Inhibition of the in vivo parathyroid hormone-mediated calcemic response in rats by a synthetic hormone antagonist.
The parathyroid hormone (PTH) analog, [Tyr34]bovine PTH-(7-34)-amide, can inhibit the PTH-mediated elevation of plasma calcium in thyroparathyroidectomized rats in vivo. The analog is devoid of PTH-like agonist activity in this system. Repeated doses of analog inhibit the animal's calcemic response to PTH. The elevation in serum calcium levels mediated by PTH in this assay reflects PTH action (calcium mobilization) on bone. Earlier studies demonstrated antagonist properties of the analog in a renal-based assay; PTH-stimulated increases in urinary phosphate and cyclic AMP excretion were completely inhibited by the synthetic analog. Along with previous studies, this report indicates that [Tyr34]bovine PTH-(7-34)-amide is an effective in vivo antagonist for several major parameters of PTH action in both kidney and bone.
Doppelt
S H
SH
Neer
R M
RM
Nussbaum
S R
SR
Federico
P
P
Potts
J T
JT
Rosenblatt
M
M
D000818:Animals; D001681:Biological Assay; D002118:Calcium / Q000097:blood / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D010281:Parathyroid Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
D006728:Hormones; D010281:Parathyroid Hormone; D010446:Peptide Fragments; C038040:parathyroid hormone (7-34)amide, Tyr(34)-; D002118:Calcium