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 presence in myometrium is a prerequisite for both term and preterm labor. STUDY DESIGN: We obtained 27 human myometrial samples at cesarean section 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 from patients in preterm labor, and three from nongravid hysterectomy specimens. RESULTS: Gap junction structures were identified in the human myometrium of patients in term and in preterm labor but not in the other patient samples. In addition, evidence was obtained for the expression of (alpha1) gap junction ribonucleic acid and (alpha1) gap junction protein in term samples of human myometrium. CONCLUSION: Gap junctions are a necessary component of the human myometrium during term and preterm labor. The formation of gap junctions may be a final common event for the development of labor, and inhibition of gap junction activity could be a novel approach for the treatment of preterm labor.