C. Le Page

Effect of physical exercise on adoptive experimental auto-immune encephalomyelitis in rats.

The aim of the study was to determine whether different programmes of exercise influence adoptive monophasic experimental auto-immune encephalomyelitis (adoptive EAE), a paralytic disease mediated by T-cells. Adoptive EAE was induced by the transfer of activated encephalitogenic T-lymphocytes into syngeneic recipients (Lewis rats, n = 85) and its development was followed by two independent observers. The results showed that 2 days of severe exercise (250 and 300 min) performed after the adoptive transfer of EAE slightly delayed the onset of the disease (P < 0.008) and the day of its maximal severity (P < 0.016) without affecting the overall severity of the disease. When this programme of exercise was performed before the cell transfer, it had no effect (P > 0.05). Two more moderate exercise programmes (5 × 120 min of running at constant speed or 5 × 60 min of running at variable speed, 5 consecutive days) performed between the adoptive transfer and the onset of the disease did not modify the development of the clinical signs of adoptive EAE (P >0.05). These results showed that severe exercise slightly influenced the effector phase of monophasic EAE and confirmed that physical exercise performed before the onset of experimental auto-immune diseases did not exacerbate the clinical signs.

Effect of moderate exercise on rat T-cells

SummaryThe aim of this study was a detailed examination of the effects of moderate exercise on T-cells in adult male Wistar rats. The T-cell populations were compared in sedentary rats (C, n = 5) and in rats trained for 4 weeks on a treadmill (30–60 min·day−1, 6 days·week−1, 20–30 m·min−1) and sacrificed at rest (Trest, n=5). In the T-rest rats, there were higher percentages of CD4+CD8−, CD4− CD8 + and CD4 − CD8 −thymocytes (P<0.05, P<0.05 and P<0.01 respectively) and of CD4−CD8 + splenocytes (P< 0.01), and a lower percentage of CD4−CD8+ cells in the lymph nodes (P<0.01). Compared with T-rest or C rats, trained rats (n = 5) or untrained rats (n = 5) sacrificed immediately after a running session (60 min, 30 m·min−1) had a higher percentage of mononucleated cells CD4 + CD8 -in the blood (P<0.05 and P<0.01). Lastly, compared with C rats, rats (n=5) sacrificed immediately after their 5th day of training (30–60 min·day−1) presented a higher total splenocyte population (P<0.05) and greater in vitro production of T-cell growth factor (interleukin 2 + interleucin 4) by splenocytes in response to a mitogen (P<0.01). These results would indicate that moderate endurance training modifies the cellular composition of lymphoid organs, without impairing the in vitro functions of T-cells.

Onset of exercise and diet program in obese women: metabolic and anorexigenic responses related to weight loss and physical capacities.

Perturbations of energy balance induce compensatory processes that may alter expected weight loss. In obese patients, our aim was to investigate the relationships that occurred between fasting plasma concentrations of anorexigenic peptides and metabolic parameters, appetite, physical capacity, and weight loss in the 5 first days of a program associating exercise and caloric reduction. Thirteen obese women were monitored from day 1 to day 5 with 2 exercise sessions in day 2 and day 4. We measured, in a fasted state, changes in body weight, hunger ratings, and plasma concentrations of fatty acids, triglycerides, leptin, insulin, amylin, peptide YY, and insulin-resistance index. Physical performance was assessed by a 6-min walking test. The program resulted in significantly reduced body weight (0.75±0.4 kg; p=0.001), of plasma concentrations of triglycerides, insulin, amylin, peptide YY, and the insulin-resistance index, and also increased fatty acids (p<0.05). Hunger ratings were increased (p<0.05). Program-induced changes in fatty acids, leptin, and insulin concentrations were related to physical performance (r(2)=0.45, 0.59, and 0.52; p<0.05, respectively) and to weight loss (r(2)=0.65, 0.57, 0.55; p<0.05, respectively). Five days of diet and exercise induced weight loss, improved lipid profile, and decreased insulin resistance while hunger ratings increased. Subjects with higher physical capacity lost more weight, presented higher increases in fatty acids and lower changes of leptin and insulin concentrations suggesting a better metabolic flexibility. To reduce the compensatory responses that can occur with energy imbalances, our study supports to account for individual activity level before prescribing weight-loss program associating diet and exercise.

Effects of glucocorticoid treatment on regenerating skeletal muscles in the rat

Summary Introduction. Regeneration of the soleus and extensor digitorum longus muscles of Wistar male rats was induced by an injection of snake venom (2 μ g, Notechis scutatus scutatus). Methods and results. Rats were treated for 14 to 16 days with dexamethasone (sub-cutaneous, 1 mg/kg on a daily basis) or not (control). Twenty five days after venom injection, the mass of the venom-treated extensor digitorum longus in dexamethasone rats was decreased when compared to control rats ( P P Conclusion. The results of this preliminary study suggest that dexamethasone treatment inhibits both the growth of extensor digitorum longus and the maturation of the soleus during regeneration.