Effects of bevantolol HCl on immobilization stress-induced hypertension and central beta-adrenoceptors in rats.
Effects of chronic treatment with bevantolol, a beta-adrenoceptor blocker, and of repeated immobilization stress on blood pressure, body weight, and [3H]dihydroalprenolol ([3H]DHA) binding to the cerebral cortex were examined in rats. Systolic blood pressure increased to approximately 150 mmHg when stress was applied for 14 days (2 h day-1). This increase was inhibited by chronic treatment with bevantolol (250 mg kg-1 daily). However, bevantolol did not suppress the inhibition of body weight gain by stress. The maximum number of [3H]DHA binding sites (Bmax) in the cerebral cortex was decreased by stress without changing the affinity, and the decrease in Bmax mainly reflected the reduction of beta 1-adrenoceptors. Bevantolol treatment (250 mg kg-1) increased the Bmax to 137% and completely inhibited the downregulation of beta-adrenoceptors by stress. These results show that bevantolol can inhibit both the hypertension and downregulation of the central beta 1-adrenoceptors induced by stress.
Takita
M
M
Department of Pharmacology, Fukui Medical School, Japan.
Kigoshi
S
S
Muramatsu
I
I
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004082:Dihydroalprenolol; D015536:Down-Regulation / Q000187:drug effects; D004326:Drinking / Q000187:drug effects; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D007103:Immobilization; D008297:Male; D011412:Propanolamines / Q000097:blood / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C021148:bevantolol; D004082:Dihydroalprenolol; C025716:ICI 89406