Comparison of the preconditioning effect of different exercise training modalities on myocardial ischemia-reperfusion injury

The study of exercise preconditioning can develop strategies to prevent cardiovascular diseases and outline the efficient exercise model. However, the exercise type with the most protective effect against ischemia-reperfusion injury is unknown. In this study, we examined the effects of three kinds of exercise preconditioning on myocardial ischemia-reperfusion in adult rats and explored the possible underlying mechanisms. Male Wistar rats subjected to ten weeks of endurance, resistance, and concurrent training underwent ischemia (30 min) and reperfusion (120 min) induction. Then, infarction size, serum levels of the CK-MB, the redox status, and angiogenesis proteins (VEGF, ANGP-1, and ANGP-2) were measured in the cardiac tissue. Results showed that different exercise training modes have the same reduction effects on infarction size, but ischemia-reperfusion-induced CK-MB was lower in response to endurance training and concurrent training. Furthermore, cardiac VEGF levels increased in all three kinds of exercise preconditioning but ischemia-reperfusion-induced ANGP-1 elevated more in endurance training. The cardiac GPX activity was improved significantly through the resistance and concurrent exercise compared to the endurance exercise. In addition, all three exercise preconditioning models decreased MPO levels, and ischemia reperfusion-induced MDA was lower in endurance and resistance training. Overall, these results indicated that cardioprotection of exercise training against ischemia-reperfusion injury depends on the exercise modality. Cardioprotective effects of aerobic, resistance, and concurrent exercises are due to different mechanisms. The preconditioning effects of endurance training are mediated mainly by pervasive angiogenic responses and resistance training through oxidative stress amelioration. The preconditioning effects of concurrent training rely on both angiogenesis and oxidative stress amelioration.

The role of hypoxia related hormones responses in acute mountain sickness susceptibility individuals unaccustomed to high altitude

Acute mountain sickness (AMS) is caused by rapid ascent to altitude (>2500 m) and remains a poorly understood pathophysiological condition. Accordingly, we investigated the relationship between acute exposure to high altitude and hypoxia related biochemical proteins. 21 healthy subjects (Female (8) and male (13), Age: 36.7±8.5, BMI: 23.2±3.1) volunteers participated in this project and fasting blood samples were taken before (sea level) and after 1 and 24-h exposure to high altitude (3,550 m). Blood oxygen saturation (SpO2), AMS status (Lake Louise Score) and serum HIF-1, Endothelin-1, VEGF and Orexin-A were measured (via ELISA) at 1, 6 and 24 h after exposure to high altitude. Pre-ascent measurement of hypoxia related proteins (Orexin-A, HIF-1, VEGF and Endothelin-1) where all significantly (<0.05) higher in the AMS-resistant individuals (No-AMS) when compared to AMS susceptible individuals (AMS+). Upon ascent to high altitude, 11 out of 21 volunteers had AMS (10.1±0.6 in AMS+ vs. 0.9±0.6 in No-AMS, P<0.05) and presented with lower resting SpO2 levels (77.7±0.4 vs. 83.5±0.3 respectively, p<0.05). Orexin-A, HIF-1, VEGF and Endothelin-1, significantly increased 24 hrs after exposure to high altitude in both AMS+ and No-AMS. The response of Orexin-A was similar between two groups, also, HIF-1 elevation 24 hrs after exposure to altitude was more in AMS+ (13% vs. 19%), but the increase of VEGF and Endothelin-1, 1 and 24 hrs after exposure to altitude in No-AMS was double that of AMS+. Hypoxia related proteins include Orexin-A, HIF-1, VEGF and Endothelin-1 may play a pathophysiological role in those who are susceptible to AMS.

The preconditioning effect of different exercise training modes on middle cerebral artery occlusion induced-behavioral deficit in senescent rats

Introduction

Brain abilities decrease after brain stroke in elderly. The neuroprotective effect of exercise training has been proved in clinical trials and animal experiment. Nevertheless, it is not still clear what kind of exercise has greater protective effect. The present study aimed at investigating pre-conditioning effect of endurance, resistance, and concurrent training on learning ability, anxiety, and spatial memory in aged rats following stroke strength with middle cerebral artery occlusion.

