Physical exercises have been recommended in the prevention of
non-insulin dependent diabetes mellitus (
NIDDM), but the mechanisms involved in this intervention are not yet fully understood. Experimental models offer the opportunity for the study of this matter. The present study was designed to analyze the diabetes evolution in rats submitted to neonatal treatment with
alloxan with the objective of verifying the suitability of the model to future studies with exercises. For this, newly born rats (6 days old) received intraperitoneal
alloxan (A=200 mg/kg of
body weight). Rats injected with vehicle (
citrate buffer) were used as controls (C). The fasting
blood glucose level (mg/dL) was higher in the
alloxan group at the day 28 (C=47.25 +/- 5.08; A=54.51 +/- 7.03) but not at the 60 day of age (C=69.18 +/- 8.31; A=66.81 +/- 6.08). The
alloxan group presented higher
blood glucose level during
glucose tolerance test (GTT) (mg/dL. 120 min) in relation to the control group both at day 28 (C=16908.9 +/- 1078.8; A=21737.7 +/- 1106.4) and at day 60 (C=11463.45 +/- 655.30; A=15282.21 +/- 1221.84). Insulinaemia during GTT (ng/mL. 120 min) was lower at day 28 (C=158.67 +/- 33.34; A=123.90 +/- 19.80), but presented no difference at day 60 (C=118.83 +/- 26.02; A=97.88 +/- 10.88). At day 60, the
glycogen concentration in the soleus muscle (mg/100 mg) was lower in the
alloxan group (0.3 +/- 0.13) in relation to the control group (0.5 +/- 0.07). No difference was observed between groups in relation to (micromol/g.h):
Glucose Uptake (C=5.8 +/- 0.63; A=5.2 +/- 0.73);
Glucose Oxidation (C=4.3 +/- 1.13; A=3.9 +/- 0.44);
Glycogen Synthesis (C=0.8 +/- 0.18; A=0.7 +/- 0.18) and
Lactate Production (C=3.8 +/- 0.8; A=3.8 +/- 0.7) by the isolated soleus muscle. The
glucose-stimulated insulin secretion (16.7mM) by the isolated islets (ng/5 islets. h) of the
alloxan group was lower (14.3 +/- 4.7) than the control group (32.0 +/- 7.9). Thus, we may conclude that this neonatal diabetes induction model gathers interesting characteristics and may be useful for further studies on the role of the exercise in the
diabetes mellitus appearance.