced arrhythmias were assessed. Differences between variables were considered significant when p < 0.05. RESULTS: No differences were observed between the groups regarding the baseline hemodynamic parameters. Infarct size was smaller in the experimental group (control, 47 ± 2%; WBV1, 39 ± 2%; WBV3, 37 ± 2%; p < 0.05, vs. control). Vibration produced a significant decrease in the number and duration of ventricular tachycardia (VT) episodes compared to the control value. All ventricular fibrillation (VF) episodes in the vibration groups were self-limited, while 33% of the rats in the control group died due to irreversible VF (p = 0.02). CONCLUSION: The data showed that vibration training significantly increased cardiac tolerance to IR injury in rats, as evidenced by reduction in the infarct size and cardiac arrhythmias, and by facilitating spontaneous defibrillation.

Attenuation of Sulfite-Induced Testicular Injury in Rats by Zingiber officinale Roscoe.

Sulfite salts, including sodium metabisulfte, are widely used as preservatives in foods and pharmaceutical agents. Previous studies suggest that oxidative stress may be an important mediator of testicular injury. The present study was designed to elucidate the effect of exposure to sodium metabisulfite by gavage without or with Zingiber officinale (ginger) extract on the rat testes. Thirty-two male Wistar rats were randomly divided into control, ginger-treated (500 mg/kg/day), sodium metabisulfite- (SMB-) treated (260 mg/kg/day), and SMB + ginger- (SZ-) treated groups. After 28 days, the rats were anesthetized by ether and, after laparotomy, blood was collected from the heart to determine testosterone level by the enzyme-linked immunosorbent assay (ELISA) kit. Then left testes and cauda epididymis of all animals were removed for histological examination and sperm analysis, and right testes were removed for assessing lipid peroxidation (indexed by malondialdehyde [MDA]) and antioxidant enzymes. The results showed that spermatogenesis, epididymal morphometry, and sperm parameters were affected by SMB. There was a significant increase in MDA level and a significant reduction in the activities of glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT) in the SMB-treated rats compared to the control. Ginger treatment of SMB-exposed rats significantly increased testosterone level and the number of different spermatogenic cells. The level of MDA reversed to the control levels and the activities of GPx and GR were significantly increased when SMB was coadministered with ginger extract. It is concluded that coadministration of ginger, through its antioxidant and androgenic properties, exerts a protective effect against SMB-induced testicular oxidative stress.

The effects of pentobarbital, ketamine-pentobarbital and ketamine-xylazine anesthesia in a rat myocardial ischemic reperfusion injury model.

To achieve reliable experimental data, the side-effects of anesthetics should be eliminated. Since anesthetics exert a variety of effects on hemodynamic data and incidence of arrhythmias, the selection of anesthetic agents in a myocardial ischemic reperfusion injury model is very important. The present study was performed to compare hemodynamic variables, the incidence of ventricular arrhythmias, and infarct size during 30 min of ischemia and 120 min of reperfusion in rats using pentobarbital, ketamine-pentobarbital or ketamine-xylazine anaesthesia. A total of 30 rats were randomly divided into three groups. In group P, pentobarbital (60 mg/kg, intraperitoneally [IP]) was used solely; in group K-P, ketamine and pentobarbital (50 and 30 mg/kg, respectively, IP) were used in combination; and in group K-X, ketamine and xylazine (75 and 5 mg/kg, respectively, IP) were also used in combination. Hemodynamic data and occurrence of ventricular arrhythmias were recorded throughout the experiments. The ischemic area was measured by triphenyltetrazolium chloride staining. The combination of ketamine-xylazine caused bradycardia and hypotension. The greatest reduction in mean arterial blood pressure during ischemia was in the P group. The most stability in hemodynamic parameters during ischemia and reperfusion was in the K-P group. The infarct size was significantly less in the K-X group. Whereas none of the rats anesthetized with ketamine-xylazine fibrillated during ischemia, ventricular fibrillation occurred in 57% of the animals anesthetized with pentobarbital or ketamine-pentobarbital. Because it offers the most stable hemodynamic parameters, it is concluded that the ketamine-pentobarbital anesthesia combination is the best anesthesia in a rat ischemia reperfusion injury model.

