The present study was designed to investigate whether short-term early
diabetes mellitus alters the activity of the adrenal cortex and medulla in
response to exercise. Thirty male albino rats were used as a control group,
another thirty rats were used for induction of diabetes mellitus liv
intravenous injection of 65 mg/kg streptrozotocin. A swimming exercise
was done in a swimming pool for 15 minutes. The control and diabetic
groups were subdivided into 3 subgroups each included 10 rats: preswimming,
immediately after swimming and post-swimming subgroups.
The diabetic rats were subjected to exercise experiment 15 days after
induction of diabetes. Blood samples were taken before swimming,
immediately after the end of swimming and 20 minutes after the end of
swimming. The plasma samples were collected using heparin as
anticoagulant and EGTA as antioxidant, for determination of plasma
glucose, insulin, non-esterified fatty acids (NEFA), epinephrine,
norepinephrine and cortisol. Immediately after swimming exercise,
plasma insulin levels decreased significantly in controls (P < 0.001),
while plasma NEFA increased significantly not only in controls (P
0.001) but also in diabetic rats (P < 0.001) compared to pre-swimming
period. Immediately after swimming -exercise the increase in plasma
epinephrine and norepinephrine were non-significant in both control and
diabetic groups while there was a significant. increase in plasma cortisol
in both controls (P <0.001) and diabetics (P <0.001) immediately after
swimming compared to pre-swimming period. In addition, there was a
significant decrease in plasma cortisol in the diabetic rats compared to
controls immediately after swimming (P < 0.001) and in the postswimming
period (P < 0.001). It was concluded that, the short-term early
diabetes mellitus; when autonomic neuropathies are still absent; did not
affect the , activity of the adrenal medulla in response to exercise and did
not increase the activity of the adrenal cortex as in controls. The
exaggerated NEPA mobilization in the diabetic state was probably due to
reduced inhibition of lipolysis by the relative lack of insulin. |
