Chloride channel blockers and polyunsaturated fatty acids similarly inhibit the volume activated pathways for cl and taurine in cultured cerebellar neurons. S[acute]anchez-Olea, R., M. Morales, O. Garc[acute]ia, and H. Pasantes-Morales. Instituto de Fisiolog[acute]ia Celular, UNAM, Mexico D.F., Mexico
APStracts 3:0008C, 1996.
The effects of the Cl channel blockers NPPB, DDF, dipyridamole and niflumic acid and of the polyunsaturated fatty acids arachidonic, linolenic and linoleic acids were examined on RVD and associated 125I and [3H]taurine fluxes in cultured rat cerebellar granule neurons were examined. Dose-response curves of NPPB, DDF and dipyridamole showed 20%-100% inhibition of RVD and osmolyte fluxes. Niflumic acid was less potent requiring 150-600 [mu]M to show effects of this magnitude. The polyunsaturated fatty acids (5-20 [mu]M) inhibited 80%-90% RVD and osmolyte fluxes, arachidonic acid exhibiting the most potent effect. The volume associated taurine efflux was somewhat higher in younger neurons but the pharmacological sensitivity was essentially the same in immature and mature cells. The effects of all tested drugs on 125I and [3H]taurine fluxes were remarkably similar, indicating a close pharmacological sensitivity of the transport mechanism for the two osmolytes. This is in line with the suggestion of a common pathway for the volume-associated release of Cl and amino acids functioning as osmolytes. 

Received 12 July 1995; accepted in final form 22 December 1995.
APS Manuscript Number C422-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96