The effect of high intensity interval training on cardioprotection against ischemia-reperfusion injury in wistar rats.

The aims of the present study were to determine whether short term high intensity interval training (HIIT) could protect the heart against ischemia reperfusion (IR) injury; and if so, to evaluate how long the exercise-associated protection can be lasted. Sixty-three rats were randomly assigned into sedentary (n = 15), sham (n = 7), and exercise groups (n = 41). Rats in the exercise groups performed 5 consecutive days of HIIT on treadmill: 5 min warm up with 50 % VO2max, 6×2 min with 95-105 % VO2max (about 40 to 45 m/min), 5×2 min recovery with 65-75 % VO2max (about 28 to 32 m/min), and 3 min cool down with 50 % VO2max, all at 0 % grade. Animals exposed to an in vivo cardiac IR surgery, performed at days 1, 7, and 14 following the final exercise session. Ischemia-induced arrhythmias, myocardial infarct size (IS), plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities were measured in all animals. Compared to sedentary rats, exercised animals sustained less IR injury as evidenced by a lower size of infarction and lower levels of LDH and CK at day one and day 7 post exercise. In comparison of sedentary group, IS significantly decreased in EX-IR1 and EX-IR7 groups (50 and 35 %, respectively), but not in EX-IR14 group (19 %). The exercise-induced cardioprotection disappeared 14 days following exercise cessation. There were no significant changes in ischemia-induced arrhythmia between exercised and sedentary rats. The results clearly demonstrate that HIIT protects the heart against myocardial IR injury. This protective effect can be sustained for at least one week following the cessation of the training.

Sodium metabisulfite-induced changes on testes, spermatogenesis and epididymal morphometric values in adult rats.

BACKGROUND: Sulphites are widely used as a preservative and antioxidant additives in the food and pharmaceutical industries. Many types of biological and toxicological effects of sulphites in multiple organs of mammals have been shown in previous studies. OBJECTIVE: The aim of this study was to investigate the effects of sodium metabisulfite (SMB) on testicular function and morphometric values of epididymis in adult male Wistar rats. MATERIALS AND METHODS: A total of 32 rats were randomly divided into four groups. The experimental groups received SMB at doses of 10 mg/kg (S10), 100mg/kg (S100), and 260 mg/kg (S260) while an equal volume of normal saline was administered to the control group via gavage. The rats were anaesthetized after 28 days and the left testis with the head of epididimis was excised following abdominal incision for histological observation using hematoxylin and eosin staining. Serum samples were collected for assay of testosterone level. The initial epididymis was analyzed for motility, morphology, and the number of sperms. RESULT: The results of this study showed that normal morphology, count, and motility of sperms and testosterone level were decreased in the SMB treated groups. In comparison with the control group, SMB resulted in a lower total number of spermatogonia, primary spermatocyte, spermatids, and Leydig cells. CONCLUSION: It is suggested that SMB decreases the sperm production and has the potential to affect the fertility adversely in male rats.

Combined 1,25-Dihydroxy-vitamin D and Resveratrol: A Novel Therapeutic Approach to Ameliorate Ischemia Reperfusion-Induced Myocardial Injury.