Method

We used 50 male Wistar rats (age = 24 months) that were assigned randomly in five groups; 1: sham group, 2: Control group 3: Endurance training 4: Resistance training, and 5: concurrent training. The exercise training groups received training for four weeks. Following training, middle cerebral artery occlusion was applied to induce cerebral ischemia. Using the elevated plus maze, shuttle box test, and Morris water maze, neurocognitive functions were tested in the sample rats.

Results

It was found that resistance training did not affect spatial memory in the acquisition phase, while concurrent training and endurance training enhanced spatial memory in the acquisition phase. On the contrary, spatial memory was improved by resistance training in the retention phase, while concurrent and endurance exercises did not affect spatial memory in the retention phase. Passive avoidance learning ability at acquisition phase was more in resistance group compared to the endurance and concurrent training in shuttle box test, but in retention phase was similar between training groups. Unlike endurance and concurrent training, resistance training reduced anxiety in senescent rats.

Conclusion

All three exercise types alleviated aversive learning and memory impairment induced by stroke in senescent rats. Notably, the resistance training showed a greater protective effect compared to the other two training methods.

Intelligent modeling of hydrogen sulfide solubility in various types of single and multicomponent solvents

This study aims to study the solubility of acid gas, i.e., hydrogen sulfide (H₂S) in different solvents. Three intelligent approaches, including Multilayer Perceptron (MLP), Gaussian Process Regression (GPR) and Radial Basis Function (RBF) were used to construct reliable models based on an extensive databank comprising 5148 measured samples from 54 published sources. The analyzed data cover 95 single and multicomponent solvents such as amines, ionic liquids, electrolytes, organics, etc., in broad pressure and temperature ranges. The proposed models require just three simple input variables, i.e., pressure, temperature and the equivalent molecular weight of solvent to determine the solubility. A competitive examination of the novel models implied that the GPR-based one gives the most appropriate estimations with excellent AARE, R² and RRMSE values of 4.73%, 99.75% and 4.83%, respectively for the tested data. The mentioned intelligent model also performed well in describing the physical behaviors of H₂S solubility at various operating conditions. Furthermore, analyzing the William's plot for the GPR-based model affirmed the high reliability of the analyzed databank, as the outlying data points comprise just 2.04% of entire data. In contrast to the literature models, the newly presented approaches proved to be applicable for different types of single and multicomponent H₂S absorbers with AAREs less than 7%. Eventually, a sensitivity analysis based on the GPR model reflected the fact that the solvent equivalent molecular weight is the most influential factor in controlling H₂S solubility.

Interval training and Crataegus persica ameliorate diabetic nephropathy via miR-126/Nrf-2 mediated inhibition of stress oxidative in rats with diabetes after myocardial ischemia-reperfusion injury

Myocardial disorders are the most common cause of renal failure and mortality in diabetic patients, but the molecular mechanism of this process is not yet clear. The reduction of nuclear Erythroid2-related factor-2 (Nrf-2) and positive regulators of Nrf-2 proteins, such as DJ-1 and microRNA-126 (miR-126), after hypoxia and the promotion of reactive oxygen species, might be an intervention indicator in renal failure after myocardial ischemia-reperfusion. Therefore, this study evaluates the renoprotective effect of exercise training and Crataegus persica extract (CE) on myocardial ischemia-reperfusion-induced kidney injury in diabetic rats. Fifty rats were divided into five groups: healthy sedentary control (Con), sedentary diabetic (D), interval trained diabetic (TD), diabetic plus Crataegus persica extract treatment (CD), and interval trained diabetic plus Crataegus persica extract treatment (TCD) groups. The rats in the exercise groups were subjected to moderate-intensity interval training five days per week for ten weeks. The rats in CD and TCD groups received 300 mg/kg of Crataegus persica through gavage for ten weeks. Then, the subjects underwent 30 min of myocardial ischemia and subsequently reperfusion for 24 h. At the end of the experiment, insulin sensitivity, oxidative stress, renal function, histopathology of the kidney, Nrf-2, miR-126, and DJ-1 gene expression levels were evaluated. The results show that the treatments decreased elevated levels of renal oxidative stress, glomerular filtration rate, insulin sensitivity, and pathological score in diabetic rats. Also, the expression of Nrf-2 and miR-126, unlike DJ-1, decreased in diabetic rats due to interval training. Due to the results, diabetes aggravates acute myocardial ischemia-reperfusion-induced kidney injury, while moderate-intensity interval training and Crataegus persica treatment simultaneously ameliorate myocardial ischemia-reperfusion-induced renal injury via miR-126/Nrf-2 pathway and improve insulin sensitivity and renal function in type 1 diabetic rats.

