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Cytosolic chloride ions stimulate Ca 2+ ‐induced exocytosis in melanotrophs
Author(s) -
M Rupnik,
R Zorec
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80524-k
Subject(s) - exocytosis , cytosol , chloride , intracellular , chemistry , secretion , biophysics , chloride channel , anterior pituitary , membrane , endocrinology , medicine , biochemistry , biology , hormone , enzyme , organic chemistry
We used the whole‐cell patch‐clamp technique to study the secretory activity of single cells by monitoring changes in membrane capacitance [Neher, E. and Marty, A. (1982) Proc. Natl. Acad. Sci. USA 79, 523–535] in anterior pituitary cells. Unexpectedly we have observed that increasing intracellular chloride ions stimulate Ca 2+ ‐induced exocytosis in a dose‐dopendent fashion ( K d = 12 mM). These results demonstrate a role of cytosolic chloride ions in the regulation of exocytotic secretion in anterior pituitary cells. It is suggested that chloride channels, in addition to playing a part in regulating membrane electrical activity [Korn, S.J., Bolden, A. and Horn, A. (1991) J. Physiol. 439, 423–437; Penner, R., Matthews, G. and Horn, A. (1988) Nature 334, 499–504] and cytosolic pH [Kaila, K. and Voipio, J. (1987) Nature 330, 163–165], are also involved in the modulation of cytosolic chloride concentration and thus in the control of exocytosis.