The aim of this study was to assess the effect of combined 1,25-dihydroxyvitamin D (1,25 D) and resveratrol on cardiac arrhythmias, infarct size, and transcription of catalase, thioredoxin-1 and B-cell lymphoma 2 (Bcl-2), following myocardial ischemia-reperfusion (IR) in male rats. Ligation of coronary artery was performed in rats (n = 6 per group) without any treatment (IR group), pretreated with 0.1 µg/kg/day of 1,25 D (1,25 D + IR), 1 mg/kg/day of resveratrol (Res + IR) or a combination (1,25 D + Res + IR) for 14 days. Arrhythmias were analyzed according to the Lambeth conventions, and infarct size was measured by 2,3,5-triphenyl-2H-tetrazolium chloride staining. Expression of prosurvival genes was evaluated by real-time polymerase chain reaction. In the 1,25 D + Res + IR group the mean infarct size was 17.6 ± 3.5 %, which was significantly less than that in the IR, 1,25 D + IR, and Res + IR groups (p < 0.001). Although the single therapy of either 1,25 D or resveratrol did not change the incidence of arrhythmias significantly, a reduction in the number of ventricular ectopic beats was noted in group 1,25 D + Res + IR (179.19 ± 58.87, p < 0.001 vs IR; p < 0.05 vs Res + IR; p < 0.01 vs Vit D + IR). Combination of 1,25 D and resveratrol increased transcription of catalase by 119 ± 37 % (p < 0.001 vs IR, p < 0.01 vs Res + IR, p < 0.001 vs 1,25 D + IR). Our study showed that combination of a non-hypotensive dose of 1,25 D and resveratrol can be a novel and effective strategy for protecting against ischemia.

The effect of educational programs on hypertension management.

BACKGROUND: Hypertension is the main risk factor for cardiovascular diseases and stroke. Blood pressure control is a challenge for healthcare providers and the rate of blood pressure control is not more than 50% worldwide. OBJECTIVES: The present study aimed to determine the effectiveness of a short-term educational program on the level of knowledge, lifestyle changes, and blood pressure control among hypertensive patients. PATIENTS AND METHODS: This quasi-experimental study was conducted on the hypertensive patients attending Shiraz Healthy Heart House. In this study, 112 patients were selected via systematic random sampling. The study data were collected using a data gathering form which consisted of baseline characteristics and measurements of blood pressure. Multivariate analyses were used to assess the relationship between education and hypertension. RESULTS: At baseline, the scores of aware, treated, and controlled hypertensive patients were 21%, 20%, and 12%, respectively. However, these measures were increased to 92%, 95%, and 51%, respectively at the end of the study. The mean knowledge scores improved from 2.77 ± 2.7 to 7.99 ± 1.78 after 3 months (P < 0.001). Also, the mean lifestyle scores changed from 3.15 ± 1.52 to 4.53 ± 1.23 (P < 0.001). CONCLUSIONS: The results of the current study indicated that the educational programs were effective in increasing knowledge, improving self-management, and controlling detrimental lifestyle habits of the patients with hypertension.

Aortic distensibility in bicuspid aortic valve patients with normal aortic diameter.

OBJECTIVE: Bicuspid aortic valve (BAV) is associated with aortic abnormalities. The ascending aorta tends to dilate and its elasticity deteriorates. The morphology of the BAV and the elasticity of the proximal ascending aorta seem to influence the outcome. This study aimed to determine the distensibility of the ascending aorta with normal diameter in BAV patients and its relation to its morphology. METHODS: This is a cross-sectional study. In the patients with BAV referred for echocardiography, the phenotype was defined as anteroposterior (AP) or mediolateral (ML) leaflet orientations. The aortic distensibility at 5-10 mm above the sinotubular junction was assessed using transthoracic echocardiography in 50 BAV patients, and 50 healthy controls with tricuspid aortic valve (TAV) matched by gender and age. RESULTS: The ascending aorta in BAV patients had less distensibility compared with that in the control subjects (0.00298 ± 0.0023 versus 0.00805 ± 0.0028 cm2 dynes-1 × 10-6, respectively, p < 0.001). The ML phenotype of BAVs was more frequent. However, the reduced distensibility was not related to gender and morphology of the valve. CONCLUSIONS: Regardless of the valve morphology and also in the absence of aortic dilation, aortic distensibility is impaired in BAV subjects compared with TAV subjects. This finding supports the idea of an intrinsic aortic wall anomalies underlying the impaired elasticity of the aorta in BAV patients.