Cardioprotective effects of exercise preconditioning on ischemia-reperfusion injury and ventricular ectopy in young and senescent rats

BACKGROUND

Aging decreases ischemic tolerance, while exercise prevents myocardial ischemia reperfusion (IR) injury. The cardioprotective role of high intensity interval training (HIIT), however, is unknown.

METHODS

Accordingly, we investigated 8 weeks (5 days/week, 40 min/day) of HIIT treadmill exercise (60%/90% of VO₂ peak) on IR injury in young (2-month) and senescent (20-month) Wistar rat myocardia (N = 10/group). Surgical IR (30 min/120 min) was performed via reversible left anterior descending artery ligation and ECG was analyzed to determine ventricular ectopy during IR period.

RESULTS

Infarction size and oxidative stress were measured in hearts post-mortem. Glutathione peroxidase activity and Myeloperoxidase levels were mitigated with age, but elevated post IR. HIIT potentiated antioxidant defenses in young and old hearts, and infarction size was lower in young HIIT trained. Metrics of reactive oxygen species were not lower after IR, and were not affected by HIIT in young or old rats. Ventricular ectopy score in senescent rats was insignificantly more than young rats and HIIT significantly decreased ventricular ectopy score in young and senescent rats.

CONCLUSIONS

Findings indicate that IR tolerance is mitigated in senescent hearts, while HIIT ameliorated infarction by increasing antioxidant enzymes activity in young and senescent hearts.

Swimming training and Plantago psyllium ameliorate cognitive impairment and glucose tolerance in streptozotocin-nicotinamide-induced type 2 diabetic rats

Brain malfunction is common in diabetic patients. On the other hand, a growing body of research points to the beneficial effect of medicinal plants and exercise training on insulin sensitivity and brain function. Therefore, the aim of the present study was to investigate the effect of co-administration of swimming training and Plantago psyllium (mixed with standard pelleted food at a weight ratio of 5%) on learning and memory impairment and glucose tolerance in type 2 diabetic rats. For this purpose, 10 healthy and 40 rats with type 2 diabetes were randomly allocated to five groups: healthy sedentary control group (Con), sedentary diabetic group (D), diabetic group subjected to swimming training (D + Tr), diabetic group receiving P. psyllium (D + Ps), and diabetic group subjected to swimming training and receiving P. psyllium (D + Ps + Tr). Diabetes was induced by a single intraperitoneal injection of nicotinamide (120 mg/kg) and streptozotocin (65 mg/kg) separately with 15 min intervals. Experimental groups were treated with swimming training and P. psyllium independently and simultaneously for 12 weeks. Lipid profile and food intake were measured and also, glucose tolerance was evaluated by glucose area under the curve (AUCg) using an oral glucose tolerance test. Passive avoidance learning (PAL) and memory were evaluated by shuttle box test and cognitive memory was assessed by novel object recognition (NOR) and elevated plus-maze (EPM) tests. Diabetic rats exhibited a significant increase in food intake, lipid profile, and AUCg compared to healthy rats. Step-through latency in the PAL acquisition trial (STL-a) and retention test (STL-r) were significantly lower in diabetic rats than in the control group. In the diabetic group without treatment, time spent in the dark compartment increased compared to the control group in the shuttle box test. Discrimination index and distance traveled reduced in diabetic rats. On the other hand, swimming training and P. psyllium alleviated food intake, lipid profile, and glucose tolerance in diabetic rats. Also, the STL-a, STL-r, discrimination index, and distance travelled in the D + Ps + Tr group were significantly more than the diabetic group. Results showed that 12 weeks of swimming training and receiving P. psyllium improved memory deficit in streptozotocin-nicotinamide-induced type 2 diabetic rats possibly through hypolipidemic and hypoglycemic effects. These results suggest that the administration of swimming training and P. psyllium simultaneously might be an effective intervention for the treatment of diabetes-induced behavioral deficits.

