GAP JUNCTION FORMATION IN HUMAN MYOMETRIUM - A KEY TO PRETERM LABOR

OBJECTIVE: The purpose of this study was to determine if gap junctions are a necessary component of the human laboring uterus and if their p resence in myometrium is a prerequisite for both term and preterm labo r. STUDY DESIGN: We obtained 27 human myometrial samples at cesarean s ection or nongravid hysterectomy. Gap junction formation was analyzed in a blind fashion by freeze fracture and indirect immunofluorescence. Six samples were obtained from term patients with no labor, six from term patients in labor, six from preterm patients with no labor, six f rom patients in preterm labor, and three from nongravid hysterectomy s pecimens. RESULTS: Gap junction structures were identified in the huma n myometrium of patients in term and in preterm labor but not in the o ther patient samples. In addition, evidence was obtained for the expre ssion of (alpha1) gap junction ribonucleic acid and (alpha1) gap junct ion protein in term samples of human myometrium. CONCLUSION: Gap junct ions are a necessary component of the human myometrium during term and preterm labor. The formation of gap junctions may be a final common e vent for the development of labor, and inhibition of gap junction acti vity could be a novel approach for the treatment of preterm labor.