چكيده لاتين :
Leptin affects paraventricular nucleus of hypothalamus and reduces appetite while
activation of ل2-adrenoceptors at this site has opposite action. The reducing effect of ل2-adrenoceptors
inhibition on body weight and appetite and also enhancing effects on lipolysis, sympathetic activation
and plasma insulin levels in animals have been reported. We studied the effect of yohimbine treatment
(2 mg/kg/day orally) as ل2-adrenoceptor antagonist on plasma levels of leptin, insulin and glucose and
also body weight in rats. Five normal yohimbine treated, five diabetic insulin treated (10 u/kg/day) and
five diabetic insulin (l0 u/kg/day) and yohimbine (2 mg/kg/day) treated male Sprague Dawley rats were
used and treatment continued for six days. One blood sample before treatment and three blood samples
after treatment (with one day interval) were collected from all rats. Our results showed statistically
significant increase in leptin (P < 0.037) and insulin (P < 0.042) and decrease in body weight (P <
0.004) in normal yohimbine treated rats. In diabetic rats insulin levels before and after treatment were
similar in two groups but leptin, glucose and body weight were significantly reduced in yohimbine and
insulin treated compared with just insulin treated rats. The present results indicate that yohimbine
treatment can reduce body weight by increasing stimulation of lipolysis and increasing plasma levels of
leptin. This plasma leptin enhancement in normal rats may be contributed to the weight reducing effect
of ل2-receptor antagonist drugs. Our study introduces the ل2-receptor antagonists as body weight
reducing, glucose restoring and insulin and leptin increasing drugs.