Effects of Resistance, Endurance, and Concurrent Exercise on Oxidative Stress Markers and the Histological Changes of Intestine After Morphine Withdrawal in Rats

Objectives: The aim of this study was to evaluate the effects of resistance, endurance, and concurrent exercise on oxidative stress markers and histological changes of the intestine after morphine withdrawal in rats. Methods: A total of 30 male Wistar rats were randomly divided into 5 groups (n=6) including healthy control, withdrawal (rat received morphine for 21 days and 8 weeks of withdrawal period), withdrawal + endurance exercises, withdrawal + resistance exercises, and withdrawal + concurrent exercises. The rats practiced endurance, resistance, and concurrent exercises for 10 weeks. Then, their intestines were removed and used for biochemical and histological analysis. Next, several factors were measured such as total protein levels, malondialdehyde (MDA), reduced glutathione (GSH), total antioxidant capacity (TAC), and total oxidant status (TOS). Finally, the morphological alteration of intestine was examined under the light microscope. Results: Morphine withdrawal significantly increased the levels of MDA in the intestine of withdrawal rats compared to those of the control group while endurance, resistance, and concurrent exercise reduced the MDA levels in the intestine. In addition, morphine withdrawal led to a decrease in TAC and GSH levels in the intestine compared to control rats whereas endurance, resistance, and concurrent exercise noticeably increased TAC and GSH levels. Interestingly, the change in the concurrent group was more significant. Moreover, the levels of TOS demonstrated a significant increase in the addicted rat as compared to the control group. Conversely, endurance, resistance, and concurrent exercise significantly decreased TOS levels and the reduction was more significant in the concurrent group. Finally, the intestine of withdrawal rat was morphologically abnormal while it restored by the exercise. Conclusion: Overall, endurance, resistance, and concurrent exercise significantly normalized oxidative stress and the morphological changes of the intestine in withdrawal rats.

Aerobic training and L-arginine supplement attenuates myocardial infarction-induced kidney and liver injury in rats via reduced oxidative stress

Introduction

The aim of the present study was to determine the effect of exercise training and l-arginine supplementation on kidney and liver injury in rats with myocardial infarction (MI).

Material and methods

Four weeks after MI, 50 male wistar rats randomly divided into five followed groups: sham surgery without MI (Sham, n = 10), Sedentary-MI (Sed-MI, n = 10) 3: L-Arginine-MI (La-MI, n = 10) 4: Exercise training-MI (Ex-MI, n = 10) and 5: Exercise and L-arginine-MI (Ex + La-MI). Ex-MI and Ex + La-MI groups running on a treadmill for 10 weeks with moderate intensity. Rats in the L-arginine-treated groups drank water containing 4% L-arginine. Tissues oxidative stress and kidney and liver functional indices were measured after treatments.

Result

Urea as a kidney function indexes, increased in Sed-MI group in compared to sham group and decreased significantly in Ex-MI and Ex + La-MI groups. The level of catalase (CAT) and glutathione stimulating hormone (GSH) of kidney were significantly lower in the MI-groups compared with the Sham group and kidney Malondialdehyde (MDA) levels increased after MI and significantly decreased in response to aerobic training and L-arginine. As well as, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as liver injury indices, increased in MI-groups and decreased by training and L-arginine. In this regards, liver MDA and CAT respectively increased and decreased in MI-groups, but aerobic training and L-arginine increased liver glutathione per-oxidase (GPx) and decreased liver MDA.

Conclusion

These results demonstrated that kidney and liver function impaired 14 weeks after MI and aerobic training and L-arginine supplementation synergistically ameliorated kidneys and liver injury in myocardial infarction rats through oxidative stress reduction.

