Effect of oligosaccharides on the antioxidant, lipid and inflammatory profiles of rats with streptozotocin-induced diabetes mellitus.

Prebiotics, gut microbiota-fermentable substances, delay the development of type I diabetes. In the present study, we investigated the effect of two prebiotics (galacto-oligosaccharides and xylo-oligosaccharides) on the antioxidant protection, lipid profile, and inflammatory activity of rats with streptozotocin-induced diabetes. The following markers were studied - malondialdehyde, 8-hydroxy-2'-deoxyguanosine, ferric reducing ability of plasma (FRAP), triacylglycerols, total cholesterol (TC), high-density lipoproteins, C-reactive protein (CRP), and interleukin-6. Diabetes was induced in male Wistar experimental rats by streptozotocin injection, while the non-diabetic controls were injected with saline. Afterward the oligosaccharides were administered orally to the experimental animals. The blood collected following the decapitation was analyzed by ELISA. A modified protocol was used only for measuring the FRAP values. The galacto-oligosaccharides and xylo-oligosaccharides lowered the malondialdehyde levels in the diabetic rats (p < 0.05). The galacto-oligosaccharides decreased the serum levels of 8-hydroxy-2'-deoxyguanosine (p = 0.01), while the xylo-oligosaccharides increased the FRAP (p < 0.05) in the experimental animals. None of the oligosaccharides affected triacylglycerol and interleukin-6 concentrations, but the galacto-oligosaccharides decreased the TC and CRP levels in the diabetic animals. Both oligosaccharides exert a beneficial effect on the antioxidant protection of the diabetic rats, but have a minor effect on their lipid and inflammatory profiles.

The effect of flutamide on the physical working capacity and activity of some of the key enzymes for the energy supply in adult rats.

The aim of the study was to assess the effects of androgen receptor antagonists on the physical working capacity and activity of some of the key muscle enzymes for the energy supply in rats. Young adult male Wistar rats were divided into two groups. One group received 15 mg kg-1 of flutamide daily for 6 days a week and the other group served as control for 8 weeks. At the beginning and at the end of the experiment, all rats were subjected to submaximal running endurance (SRE), maximum time to exhaustion (MTE), and maximal sprinting speed (MSS) tests. At the end of the trial, maximum oxygen consumption (VO2max) test was performed and the levels of testosterone, erythrocytes, hemoglobin as well as enzyme activity of succinate dehydrogenase (SDH), lactate dehydrogenase (LDH), and NAD.H2-cytochrome-c reductase (NAD.H2) of the gastrocnemius muscle were measured. Serum testosterone of the flutamide-treated rats was higher than that of the controls, which verifies the effectiveness of the dose chosen. MTE and SRE of the anti-androgen-treated group were lower compared with the initial values. Flutamide treatment decreased the activity of SDH and NAD.H2 compared with the controls. We found no effect of the anti-androgen treatment on MSS, VO2max, running economy, LDH activity, and hematological variables. Our findings indicate that the maintenance of the submaximal and maximal running endurance as well as the activity of some of the key enzymes associated with muscle oxidative capacity is connected with androgen effects mediated by androgen receptors.

Bcl-2/Bax ratio, mitochondrial membranes and aerobic enzyme activity in cardiomyocytes of rats after submaximal training.

INTRODUCTION: Mitochondria are an active and continuous source of reactive oxygen species (ROS) during respiration. The ROS increased production during endurance training is a result of an augmented electron transport through the respiratory chains, making in this way the mitochondria a potential target for oxidative damage. The Bcl-2 protein family plays a central role in the transition of apoptotic signals towards the mitochondria in stress-induced apoptosis. AIM: The present work studied the effect of endurance training on the expression of the apoptotic proteins Bcl-2 and Bax in rat cardiomyocytes, as well as the concomitant changes in the ultrastructure of the mitochondria and activity of some enzymes residing there. MATERIAL AND METHODS: Two groups of male Wistar rats were used. One was the control and the other was trained on treadmill with submaximal loading for eight weeks. At the end of the trial, samples of the myocardium of all the experimental animals were obtained. Immunohistochemical reactions for Bcl-2 and Bax and enzymehistochemical reactions for succinate dehydrogenase and NADH2-cytochrome C-reductase were done. The results were analyzed using specialized software. Transmission electron microscopical study was carried out too. RESULTS: In the myocardium of the trained animals the expression of Bcl-2 and Bcl-2/Bax ratio were significantly higher compared to the controls. The mitochondria had intact outer and inner membranes, with no signs of swelling. Mitochondria with denser packed cristae were found predominantly. No significant differences were found in the activity of the investigated enzymes in the cardiomyocytes of the animals from both groups. CONCLUSIONS: In the myocardium of the experimental animals endurance training for eight weeks does not lead to activation of apoptotic processes via the mitochondrial pathway. This type of exercise training could be used for cardioprotection in order to elevate apoptotic threshold of cardiomyocytes.

ATP and LPL histochemical activity of rat cardiomyocytes and adipocytes treated with androgenic anabolic steroids.

AIM: To study the effect of short-term and long-term treatment with retabolil, an androgenic anabolic steroid, on the activity of the enzymes ATP and LPL in rat cardiomyocytes and adipocytes. MATERIAL AND METHODS: Six male Wistar rats (mean weight 195-200 g.) were given retabolil 50 mg/kg once subcutaneously, another six were treated with retabolil at the same dose subcutaneously once a week for 6 weeks and another six were used as controls treating them with physiological saline in the same way. After six weeks the animals were sacrificed. Fragments of the left ventricle of the heart and of the subcutaneous tissue from the gluteal region were resected and enzyme-histochemical reactions for ATP and LPL were performed on fresh cryostat sections. RESULTS: The cardiomyocytes of the rats treated only once with retabolil showed no changes in the ATP and LPL activity in comparison with the controls. In the rats given a long-term treatment with retabolil, the enzyme-histochemical reaction for ATP was better expressed while that for LPL was weak. The subcutaneous adipose tissue of the long-term retabolil-treated animals contained some adipocytes that expressed positive LPL and ATP activity. CONCLUSIONS: Our data suggest that androgenic anabolic steroids exert an effect on the activity of the enzymes ATP and LPL in rat cardiomyocytes and adipocytes which depends on the duration of treatment.

Effects of submaximal training and anabolic androgenic steroids administration on steroidogenic enzyme activity in rat Leydig cells.

The purpose of the present study was to investigate the single and combined effects of submaximal training and anabolic androgenic steroids (AAS) treatment on the activity of 3beta hydroxysteroid dehydrogenase (3betaHSD) in rat Leydig cells (LC). Forty male Wistar rats were distributed into 4 groups. Half of them exercised on treadmill. After 2 weeks half of the trained and sedentary rats received weekly either 10 mg x kg(-1) Nandrolone Decanoate (ND) or Placebo (Pl) i.m. for 6 weeks. The day after the last exercises all the groups: 1) sedentary + Pl (SP); 2) sedentary + ND (SND); 3) trained + Pl (TP) and 4) trained + ND (TND) were decapitated. On fresh cryostat sections of the testes of each animal enzymehistochemical reaction for the activity of 3betaHSD was carried out. Our results demonstrate that in sedentary rats ND treatment decreased the activity of 3betaHSD in the LC in comparison to SP. Endurance training also decreased the activity of 3betaHSD in TP group compared to SP. On sections of the testes of group TND a pronounced reduction in the enzyme activities of 3betaHSD in the LC was found in comparison with the other groups. In conclusion we suggest that submaximal endurance training and/or administration of AAS downregulate the steroidogenic enzyme activity of rat Leydig cells.