Na+ and Cl− transport and intercellular junctions in the isolated skin of a marine teleost (Blennius pholis L.)

Abstract

AbstractElectrical parameters were simultaneously measured with unidirectional fluxes of Cl− and Na+ through isolated short‐circuited skin of a marine teleost, the shanny (Blennius pholis L.). The mean transepithelial potential TEP developed across the skin was 10.6 ± 0.4 mV (n = 6) in open‐circuit conditions. When the skin was short circuited, the mean short circuit current Isc was 35.1 ± 2.7 μamp·cm−2, which represented the difference between mean Cl− and Na+ net fluxes (1.2 ± 0.2 μEq·hour−1·cm−2 equivalent to 32.5 ± 5.4 μamp·cm−2). The junctional complexes between the different cells of the epidermis were also studied. Epithelial cells were linked to each other by tight junctions as well as epithelial and accessory cells. In contrast, junctions between chloride and accessory cells were characterized as shallow junctions. The Na+ and Cl− transport through the skin of the shanny is discussed with reference to the implication of the junctional complexes of the epidermis.