Efeitos do treinamento aeróbio sobre sinais precoces do remodelamento do ventrículo esquerdo induzido pelo diabetes Mellitus experimental

Our aim was to investigate the effects of an aerobic training program on adverse and early left ventricle (LV) remodeling, using an experimental model of short-term type 1 diabetes (T1D). Wistar rats were divided in 4 groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). T1D was induced by streptozotocin (45 mg/kg). The training program consisted of 4 weeks running on a treadmill (13 m/min, 60 min/day, 5 days/week). At the end of the experiments, hearts were collected for analysis of morphology and transcriptional profile of LV, by focusing on its remodeling. Deaths were recorded during the 4-week period. We verified high mortality among animals of DS group, whereas it was significantly reduced in DT group. DS group also showed an increase in cross-sectional area of cardiomyocytes and fibrosis. TD group exhibited reduction in measures of cardiac trophism, but with respect to collagen content, it was similar to CS group. Analysis of gene expression related to cardiac remodeling revealed decreased expression of collagen I and III, as well as low expression of MMP-2 in DS group. TD group showed decreased levels of mRNA for MMP-9, and unchanged gene expression of MMP-2 when compared with the CS group. The expression of MMP-2 and TGF-1 were increased in CT group. The ratio between gene expression of collagen I and III was increased in the CT group and decreased in diabetic groups. These results establish early changes of the structure and transcriptional profile of LV myocardium. Moreover, they indicate that aerobic exercise training plays specific protection against mechanisms responsible for cardiac damage observed in T1D

O efeito da dessincronização circadiana sobre o metabolismo

The lost of phase relationship between rhythms and behaviour can, and often do, undesirable consequences. The purpose os study was to ascertain the effect of circadian desynchronization in T22 about metabolism of wistar rats. The subjects consisted of 24 animals separated in two groups: control (n=12) T24 with 8 weeks of aged and experimental group (n=12) T22, also with 8 weeks of aged. Both the groups were subject to register of locomotor actitivity, body temperature, body weight and food intake in all the experiment. And more, both the groups were subject to food deprivation, running in treadmill and forced swimming. The results show rhythm of locomotor activity and body temperature desynchronized. Dont exist diference in body weight between both the groups (T24 = 386,75±40,78g e T22 380,83±44,28g) . However, the food intake was different between the phases, light and dark, in intergroup and intragroup. The body temperature was not different in food deprivation. The same ocurred for running in treadmill and forced swimming. Since similar alterations occur in shift workers, it is proposed that the experimental paradigm presented in this manuscript is a useful model of shift work. That is, alterations in activity/rest cycles and consummatory behavior can affect the health of organism