Expressional profile of cardiac uncoupling protein-2 following myocardial ischemia reperfusion in losartan- and ramiprilat-treated rats.

BACKGROUND AND AIMS: The aim of this study was to investigate the early changes of cardiac uncoupling protein-2 (UCP2) expression following myocardial ischemia reperfusion in rats chronically treated with ramiprilat and losartan. METHODS: Male Wistar rats were assigned into seven groups (six in each): intact (control); sham-operated; nontreated rats subjected to ischemia and reperfusion (IR); ramiprilat-treated rats with (Ram+IR) and without ischemia (Ram); losartan treated with (Los+IR) and without ischemia (Los). Quantitative evaluation of UCP2 mRNA was carried out using real-time reverse transcription-polymerase chain reaction (RT-PCR). Mitochondria were isolated, and protein expression was quantified by Western blotting. RESULTS: In IR group: UCP2 protein but not mRNA level was increased in the ischemic area of the left ventricle (LV) (172% ± 26.7, p < 0.001 vs. LV of control). Following acute myocardial IR, UCP2 protein levels was increased in the ischemic area of the LV but not in RV, suggesting the local effect of ischemia on UCP2 expression. IR-induced overexpression of UCP2 was suppressed by ramiprilat and losartan. CONCLUSION: These findings suggest that losartan and ramiprilat can suppress UCP2 expression following myocardial IR, and by this mechanism may protect the myocardium against IR injury.

The effects of co-administration of opium and morphine with nicotine during pregnancy on spatial learning and memory of adult male offspring rats.

OBJECTIVES: Smoking opium/cigarette is a global health concern. The aim of this study was to examine learning and memory of rat male offsprings whose mothers had been exposed to either opium or morphine with nicotine during pregnancy. MATERIALS AND METHODS: Wistar rats were used for the experiments. In the female rats, opium, morphine and nicotine dependencies were induced by daily injections of drug solution for 10 days before mating. Spatial memory was tested by Morris water maze test in male pups at the postnatal day 60. The duration that took until the rats found the platform in the maze and also their swimming speed were recorded. RESULTS: An increase in the platform finding duration was observed for the pups of dependent mothers in comparison with the control in the training trial (P<0.05). Prenatal exposure to opium/morphine and nicotine significantly decreased the time spent in the trigger zone to find the hidden platform (P<0.05) but had no significant effect on the swimming speed in the probe test. However, no significant difference was observed in the learning and memory behavior of offspring whose mothers received morphine, opium, nicotine or the co-administration of either morphine or opium with nicotine. CONCLUSION: The present study showed that the opium, morphine and nicotine abuse and co-administration of opium/morphine with nicotine during pregnancy may cause deficits in spatial learning of male rat offspring. Based on our data, no synergistic effects of co-drug administration were observed on learning and memory in male rat offspring.

Effects of atorvastatin on the hypertension-induced oxidative stress in the rat brain.

BACKGROUND: It is well known that the development of brain oxidative stress is one of the most serious complications of arterial hypertension that evokes brain tissue damage. The aim of this study was to examine the effects of atorvastatin treatment (20 mg/kg/day), as an antioxidant, to prevent the brain tissue oxidative stress in the hypertensive (HTN) rats. METHODS: Experiments were performed in four groups of rats (n = 5 each group): sham, sham-treated, HTN and HTN treated. Rats were made HTN by aortic constriction above the renal arteries. After 30 days, rats were slaughtered under deep anesthesia to remove brain hemispheres. After tissue homogenization, enzyme activities of superoxide dismutase (SOD) and catalase (CAT), as well as glutathione (GSH) content and malondialdehyde (MDA) level were determined by biochemical methods. RESULTS: In HTN rats, arterial blood pressure was increased about 40% and brain enzyme activities of SOD and CAT were significantly decreased compared with sham group. Induction of hypertension significantly decreased GSH content and increased MDA level of brain tissue. Treatment with atorvastatin enhanced the activity of SOD and prevented from GSH decrement during hypertension. CONCLUSION: Based on the findings of this study, treatment with atorvastatin might have saved the brain tissue of HTN rats from hypertension-induced oxidative stress.

