title: The hormonal control of adenylate cyclase in rabbit myometrium: in vitro inhibition by adenosine and lack of effect of progesterone.
abstract: The mechanism by which progesterone modifies uterine smooth muscle cell contraction is still unknown. We investigated the biochemical basis of progesterone effects on myometrium of estradiol-primed rabbits. Progesterone did not affect adenylate cyclase basal activity and displayed no interaction with stimulators of myometrium adenylate cyclase (NaF, guanylyl nucleotides, beta-adrenoreceptor agonists, prostaglandins, forskolin) or with adenosine. On the other hand, adenosine inhibited myometrial adenylate cyclase, which correlates with its contracting properties in vivo; this inhibition is mediated through interaction at 'P sites'. We conclude that whilst adenosine inhibits myometrial adenylate cyclase by acting at 'P sites', progesterone does not interact directly with adenylate cyclase to regulate myometrial contractility.
mesh_terms: D000241:Adenosine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D005260:Female; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D009215:Myometrium / Q000201:enzymology*; D011374:Progesterone / Q000494:pharmacology*; D011817:Rabbits; D014590:Uterine Contraction / Q000187:drug effects
chemical_list: D006165:Guanylyl Imidodiphosphate; D011374:Progesterone; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000262:Adenylyl Cyclases; D000241:Adenosine