Prediction of Maximal Oxygen Uptake by Six-Minute Walk Test and Body Mass Index in Healthy Boys

OBJECTIVE

To develop an equation to predict maximal oxygen uptake (VO2max) based on the 6-minute walk test (6MWT) and body composition in healthy boys.

STUDY DESIGN

Direct VO2max, 6-minute walk distance, and anthropometric characteristics were measured in 349 healthy boys (12.49 ± 2.72 years). Multiple regression analysis was used to generate VO2max prediction equations. Cross-validation of the VO2max prediction equations was assessed with predicted residual sum of squares statistics. Pearson correlation was used to assess the correlation between measured and predicted VO2max.

RESULTS

Objectively measured VO2max had a significant correlation with demographic and 6MWT characteristics (R = 0.11-0.723, P < .01). Multiple regression analysis revealed the following VO2max prediction equation: VO2max (mL/kg/min) = 12.701 + (0.06 × 6-minute walk distance _m) - (0.732 × body mass index_kg/m2) (R² = 0.79, standard error of the estimate [SEE] = 2.91 mL/kg/min, %SEE = 6.9%). There was strong correlation between measured and predicted VO2max (r = 0.875, P < .001). Cross-validation revealed minimal shrinkage (R²p = 0.78 and predicted residual sum of squares SEE = 2.99 mL/kg/min).

CONCLUSIONS

This study provides a relatively accurate and convenient VO2max prediction equation based on the 6MWT and body mass index in healthy boys. This model can be used for evaluation of cardiorespiratory fitness of boys in different settings.

Resistance training and hawthorn extract ameliorate cognitive deficits in streptozotocin-induced diabetic rats

It has been shown that diabetic rats display cognitive impairment. The aim of this study was to investigate the effects of resistance training and natural antioxidants on learning and memory in type 1 diabetic rats. For this purpose, fifty male Wistar rats were randomly divided into five groups: (i) Control (Con, n=10), (ii) Diabetic (D, n=10), (iii) Diabetic+Resistance training (DRT, n=10), (iv) Diabetic+natural antioxidants (DHE, n=10), and (v) Diabetic+Resistance training+ natural antioxidants (DRH, n=10). Climbing the ladder for a period of 5days/week for 10 consecutive weeks was considered as the resistance training model in our study. Natural antioxidants (100mg/kg per day) were administered to natural antioxidant groups for a period of 10 weeks. Moreover, spatial and passive avoidance learning and memory function were evaluated by Morris Water Maze (MWM) and shuttle box tests. The results showed that, mean of total escape latency decreased 25% (P<0.0001) in the DRH group compared with the D group in MWM. The percentage of time spent in the target quadrant identically decreased (34%) in the D and DHE groups compared with the Con group (p=0.001). In this regard, time spent in the dark Compartment (TDC) respectively rose 86% and 95% in the D and DHE groups compared with the Con group (p<0.05), and decreased 88% in the DRT and DRH groups compared with the D group in the shuttle box test (p<0.05). Furthermore, we noticed that total antioxidant capacity increase and lipid peroxidation decrease in response to the treatments in the diabetic rats as well. Therefore, the current study indicated that exercise training and natural antioxidants synergistically ameliorated learning and memory deficits in type 1 diabetic rats via reducing oxidative stress. Hence, it may propose a potential role of resistance training and natural antioxidants as an adjuvant therapy for the prevention and treatment of diabetic complications.

Endurance training induces fiber type-specific revascularization in hindlimb skeletal muscles of rats with chronic heart failure

Objective(s):

Previous studies showed that skeletal muscle microcirculation was reduced in chronic heart failure. The aim of this study was to investigate the effects of endurance training on capillary and arteriolar density of fast and slow twitch muscles in rats with chronic heart failure.

Materials and Methods:

Four weeks after surgeries (left anterior descending (LAD) artery occlusion), chronic heart failure rats were divided into 3 groups: Sham (Sham, n=10); Sedentary (Sed, n=10); Exercise training (Ex, n=10). Ex group rats were subjected to endurance training in the form of treadmill running with moderate intensity for 10 weeks.

