Degranulation of uterine mast cell modifies contractility of isolated myometrium from pregnant women.
OBJECTIVE
This study was undertaken to test that uterine mast cell degranulation alters human myometrial contractility in vitro and to define what mediators are involved in this process.


METHODS
Longitudinal myometrial strips prepared from biopsy specimen obtained from the lower uterine segment of women at preterm and term gestation (with and without labor) were studied. Contractile responses to compound 48/80, a mast cell degranulator, were compared in the absence or presence of a mast cell stabilizer, H 1 and H 2 receptor antagonists, cyclooxygenase, and lipoxygenase inhibitors.


RESULTS
Compound 48/80 increased myometrial contractility in all groups. The mast cell stabilizer cromolyn inhibited contractility, whereas the cyclooxygenase inhibitor ibuprofen, the H 1 -receptor antagonist S(+)-chlorpheniramine maleate, but not the H 2 antagonist cimetidine, only slightly attenuated this effect. The lipoxygenase inhibitor linoleyl hydroxamic acid augmented the responses to compound 48/80 in the preterm but not in the term group.


CONCLUSIONS
Uterine mast cell degranulation, or the effects of their mediators, can modulate uterine contractility during pregnancy.
Bytautiene
Egle
E
Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Tex, USA.
Vedernikov
Yuri P
YP
Saade
George R
GR
Romero
Roberto
R
Garfield
Robert E
RE
D015550:Cell Degranulation / Q000502:physiology*; D002744:Chlorpheniramine / Q000494:pharmacology; D002927:Cimetidine / Q000494:pharmacology; D004205:Cromolyn Sodium / Q000494:pharmacology; D005260:Female; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D006801:Humans; D007052:Ibuprofen / Q000494:pharmacology; D008041:Linoleic Acids / Q000494:pharmacology; D008137:Longitudinal Studies; D008407:Mast Cells / Q000187:drug effects / Q000502:physiology*; D009215:Myometrium / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D014590:Uterine Contraction / Q000187:drug effects / Q000502:physiology*; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D008041:Linoleic Acids; C089594:linoleic acid hydroxamate; D002744:Chlorpheniramine; D003189:p-Methoxy-N-methylphenethylamine; D002927:Cimetidine; D004205:Cromolyn Sodium; D007052:Ibuprofen