The effects of Artemisia aucheri extract on hepatotoxicity induced by thioacetamide in male rats.

OBJECTIVE: Liver is an important organ that is exposed to many oxidant and carcinogenic agents, thus antioxidant compounds are beneficial for liver health. Artemisia contains flavonoid compounds and anti-diabetic, antioxidant, and anti-inflammatory properties. Due to possessing terpene and sesquiterpene compounds, this plant has antioxidant properties. This study was done to investigate the effects of Artemisia plant extract on thioacetamide-induced hepatotoxicity in Wistar rats. MATERIALS AND METHODS: For induction of hepatotoxicity, 50 mg/kg thioacetamide was injected intraperitoneally (i.p). After extraction and purification, the hydroalcoholic extract was injected i.p. at 100, 200, and 300 mg/kg doses for 21 days together with thioacetamide at 50 mg/kg dose in the last 3 days. After blood sampling and separation of serum, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), albumin, and total protein concentrations were measured. RESULTS: Significant decreases in aminotransferase and alkaline phosphatase activities and significant increases in the concentration of albumin and total protein in groups treated with the extract compared with thioacetamide-treated group were observed (p<0.05). CONCLUSION: The results indicate that protective effects of Artemisia extract against the thioacetamide-induced hepatotoxicity may be due to its ability to block the bioactivation of thioacetamide, primarily by inhibiting the activity of Cyp450 and free radicals. Artemisia possesses quercetin. Studies have demonstrated that quercetin inhibits lipid peroxidation and as an antioxidant can inhibit lipid peroxidation.

The impact of education on weight loss in overweight and obese adults.

BACKGROUND: Prevalence of obesity is rapidly rising. To reverse the obesity epidemic, efforts should be made to incorporate intensive weight loss programs into medical practice. The primary aim of this study was to change the behavior for achieving a mean weight loss of 5-10% of initial body weight over 6 months in overweight and obese adults. METHODS: In this quasi-experimental study, 266 out of 533 subjects screened for coronary heart disease risk factors in Shiraz Healthy Heart House were overweight or obese. 140 individuals with BMI≥25 completed this study's 6 month program. The subjects were visited on day 1 and at 2 week intervals and taught intensive lifestyle modification. The subjects who did not lose 5% of their initial body weight after 3 months were assigned to receive 120 mg orlistat three times daily for 3 months in addition to counseling sessions. The main outcome measures were body weight and BMI. RESULTS: The mean weight and BMI of participants were 78.6±10.7 kg and 30±0.2 kg/m2, respectively. Women included 58% of the sample. 110 subjects (78.5%) lost ≥5% of their initial body weight during 3 months. The Mean weight and BMI loss in these subjects were 7.6±0.8 kg and 2.4±0.3 kg/m2, respectively. CONCLUSIONS: Teaching of how to modify lifestyle and to gain more self-control with eating have the major role in reducing weight and BMI. So, training accompanied by continual follow up for performing the instructions could lead to favourable results.

Cardiac effects of cupping: myocardial infarction, arrhythmias, heart rate and mean arterial blood pressure in the rat heart.

