ISSN:
1432-2013
Keywords:
cardiac fibroblasts and myocytes
;
voltage clamp
;
gating
;
gap junction channel conductance
;
connexons
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Recently, the use of the double whole-cell patchclamp technique enable conductance measurements of single gap junctional channels. Different values have been measured in pairs of rat lacrimal cells (6), murine acinar cells and chinese hamster ovary cells (9), embryonic chick heart- (10) and neonatal rat heart myocytes (7). We here present evidence that the conductance of gap junction channels between two different cell types originating from the same tissue, neonatal rat heart, is different. In mixed cultures of cardiac fibroblasts and myocytes, gap junction channels between fibroblasts have a single channel conductance of only 22 pS, while those between myocytes have a conductance of 43 pS. Fibroblasts can be electrically coupled to myocytes through channels having an intermediate conductance of 29 pS, a value which matches very well with te theoretically expected conductance of a gap junction channel composed of a fibroblast- and a myoblast connexon (hemichannel). These data provide direct evidence on the single channel level that in heterologous gap junction channels the composing connexons retain their cell-specific properties.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00585633
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