title: Direct effect of parathyroid hormone on rat uterine contraction.
abstract: Synthetic bovine parathyroid hormone containing the 1-34 NH2 terminal amino acids [bPTH-(1-34)] is capable of inhibiting stimulated uterine contraction. The purpose of the present investigation is to determine whether the inhibitory action of bPTH-(1-34) is a direct action of the hormone fragment. The effect of different synthetic preparations of bPTH-(1-34), salmon calcitonin, corticotropin-inhibiting peptide and bovine serum albumin on oxytocin-stimulated uterine contraction was determined. In addition, the effects of atropine, propranolol, phentolamine, pyrilamine, cimetidine and the prostaglandin synthetase inhibitor indomethacin on the inhibitory action of bPTH-(1-34) on uterine contraction was determined. Both synthetic preparations of bPTH-(1-34) inhibited oxytocin-initiated contractions similarly. Salmon calcitonin, corticotropin-inhibiting peptide, and bovine serum albumin did not alter oxytocin-stimulated uterine contractions. The salmon calcitonin also did not alter the ability of bPTH-(1-34) to exert its inhibitory effect on uterine contraction. Cholinergic, alpha and beta adrenergic, histaminergic (H1 and H2) and prostaglandin synthetase inhibitors did not alter the action of bPTH-(1-34). These results suggest that the action of bPTH-(1-34) is 1) not due to the presence of a contaminant in the synthetic hormone preparation and 2) that the effect could be due to a direct action effect of the hormone fragment on uterine tissue.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002116:Calcitonin / Q000494:pharmacology; D005260:Female; D009638:Norepinephrine / Q000494:pharmacology; D010121:Oxytocin / Q000494:pharmacology; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D019379:Teriparatide; D014590:Uterine Contraction / Q000187:drug effects*
chemical_list: D010281:Parathyroid Hormone; D010446:Peptide Fragments; D019379:Teriparatide; D012710:Serum Albumin, Bovine; D010121:Oxytocin; C026034:ACTH (7-38); D001285:Atropine; D000324:Adrenocorticotropic Hormone; D002116:Calcitonin; D011433:Propranolol; D011738:Pyrilamine; D009638:Norepinephrine; D010646:Phentolamine