Effects of 17 beta-estradiol and progesterone on agonist-stimulated inositol phospholipid breakdown in uterine smooth muscle.
Inositol phospholipid breakdown, from a [3H]inositol-labelled pool, induced by a variety of contractile agents was monitored in uterine smooth muscle slices pretreated with estradiol-17 beta or estradiol-17 beta and progesterone by measuring the accumulation of [3H]inositol phosphates. Agonist potencies for stimulating [3H]IP accumulation were not affected by hormone treatment but the maximum responses were dependent upon hormonal state. Maximum responses to carbachol, norepinephrine, prostaglandin F2 alpha were increased in progesterone-dominated tissues but maximum responses to oxytocin were unaffected. Inhibition of agonist-induced responses by competitive receptor antagonists confirmed the receptor specificity of carbachol-, norepinephrine- and oxytocin-mediated responses. Partial membrane depolarization (25 mM K+) did not affect agonist-induced maximal responses in either estrogen- or progesterone-dominated tissue. These data suggest that gonadal steroid hormones affect agonist-dependent intracellular calcium mobilization processes.
Ruzycky
A L
AL
Department of Biochemical Pharmacology, School of Pharmacy, State University of New York, Buffalo 14260.
Triggle
D J
DJ
D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism*; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D013403:Sugar Phosphates / Q000378:metabolism*; D014590:Uterine Contraction / Q000187:drug effects
D007295:Inositol Phosphates; D013403:Sugar Phosphates; D011374:Progesterone; D004958:Estradiol