Parathyroid hormone-related protein inhibits stimulated uterine contraction in vitro.
The effect of parathyroid hormone-related protein (PTHrP) fragments 1-34, 38-64, and 67-86 on acetylcholine-stimulated rat uterine contraction was examined in vitro. In addition, the possibility that PTHrP-(38-64) or (67-86) influenced relaxation caused by PTHrP-(1-34) was also investigated. Contraction of uterine horns was stimulated with 10(-6) or 10(-5) M acetylcholine. PTHrP-(1-34) reduced the magnitude of acetylcholine-stimulated uterine contraction. This effect was dose related over a concentration range of 10(-9)-10(-6) M. Neither PTHrP-(38-64) or PTHrP-(67-86) at concentrations of 10(-8)-10(-6) M affected uterine contraction stimulated by 10(-6) M acetylcholine. These fragments did not affect the relaxation caused by 10(-7) M PTHrP-(1-34). These results demonstrate that (1) PTHrP-(1-34) at 10(-6) M influences contraction of the rat myometrium and (2) the muscle relaxant activity of PTHrP is associated with the first 34 N-terminal amino acids.
Shew
R L
RL
Department of Anatomical Sciences, Oklahoma University Health Sciences Center, Oklahoma City.
Yee
J A
JA
Kliewer
D B
DB
Keflemariam
Y J
YJ
McNeill
D L
DL
D000109:Acetylcholine / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D066298:In Vitro Techniques; D009363:Neoplasm Proteins / Q000494:pharmacology; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments / Q000494:pharmacology; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014590:Uterine Contraction / Q000187:drug effects* / Q000502:physiology
D009363:Neoplasm Proteins; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments; D011506:Proteins; C054296:parathyroid hormone-related protein (1-34); D000109:Acetylcholine