The cardiac effects of parathyroid hormone in the tiger frog, Rana tigrina.
1. The cardiac effects of the N-terminal (1-34) peptide fragment of bovine parathyroid hormone [bPTH-(1-34)] on isolated atria were examined in the frog, Rana tigrina. 2. bPTH-(1-34) produced dose-related inotropic response but no chronotropic response. This inotropic response varied at different times of the year. 3. The inotropic effect of bPTH-(1-34) was attenuated in the presence of verapamil and imidazole. 4. The mechanism of action of bPTH-(1-34) is probably a stimulation of calcium influx directly or indirectly via cAMP production.
Chiu
K W
KW
Department of Biology, Chinese University of Hong Kong, Shatin, N.T.
Lee
Y C
YC
Pang
P K
PK
D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011898:Ranidae / Q000502:physiology*
D002316:Cardiotonic Agents; D010281:Parathyroid Hormone; D010446:Peptide Fragments; C025076:parathyroid hormone (1-34), bovine