Exercise training prevents hyperinsulinemia, muscular glycogen loss and muscle atrophy induced by dexamethasone treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exercise training attenuates acute hyperalgesia in streptozotocin-induced diabetic female rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Erythropoietin Attenuates Apoptosis After Ischemia-Reperfusion-Induced Renal Injury in Transiently Hyperglycemic Wister Rats

Background. Hyperglycemia is associated with a decreased tolerance to ischemia and an increased severity of renal ischemia reperfusion (I/R) injury. It has been suggested that erythropoietin (EPO) attenuates this effect in normoglycemic animals. This study sought to examine the effects of EPO on treatment renal I/R injury (IRI) in transiently hyperglycemic rats.Material and Methods. Twenty-eight male Wister rats anesthetized with isoflurane received glucose (2.5 g.kg(-1) intraperitoneally) before right nephrectomy. They were randomly assigned to four groups: sham operation (S); IRI (ISO); IRI+EPO, (600 UI kg(-1) low-dose EPO [EL]); and IRI+EPO 5000 UI kg(-1) (high-dose EPO [EH]). IRI was induced by a 25-minute period of left renal ischemia followed by reperfusion for 24 hours. Serum Creatinine and glucose levels were measure at baseline (M1), immediately after the ischemic period (M2), and at 24 hours after reperfusion (M3). After sacrificing the animals, left kidney specimens were submitted for histological analysis including flow cytometry to estimate tubular necrosis and the percentages of apoptotic, dead or intact cells.Results. Scr in the ISO group was significantly higher at M3 than among the other groups. Percentages of early apoptotic cells in ISO group were significantly higher than the other groups. Percentages of late apoptotic cells in S and ISO groups were significantly greater than EL and EH groups. However, no significant intergroup differences were observed regarding the incidence of tubular necrosis.Conclusions. Our results suggested that, although not preventing the occurrence of tubular necrosis, EPO attenuated apoptosis and glomerular functional impairment among transiently hyperglycemic rats undergoing an ischemia/reperfusion insult.

Exercise preconditioning modulates genotoxicity induced by doxorubicin in multiple organs of rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inflammation and apoptosis induced by mastoparan Polybia-MPII on skeletal muscle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Acute exercise reverses aged-induced impairments in insulin signaling in rodent skeletal muscle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

5-AMINOLEVULINIC ACID-INDUCED ALTERATIONS OF OXIDATIVE-METABOLISM IN SEDENTARY AND EXERCISE-TRAINED RATS

5-Aminolevulinic acid (ALA), a heme precursor that accumulates in acute intermittent porphyria patients and lead-exposed individuals, has previously been shown to autoxidize with generation of reactive oxygen species and to cause in vitro oxidative damage to rat liver mitochondria. We now demonstrate that chronically ALA-treated rats (40 mg/kg body wt every 2 days for 15 days) exhibit decreased mitochondrial enzymatic activities (superoxide dismutase, citrate synthase) in liver and soleus (type I, red) and gastrocnemius (type IIb, white) muscle fibers. Previous adaptation of rats to endurance exercise, indicated by augmented (cytosolic) CuZn-superoxide dismutase (SOD) and (mitochondrial) Mn-SOD activities in several organs, does not protect the animals against liver and soleus mitochondrial damage promoted by intraperitoneal injections of ALA. This is suggested by loss of citrate synthase and Mn-SOD activities and elevation of serum lactate levels, concomitant to decreased glycogen content in soleus and the red portion of gastrocnemius (type IIa) fibers of both sedentary and swimming-trained ALA-treated rats. In parallel, the type IIb gastrocnemius fibers, which are known to obtain energy mainly by glycolysis, do not undergo these biochemical changes. Consistently, ALA-treated rats under swimming training reach fatigue significantly earlier than the control group. These results indicate that ALA may be an important prooxidant in vivo.

Is gender crucial for cardiovascular adjustments induced by exercise training in female spontaneously hypertensive rats?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cimetidine-induced vascular cell apoptosis impairs testicular microvasculature in adult rats

Cimetidine, an H2 receptor antagonist used for treatment of gastric ulcers, exerts antiandrogenic and antiangiogenic effects. In the testes cimetidine impairs spermatogenesis, Sertoli cells and peritubular tissue, inducing apoptosis in the myoid cells. Regarding the importance of histamine and androgens for vascular maintenance, the effect of cimetidine on the structural integrity of the testicular vasculature was evaluated. Adult male rats received cimetidine (CMTG) and saline (CG) for 50 days. The testes were fixed in buffered 4% formaldehyde and embedded in historesin and paraffin. In the PAS-stained sections, the microvascular density (MVD) and the vascular luminal area (VLA) were obtained. TUNEL method was performed for detection of cell death. Testicular fragments embedded in Araldite were analyzed under transmission electron microscopy. A significant decrease in the MVD and VLA and a high number of collapsed blood vessel profiles were observed in CMTG. Endothelial cells and vascular muscle cells were TUNEL-positive and showed ultrastructural features of apoptosis. These results indicate that cimetidine induces apoptosis in vascular cells, leading to testicular vascular atrophy. A possible antagonist effect of cimetidine on the H2 receptors and/or androgen receptors in the vascular cells may be responsible for the impairment of the testicular microvasculature.

Role of Exercise Training on Autonomic Changes and Inflammatory Profile Induced by Myocardial Infarction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cardiac autonomic responses induced by a single bout of exercise with flexible pole

Background: Flexible poles are tools used to provide rapid eccentric and concentric muscle contractions. It lacks in the literature studies that analyze acute cardiovascular responses in different exercises performed with this instrument. It was investigated the acute effects of exercise with flexible poles on heart period in healthy women. Methods: The study was performed on 32 women between 18 and 25 years old. It was evaluated the heart rate variability (HRV) in the time (SDNN, RMSSD and pNN50) and frequency domain (HF, LF and LF/HF ratio). The subjects remained at rest for 10 minutes. After the rest period, the volunteers performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 60 minutes and HRV were analyzed. Results: It was observed no significance changes in the time domain (SDNN: p = 0.14; RMSSD: p = 0.8 and pNN50: p = 0.86) and frequency domain indices (LF (nu): 0.4; LF (ms2): p = 0.34; HF (nu): p = 0.4; HF (ms2): p = 0.8 and LF/HF ratio: p = 0.3) between before and after single bout of exercise with flexible pole. Conclusion: A single bout of exercise with flexible pole did not significantly change cardiac autonomic regulation in healthy women.

Effects of Physical Exercise on the P38MAPK/REDD1/14-3-3 Pathways in the Myocardium of Diet-Induced Obesity Rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aerobic Exercise Training Prevents Heart Failure-Induced Skeletal Muscle Atrophy by Anti-Catabolic, but Not Anabolic Actions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)