ISSN:
1040-452X
Keywords:
Myometrium
;
Parturition
;
Protein trafficking
;
Rat
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Modulation of connexin 43 (cx43) in the myometrium of timed pregnant rats was studied using enzyme-linked immunosorbent assay (ELISA), immunocytochemical localization, and immunoblot. These techniques utilized site-specific antibodies directed against a portion of the carboxyl tail of cx43. We found that cx43 is synthesized several days prior to labor but accumulates within the cytoplasm until parturition, when it is rapidly transported to the plasma membrane and assembled into gap junction plaques at the cell surface. These cx43-positive gap junctions begin to disappear from the plasma membrane within hours of delivery of the last pup and are completely absent within 24 hr following delivery. These structures are apparently internalized and degraded within the cytoplasm. ELISA documents a reduction of total cellular cx43 to baseline levels within 5 days following parturition. While the timing of synthesis, cytoplasmic storage, concentration in apparent Golgi vesicles, and transport to and assembly in the plasma membrane are accelerated in three models of preterm labor, the sequence of these events and the correlation of parturition with the formation of gap junctions are identical to those documented in normal labor. These results support the hypothesis that effective labor requires the synthesis and assembly of cx43 into functional gap junctions at the myometrial cell surface. © 1992 Wiley-Liss, Inc.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1080330105
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