This work was conducted to investigate the effect of glimepiride on
the brain chemical neurotransmitters norepinephrine (NE), serotonine (5-
HT), gamma-aminobutyric acid (GABA) and dopamine (DA) in different
brain areas namely cerebral cortex (C.C.), thalamus/ hypothalamus (TH),
midbrain (M.B.) and cerebellum (C.) in streptozotocin (STZ) induced
diabetes and to study the effect of Vit E separately and concomitantly with
glimepiride on the previous neurotransmitters.
In diabetes induced experimentally in rats by streptozotocin (STZ)
(50 mg/kg I.P) results of the present work showed significant elevation of
NE level (P < 0.05) in CC, TH, and GABA in all tested brain areas and
significant reduction of DA and 5HT levels (P<0.05) in all tested brain areas
compared with normal rats. In diabetic group treated with glimepiride (0.1
mg/kg orally), results of the present work showed significant elevation of
GABA levels, reduction of DA levels (P<0.05) in all tested brain areas. In
diabetic rats treated with Vit, E (0.1 mg/kg orally) there were non
significant changes (P >0.05) of GABA, DA, NE and 5HT levels (P > 0.05)
in all tested brain areas compared with diabetic non treated rats.
Concomitant administrations of glimepiride (0.1 mg/kg orally) and Vit. E
(0.1 mg/kg orally) showed significant reduction of GABA, significant
elevation of 5HT levels (P<0.05) in all tested brain areas with significant
reduction of NE level (P<0.05) in CC, TH.In conclusion: Diabetes may induce brain damage due to oxidative
stress and hyperglycemia by disturbing the turnover rate of monoamines and
GABA, glimepiride minimize these brain effects, moreover,
coadministration •of Vit. E and glimepiride correct hypergleyemia and
increase brain protection against hyperglycemia by correcting the disturbed
turnover rate of monoamines and GABA. |