Results:

Exercise training significantly increased capillary density and capillary to fiber ratio (P<0.05) in slow twitch muscle, but didn’t change fast twitch muscle capillary density and capillary to fiber ratio. Furthermore, arteriolar density in fast twitch muscle increased remarkably (P<0.05) in response to training, but slow twitch muscle arteriolar density did not change in response to exercise in chronic heart failure rats. HIF-1 increased (P<0.01) but VEGF and FGF-2 mRNA did not change in slow twitch muscle after training. In fast twitch muscle, HIF-1 mRNA increased (P<0.05), and VEGF and angiostatin decreased (P<0.01) significantly after training.

Conclusion:

Endurance training ameliorates fast and slow twitch muscle revascularization non-uniformly in chronic heart failure rats by increasing capillary density in slow twitch muscle and arteriolar density in fast twitch muscle. The difference in revascularization at slow and fast twitch muscles may be induced by the difference in angiogenic and angiostatic gene expression response to endurance training.

The impact of rapid weight loss (4%) on leptin, adiponectin, and insulin resistance in elite adult free style wrestlers

BACKGROUND

The effect of rapid weight loss program on adipocytokines is not yet clear. Therefore the aim of the present study was the effect of rapid weight loss (4%) on leptin, adiponectin, and insulin resistance in elite free style wrestlers.

METHODS

For this purpose, fifteen young freestyle wrestlers (weight 67.6±0.8, BMI 22.5±0.21 kg/m², body fat percent 6.12±0.18, waist to hip circumference ratio 0.82±0.08) in two weight categories (60 and 66 kg) were randomly selected. Caloric intake (mean 7 days measured by Food analyzer software) measured at 1 week before weight loss program by standard methods. Wrestlers performed a week rapid weight loss (average of 4% of body weight loss) protocol by caloric and water restriction by 60% (600-700 kcal per day), under the supervision of their coach. Anthropometric characteristics, leptin, adiponectin and insulin resistance were measured before and 12 and 36 hours after rapid weight loss program.

RESULTS

Rapid weight loss program with 4% of weight loss had a significantly reduced impact on anthropometric factors; leptin level, insulin resistance, and increased beta cell function, while the changes of adiponectin were not significant after rapid weight loss.

CONCLUSIONS

Findings of this study shows that rapid weight loss program significantly decreased leptin, L/A ratio and HOMA-IR, without significant changes on adiponectin levels. These changes may have harmful physiological effects on wrestlers' bodies but they can be useful to regulate of fatty acid, glucose metabolism, and insulin resistance.

Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction

Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-β and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-β and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 μm), TGF-β, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 μm diameters parallel to TGF-β overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 μm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-β and downregulation of angiostatin in MI rats.

Synergistic effects of nitric oxide and exercise on revascularisation in the infarcted ventricle in a murine model of myocardial infarction

It has been shown that density of microvessels decreases in the left ventricular after myocardial infarction (MI). The change of angiogenic and angiostatic factors as the main factors in revascularisation after exercise training in area at risk is not determined yet in MI. Therefore, the aim of the present study was the effect of exercise training and L-arginine supplementation on area at risk angiogenesis in myocardial infarction rat. Four weeks after surgery (Left Anterior Descending Coronary artery Ligation), myocardial infarction rats were divided into 4 groups: Sedentary rats (Sed-MI); L-arginine supplementation (La-MI); Exercise training (Ex-MI) and Exercise + L-arginine (Ex+La). Exercise training (ET) lasted for 10 weeks at 17 m/min for 10-50 min day(-1). Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. After ET and L-arginine supplementation, ventricular function was evaluated and angiogenic and angiostatic indices were measured at ~1 mm from the edge of scar tissue (area at risk). Statistical analysis revealed that gene expression of VEGF as an angiogenic factor, angiostatin as an angiostatic factor and caspase-3 at area at risk decrease significantly in response to exercise training compared to the sedentary group. The capillary and arteriolar density in the Ex groups were significantly higher than those of the Sed groups. Compared to the Ex-MI group, the Ex+La group showed a markedly increase in capillary to fiber ratio. No significant differences were found in infarct size among the four groups, but cardiac function increased in response to exercise. Exercise training increases revascularization at area at risk by reduction of angiostatin. L-arginine supplementation causes additional effects on exercise-induced angiogenesis by preventing more reduction of VEGF gene expression in response to exercise. These improvements, in turn, increase left ventricular systolic function and decrease mortality in myocardial infarction rats.

