Effect of isoproterenol on the isolated pregnant rat myometrium.
In pregnant rat myometrium, isoproterenol (10(-8) M) inhibited spontaneous contractions without causing hyperpolarization. Isoproterenol (10(-6) M) relaxed the depolarized muscle without affecting the membrane potential. The presence of 80 mM Na+ did not affect the degree of high-K+ depolarization. It was also without any influence on the effects of isoproterenol on the depolarized uterus. The results are consistent with the concept that hyperpolarization is not a prerequisite for beta-adrenoceptor induced relaxation of uterine smooth muscle.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects*
D007545:Isoproterenol; D011188:Potassium