This study compares the effect of a calcium channel blocker
(amlodipine), an ACE inhibitor (fosinopril) and a BI-blocker
(atenolol) on blood glucose level, plasma insulin level, insulin
sensitivity and 24 hours urinary albumin excretion in groups of
rats made diabetic by a single intraperitoneal injection of
streptozotocin (STZ) (60 mg/kg).
Five groups of rats were used in this work. The first group
(control non-diabetic rats) was normoglycemic with blood glucose
level 116.8 ± 9.4 mg/di and 24 hour(H) urinary albumin
8.2 ± 1.2 mg/24 H urine.The other four groups were made diabetic
by a single dose of STZ. The second group (control nontreated
diabetic rats) exhibited hyperglycemia 8 weeks after
induction of diabetes with blood glucose level 354 ± 32.6 mg/
dl, plasma insulin level 10.1 ± 0.8 mill/nil and 24 11 urinary
albumin 42.6 ± 3.2 mg/24 H urine.
Results of this study revealed that amlodipine oral administration
in a dose of 5 mg/kg for 8 weeks in the third group of
STZ diabetic rats induced a significant reduction of blood, glucose
level (234 ± 18.6 versus 354 ± 32.6 in control diabetic
rats. Pc 0.05) and plasma insulin level (8.2 ± 0.6 mIll/m1 ver-
149
sus 10.1 t 0.8 mllEml in control diabetic rats, P<0.05). Amlodipine
also caused significant reduction in 24 H urinary albumin
(18.2 ± 1.2 mg versus 42.6 ± 3.2 mg in control diabetic
rats,P4).05) and significant improvement in sensitivity to intraperitoneal
bolus dose of insulin where it caused a significant
reduction in blood glucose level at OS H,1 H and 6 H after insulin
compared to control diabetic rats, P<0.05.
The results of this study also revealed that administration of
fosinopril in a dose of 5 mg/kg/day oral to the fourth group of
STZ diabetic rats for 8 weeks induced a significant reduction
in blood glucose level ,plasma insulin level, and 24 H urinary
albumin excretion compared to control non-treated diabetic
rats. Fosinopril, also produced a significant improvement in insulin
sensitivity at 0.5 H,1 H and 6 H after insulin injection
compared to control non-treated diabetic rats. In contrast, stenolol
given orally in a dose of 10 mg/kg/day for 8 weeks to fifth
group of diabetic rats did not induce a significant change in
blood glucose level ,plasma insulin level & 24 H urinary albumin
and even reduced insulin sensitivity compared to control
non-treated diabetic rats.
It could be concluded from these results that both amlodipine
and fosinopril are better antihypertensives than atenolol in
diabetic patients as they improved glucose tolerance and albuminuria
in STZ diabetic rats. |