The impact of rapid weight loss on the leptin, adiponectin levels, and insulinresistance among adult free style wrestlers

AIM

Recent studies, shows the effective role of adipose tissue as an active endocrine organ. Leptin level increases in obese bodies while adiponectin as an antirisk factor reduction that contributes to decrease insulin resistance and anthropometric profiles. Hence, expected to the negative effects of weight loss on wrestlers' physiological function; leptin and adiponectin behaviors and insulin resistance in young wrestlers during their rapid weight loss program were examined.

METHODS

Fifteen young (23±1 yr) freestyle wrestlers with (weight 67.6±0.8 kg, BMI 22.5±0.2 kg/m²) in two (60 and 66 kg) weight categories were selected randomly. Caloric intake and anthropometric characteristics measured by standard methods. The leptin and adiponectin hormones and insulin resistance index were measured by sandwich and HOMA-IR methods respectively. Wrestlers performed a week rapid weight loss Protocol (average of 4% of body weight loss) under the supervision of their coach. Eventually, selected factors were measured after 12 and 24 hours of recovery, again.

RESULTS

The rapid weight loss (4%) program had a significantly reduced impact on anthropometric factors; leptin level, insulin resistance, and increased beta cell function, while the changes of adiponectin were not significant after weight loss.

CONCLUSION

Findings of this study shows that dramatic decrease in anthropometric factors follow the weight loss program that having a significant decrease on leptin, L/A ratio and HOMA-IR, without significant changes in adiponectin levels. These changes may have harmful physiological effects on wrestlers' bodies but they can be useful to regulate of fatty acid, glucose metabolism, and insulin resistance.

The correlation between resting serum leptin and serum angiogenic indices at rest and after submaximal exercise

BACKGROUND

The effect of leptin as stimulant angiogenic factor has been studied. But the association of leptin levels and exercise-induced angiogenesis has not been studied. Accordingly, the researchers investigated whether there were any differences in circulating serum VEGF, MMP-2 and MMP-9 among high and low resting leptin individuals at rest or in response to submaximal exercise.

MATERIALS AND METHODS

For this purpose the researchers defined two groups with high and low resting leptin levels. Fifteen subjects with high resting leptin (23.57±9.14ng/ml and Vo(2) max=29.46±3.62ml/kg.min) and fifteen subjects with low resting leptin level (1.04±0.49ng/ml and Vo(2) max=37.99±4.63ml/kgmin) exercised for 1h (1h) at 70% of Vo(2) max. Antecubital vein blood was collected at rest, immediately and 2h post exercise. Serum VEGF, MMP-2 and MMP-9 was measured by ELISA method.

RESULTS

Results of the study showed that the resting serum levels of VEGF, MMP-2 and MMP-9 didn't have any correlation with basic levels of leptin. In low leptin group the levels of VEGF and MMP-2 in immediately post exercise decreased significantly, but in high leptin group, only VEGF decreased significantly. 2h post exercise; the VEGF level in the low resting leptin group was significantly lower than that of its basal level. Beside, MMP-2 in the high and low basic levels of leptin groups were significantly increased compared to that of immediately post exercise. But the amount of MMP-9 did not change significantly in response to exercise in two groups. There were not any differences in the changes of VEGF, MMP-2 and MMP-9 in response to exercise between two groups. Furthermore, resting leptin had a significant correlation with V0(2) max.

CONCLUSION

The obtained results showed that the serum VEGF, MMP-2 and MMP-9 did not have any correlation with basic levels of leptin. In addition, it was concluded that levels of different resting leptin is ineffective on serum levels of VEGF, MMP-2 and MMP-9 at rest and in response to exercise in normal healthy subjects.