Effect of parathyroid hormone and antagonist on aortic cAMP levels.
Experiments were designed to further investigate the vasoactive mechanisms of parathyroid hormone (PTH) on vascular smooth muscle cells. Time courses of the cAMP responses to the fragment (1-34) of bovine PTH (bPTH(1-34)) on cAMP levels have been studied in rat isolated aorta and in aortic myocytes in primary culture. In both aorta and myocytes bPTH (1-34) induced an increase in cAMP levels that was maximal and reached, respectively, 1.6- and 1.9-fold the basal level after 2 min of contact with bPTH (1-34). The effect of bPTH (1-34) on aortic cAMP content was concentration dependent in the range of 30-300 nM. (Nle8,18, Tyr34)-bPTH (3-34)amide, an antagonist of bPTH (1-34) with a stimulant effect on renal and vascular adenylate cyclase activity, inhibited the cAMP-increasing effect of bPTH (1-34). These results are in favour of a role for cAMP in the vasodilating effect of PTH.
Bergmann
C
C
Laboratoire de pharmacodynamie, INSERM U243, Faculté de pharmacie, Université Louis Pasteur, Strasbourg, France.
Schoeffter
P
P
Stoclet
J C
JC
Gairard
A
A
D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D011921:Rats, Inbred WKY; D019379:Teriparatide
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D019379:Teriparatide; C031617:parathyroid hormone (3-34); D004247:DNA; D000242:Cyclic AMP