This study was carried out to determine the effects of cupping on hemodynamic parameters, arrhythmias and infarct size (IS) after myocardial ischemic reperfusion injury in male rats. Rats were randomly subjected to dry or wet cupping. While dry cupping simply involved stimulation of the skin by suction, in wet cupping, scarification of the back skin was also carried out with a surgical blade and 0.5 ml blood was sucked out in each session. For ischemic reperfusion injury, rats were subjected to 30 min of left anterior descending coronary artery occlusion and 120 min of reperfusion. Our results show that cupping did not change the baseline heart rate or mean arterial blood pressure. Ischemic reperfusion injury caused an IS of 50 ± 5%, whereas dry cupping, single and repeated wet cupping significantly reduced IS to 28 ± 3%, 35 ± 3% and 22 ± 2% of area at risk, respectively. The rate of ischemic induced arrhythmias was significantly modified by wet cupping (P < 0.05). These results indicate for the first time in rats that cupping might be cardioprotective in the ischemic reperfusion injury model.

Protective effect of crocin against reperfusion-induced cardiac arrhythmias in anaesthetized rats.

The aim of the present study was to investigate the effects of crocin - a natural antioxidant derived from saffron - on cardiac reperfusion-induced arrhythmia and antioxidant systems such as catalase and superoxide dismutase (SOD) enzyme activities, glutathione (GSH) and malondialdehyde (MDA, as a marker of lipid peroxidation) levels. Rats in 4 experimental groups were administered crocin (20 mg/kg/day) or vehicle (i.p.) for 21 days with or without cardiac ischemia-reperfusion (IR). At the end of this period, hearts of anaesthetized animals in IR and "Cr + IR" groups were subjected to 10 min occlusion of the left anterior descending coronary artery and thereafter reperfused for 30 min. The results suggest that crocin is partially capable of suppressing reperfusion-induced arrhythmias. Compared to control group, ischemic-reperfusion injury significantly decreased SOD activity and GSH level and increased MDA level of heart muscle. "Cr + IR" group showed remarkably increased catalase activity in heart tissue (28.7 ± 6.6 vs. 23.6 ± 4.1 U/mg protein, P < 0.05) compared to the IR group. The level of cardiac tissue SOD activity in the "Cr + IR" group animals did not decline significantly compared to rats that were administered crocin alone with no ischemia. The results suggest a protective role of crocin on cardiac reperfusion arrhythmias which may at least partially be related to stability or even amplification of antioxidant systems. Crocin may potentially be useful for treatment or prevention of arrhythmias in patients with ischemic heart disease and this issue remains to be investigated in future clinical studies.

Influence of ramiprilat and losartan on ischemia reperfusion injury in rat hearts.

UNLABELLED: HYPOTHESIS/INTRODUCTION: Our aim was to investigate whether a non-hypotensive dose of ramiprilat and losartan has myocardial protective effects during myocardial ischemia/reperfusion in vivo. MATERIALS AND METHODS: Three groups of rats were given 10 mg/kg per day of losartan for one (L-1W), four (L-4W) or 10 (L-10W) weeks. Another three groups were given 50 µg/kg per day of ramiprilat for one (R-1W), four (R-4W) or 10 (R-10W) weeks. The animals underwent 30 min of left anterior descending artery occlusion and subsequent reperfusion for 120 min. RESULTS: Myocardial infarct size (IS) was reduced in R-1W (28.4 ± 6.3%, p < 0.001), R-4W (27.8 ± 7.4, p < 0.001), L-4W (31.8 ± 6%, p < 0.05) and L-10W (25.3 ± 5.7, p < 0.001) groups compared with a saline group (48.3 ± 7.8%). A significant reduction in the number of ventricular ectopic beats (VEBs) was noted in groups R-1W (209 ± 41, p < 0.01), R-4W (176 ± 39, p < 0.01), L-4W (215 ± 52, p < 0.05) and L-10W (191 ± 61, p < 0.01 vs. saline 329 ± 48). The incidence of irreversible ventricular fibrillation (VF) and mortality were decreased significantly only in L-10W group. There were no significant decreases in episodes of VT, the incidence of irreversible VF and mortality in all of the groups treated with ramiprilat. CONCLUSION: These data indicate that losartan and ramiprilat protect the heart against ischemia/reperfusion injury independently of their hemodynamic effects but in a time-dependent manner.