Proteinase-activated receptor-2 activation induces uterine contractility in term pregnant rats that is not dependent on mast cell activation and cyclo-oxygenase products.
OBJECTIVE
This study was undertaken to evaluate the effect of proteinase-activated receptor-2 (PAR-2) activation on the contractility of uterine tissues from term pregnant rats and the role of mast cells and prostaglandins in such an effect.


METHODS
Uterine rings from pregnant (day 20-21) Sprague-Dawley rats were used for isometric tension recording in organ chamber experiments (Krebs solution, 5% carbon dioxide in air, 37 degrees C, pH approximately 7.4). Responses to the PAR-2 activating peptide SLIGRL (serine-leucine-isoleucine-glycine-arginine-leucine), and to the inactive reverse peptide LRGILS (leucine-arginine-glycine-isoleucine-leucine-serine) were determined after pretreatments with compound 48/80, cromolyn, S[+]-chlorpheniramine maleate, cimetidine, combinations of histamine (H) receptor antagonists with cromolyn or ibuprofen and compared with vehicle.


RESULTS
SLIGRL significantly augmented contractility of uterine tissues, and this response was not inhibited by compound 48/80, cromolyn, and ibuprofen, as well as by H(1)- and H(2)-receptor antagonists, alone or in combination with cromolyn.


CONCLUSIONS
PAR-2 activation augments uterine contractility in tissues obtained from term pregnant rats, and this effect is independent of mast cell activation or cyclo-oxygenase pathway products.
Maul
Holger
H
Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, 77755-1062, USA.
Bytautiene
Egle
E
Vedernikov
Yuri
Y
Garfield
Robert E
RE
Saade
George R
GR
D000818:Animals; D002744:Chlorpheniramine / Q000494:pharmacology; D002927:Cimetidine / Q000494:pharmacology; D004205:Cromolyn Sodium / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006632:Histamine / Q000494:pharmacology; D007052:Ibuprofen / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects; D009842:Oligopeptides / Q000008:administration & dosage / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin; D014590:Uterine Contraction / Q000187:drug effects*; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D009842:Oligopeptides; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin; C099570:seryl-leucyl-isoleucyl-glycyl-arginyl-leucine; D002744:Chlorpheniramine; D003189:p-Methoxy-N-methylphenethylamine; D002927:Cimetidine; D006632:Histamine; D004205:Cromolyn Sodium; D007052:Ibuprofen