Effect of yohimbine on urethane-induced hyperglycemia in rats.
Urethane is a widely used anesthetic and yohimbine is a well-known alpha 2-adrenergic antagonist. In fasted Wistar rats urethane at an anesthetic dose (1.25 g/kg, i.p.) caused an increase in plasma glucose, while pentobarbital at an anesthetic dose (40 mg/kg, i.p.) did not. Urethane caused no change in plasma glucose in adrenalectomized rats. The hyperglycemic effect of urethane was not inhibited by pretreatment with propranolol (1 mg/kg, p.o.) or prazosin (10 mg/kg, p.o.), but was reduced by pretreatment with phentolamine (10 mg/kg, p.o.) or yohimbine (10 mg/kg, p.o.). Urethane caused an elevation of plasma adrenaline, and yohimbine reduced the elevation. In addition, the pretreatment of yohimbine potentiated the urethane-induced increase in plasma insulin. These results indicate that yohimbine may inhibit the urethane-induced hyperglycemia that is mediated by the central and peripheral alpha 2-adrenergic systems.
Aisaka
K
K
Suntory Institute for Biomedical Research, Osaka, Japan.
Kihara
T
T
Koike
M
M
Kuroki
M
M
Ishihara
T
T
D000818:Animals; D005905:Glyburide / Q000494:pharmacology; D006943:Hyperglycemia / Q000097:blood / Q000139:chemically induced*; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014520:Urethane / Q000494:pharmacology*; D015016:Yohimbine / Q000494:pharmacology*
D015016:Yohimbine; D014520:Urethane; D005905:Glyburide; D011224:Prazosin; D010646:Phentolamine