Atypical beta-adrenoceptors mediate isoprenaline induced vasodilatation in the rabbit uterine vascular bed
Oriowo, M.A.
African Journal of Medicine and Medical Sciences 27(1-2): 123-127
1998
ISSN/ISBN: 0309-3913 PMID: 10456144 Document Number: 487265
beta-Adrenoceptor subtype(s) mediating isoprenaline-induced vasodilator responses in the perfused rabbit uterine vascular bed was characterized. Isoprenaline induced dose-dependent reduction in perfusion pressure with -logED50 value of 5.8 +/- 0.1. Propranolol (10(-6) M) had little or no effect on isoprenaline-induced vasodilatation. Similarly, cyanopindolol (10(-6) M) did not antagonize the vasodilator response. CGP 12177, an agonist on beta 3- or beta 2- adrenoceptor mediated responses. The results would indicate that isoproterenol-induced vasodilation in the perfused rabbit (oestrus or pregnant) uterine vascular bed was mediated by atypical beta-adrenoceptors which may not be identical with those in adipose tissues or gastro-intestinal tract. In addition, the fact that pregnancy did not enhance isoprenaline-induced vasodilation would suggest that these receptors may not be involved in the hyperaemia of pregnancy.