Gap junctions in human umbilical cord endothelial cells contain
multiple connexins.
Van, Harold V. M., Rijen, Marjan J. A. Van Kempen, Luc J. S. Analbers,
Martin B. Rook, Antoni C. G. Van Ginneken, Daniel Gros, Habo J.
Jongsma.
Department of Medical Physiology and Sports Medicine, Faculty of
Medicine, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht,
The Netherlands, Department of Physiology, Faculty of Medicine,
University of Amsterdam, A.M.C. Meibergdreef 15, 1105 AZ Amsterdam,
The Netherlands, IBDM, Laboratoire de G[acute]en[acute]etique et
Physiologie du D[acute]eveloppement, Universit[acute]e de la
M[acute]editerran[acute]ee, 13288 Marseille C[acute]edex 09,
France
APStracts 3:0251C, 1996.
We investigated the expression pattern of gap junction proteins
(connexins, Cx) in situ, and in vitro, and their functional
characteristics in cultured human umbilical vein endothelial cells
(HUVEC) and cultured human umbilical artery endothelial cells
(HUAEC). Both in arteries and veins Cx37, Cx40, and Cx43 could be
detected in situ and in vitro (passage 2-4). Distribution patterns of
Cx40 and Cx43 were homogeneous in situ, but more heterogeneous in
vitro. Cx37 is heterogeneously expressed, both in situ and in vitro:
between the majority of cells no Cx37 staining could be detected,
when present, it was found as bright spots between some clusters of
cells. Connexin40 (Cx40) was more abundant in cultured arterial
endothelium than in cultured venous endothelium. Dye coupling
experiments with Lucifer Yellow CH (LYCH) revealed extensive dye
spread in HUVEC (15.2+/-0.4, mean+/-S.E.M., n=110), while restricted
significantly in HUAEC (9.8+/-0.3, mean+/-S.E.M., n=110).
Electrophysiological gap junctional characteristics were determined
in cultured HUVEC and HUAEC pairs, using the dual voltage clamp
technique. In contrast to the dye coupling experiments, mean
macroscopic electrical conductance (gj) was significantly larger for
HUAEC pairs (31.4+/-6.0 nS, mean+/-S.E.M., n=12) than for HUVEC pairs
(16.6+/-2.8, mean+/-S.E.M., n=18). In HUVEC, we measured multiple
single gap junction channel conductances ranging from 19 up to 75 pS.
Interestingly, additional conductances from 80 up to 200 pS were
measured in HUAEC which may partially reflect activity of channels
formed of Cx40, that are more abundant in the cultured arterial
endothelial cells.
Received 10 April 1996; accepted in final form 16 July 1996.
APS Manuscript Number C195-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 21 August 1996