M. Takita et al., EFFECTS OF BEVANTOLOL HCL ON IMMOBILIZATION STRESS-INDUCED HYPERTENSION AND CENTRAL BETA-ADRENOCEPTORS IN RATS, Pharmacology, biochemistry and behavior, 45(3), 1993, pp. 623-627
Effects of chronic treatment with bevantolol, a beta-adrenoceptor bloc
ker, and of repeated immobilization stress on blood pressure, body wei
ght, and [H-3]dihydroalprenolol ([H-3]DHA) binding to the cerebral cor
tex were examined in rats. Systolic blood pressure increased to approx
imately 150 mmHg when stress was applied for 14 days (2 h day-1). This
increase was inhibited by chronic treatment with bevantolol (250 mg k
g-1 daily). However, bevantolol did not suppress the inhibition of bod
y weight gain by stress. The maximum number of [H-3]DHA binding sites
(B(max)) in the cerebral cortex was decreased by stress without changi
ng the affinity, and the decrease in B(max) mainly reflected the reduc
tion of beta1-adrenoceptors. Bevantolol treatment (250 mg kg-1) increa
sed the B(max) to 137% and completely inhibited the downregulation of
beta-adrenoceptors by stress. These results show that bevantolol can i
nhibit both the hypertension and downregulation of the central beta1-a
drenoceptors induced by stress.