Difference in effect of atrial natriuretic peptide on cGMP in aortic and coronary smooth muscle cells.
Blood vessels show a heterogeneous response to the atrial natriuretic peptide (ANP). In our experiments thoracic aorta from the guinea pig relaxed in response to atriopeptin III (AP; rat ANP-103-126) and to sodium nitroprusside (SNP). In contrast, in perfused guinea pig hearts, AP III produced no change in coronary flow, while SNP increased flow. In smooth muscle cells cultured from the coronary system (CASM) and from the thoracic aorta (TASM), we compared receptor binding and the effects on guanosine 3',5'-cyclic monophosphate (cGMP) production of AP III. AP III bound specifically with equal affinity and with equivalent numbers of binding sites in both cell types. AP III produced a dose-dependent increase in cGMP in TASM (50% effective concentration approximately 3 nM) with a maximum 11-fold increase over basal at 1 microM AP III. In contrast, in CASM, AP III failed to increase cGMP. Nitroprusside increased cGMP in both cell types. Autoradiograms of 125I-labeled AP III linked to cell membranes showed bands at 70 kDa (ANP-C receptor) in both cell types. A second band at 140 kDa (ANP-B receptor) was only seen in TASM. These results suggest that smooth muscle cells of coronary resistance vessels of the guinea pig do not express the particulate guanylyl cyclase that is activated by ANP.
Newman
W H
WH
Department of Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston 29425.
Kato
J
J
Becker
B F
BF
Currie
M G
MG
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002478:Cells, Cultured; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000166:cytology / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism
D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP