Cl- secretion by cultured shark rectal gland cells. I. Transepithelial transport.
To facilitate analysis of the regulation of epithelial Cl- transport by hormones, neurotransmitters, and autocrine mediators, we have developed a primary monolayer culture system for shark rectal gland (SRG) epithelial cells. Cultures exhibit vigorous transcellular Cl- secretion which can be measured using short-circuit current or 36Cl flux methods. Transport is markedly reduced by bumetanide or barium, inhibitors of Na(+)-K(+)-2Cl- cotransport and K+ channels, respectively. This indicates that Cl- secretion by SRG monolayers occurs by a mechanism similar to that described in numerous native Cl- secretory epithelia. Forskolin, 10 microM 2-chloroadenosine, or vasoactive intestinal peptide, potent secretagogues in the isolated perfused SRG, stimulate Cl- secretion by SRG cultures. Submicromolar concentrations of 2-chloroadenosine, which inhibit Cl- secretion in the native SRG, reduce forskolin-stimulated short-circuit current in SRG cultures. Somatostatin, another inhibitor of Cl- secretion by the native SRG, reduces forskolin-stimulated adenosine 3',5'-cyclic monophosphate accumulation in SRG cultures. These results demonstrate that SRG cultures are fully responsive to mediators which activate or inhibit secretion by the native epithelium.
Valentich
J D
JD
Department of Physiology and Cell Biology, University of Texas Medical School, Houston 77225.
Forrest
J N
JN
D015762:2-Chloroadenosine / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D002034:Bumetanide / Q000494:pharmacology; D002465:Cell Movement; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D004284:Dogfish; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008858:Microscopy, Phase-Contrast; D012491:Salt Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology
D002712:Chlorides; D002034:Bumetanide; D015762:2-Chloroadenosine; D005576:Colforsin; D001464:Barium; D014660:Vasoactive Intestinal Peptide