Effects of prostaglandins on rat cardiac adenylate cyclase.
A significant stimulatory action of PGE1 on adenylate cyclase of the particulate membrane preparation of rat heart was observed at 1 X 10(-4) M. PGE1 caused a positive inotropic effect on isolated spontaneously beating rat atria 1 X (10(-5) M, and an increase in atrial  cyclic AMP level at 1 X 10(-6) M. PGE2 stimulated the atrial but not the whole heart particulate adenylate cyclase. PGF 2alpha had no effect on these enzyme preparations. Our results suggest that: (i) The inotropic response of isolated spontaneously beating rat atria to PGE1 may be connected with an increase in cyclic AMP level; (ii) the effect of prostaglandins on heart in vivo must be indirect, because the concentrations needed to stimulate isolated atria and particulate adenylate cyclase were high, compared with the doses effective in vivo.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000201:enzymology; D011458:Prostaglandins E / Q000494:pharmacology*; D011460:Prostaglandins F / Q000494:pharmacology*; D051381:Rats; D013268:Stimulation, Chemical
D011458:Prostaglandins E; D011460:Prostaglandins F; D000262:Adenylyl Cyclases