Inhibitory effect of [Tyr34]bPTH-(7-34)-amide on bPTH-(1-34) ability to reduce uterine contraction.
Synthetic bovine parathyroid hormone containing the 1-34 NH2-terminal amino acids [bPTH-(1-34)] inhibits uterine contraction stimulated by a variety of agonists. Previously, we reported that the parathyroid hormone analogue [Nle8, Nle18, Tyr34]bPTH-(3-34)amide [NTA-(3-34)] antagonized this effect of bPTH-(1-34) while the analogue [Tyr34]bPTH-(7-34)amide [bPTH-(7-34)] used in this study stimulated uterine contraction. However, contrary to this previous report, bPTH-(7-34) in the present study failed to initiate a contractile response and instead resulted in an inhibitory response to the bPTH-(1-34) effect on uterine contraction in a dose-related manner. The inhibitory response of bPTH-(7-34) was further confirmed by demonstrating that this preparation of bPTH-(7-34) was capable of blocking bPTH-(1-34)-stimulated adenylate cyclase activity on particulate fractions of osteoblast-like cells from neonatal mouse calvarial. These results are consistent with those in the literature for the antagonistic effect of the 7-34 PTH fragment.
Shew
R L
RL
Department of Anatomical Sciences, Oklahoma University Health Sciences Center, Oklahoma City.
Robinson
M F
MF
Olansky
L
L
Yee
J A
JA
D000109:Acetylcholine / Q000502:physiology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014590:Uterine Contraction / Q000187:drug effects*
D010281:Parathyroid Hormone; D010446:Peptide Fragments; C058350:parathyroid hormone (7-34); C025076:parathyroid hormone (1-34), bovine; C038040:parathyroid hormone (7-34)amide, Tyr(34)-; D000262:Adenylyl Cyclases; D000109:Acetylcholine