Lack of histamine involvement in parathyroid hormone hypotensive action.
Promethazine and cimetidine blocked the hypotensive actions of 2-pyridylethylamine, and H1 agonist and dimaprit, an H2 agonist, respectively, but not that of bovine parathyroid hormone fragment [bPTH-(1-34)]. Rats were treated repeatedly with the histamine releaser, compound 48/80, until the release could no longer produce a decrease in blood pressure. The hypotensive action of bPTH-(1-34) could still be seen. Rats with histamine partially depleted with one injection of compound 48/80 were injected with cimetidine and pyrilamine, and H1 antagonist, which together blocked the hypotensive action of subsequent injections of compound 48/80, but not that of bPTH-(1-34). These data suggest that the vasodilatory action of bPTH-(1-34) does not involve the release or action of histamine.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002927:Cimetidine / Q000494:pharmacology; D017259:Dimaprit; D005260:Female; D006632:Histamine / Q000502:physiology*; D007022:Hypotension / Q000139:chemically induced*; D008297:Male; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011398:Promethazine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D013890:Thiourea / Q000494:pharmacology; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D011725:Pyridines; C025076:parathyroid hormone (1-34), bovine; D003189:p-Methoxy-N-methylphenethylamine; D002927:Cimetidine; D006632:Histamine; D011433:Propranolol; C006183:2-(2-aminoethyl)pyridine; D011398:Promethazine; D013890:Thiourea; D017259:Dimaprit