RT Journal Article
SR Electronic
T1 Dihydropyridine Bay K 8644 activates T lymphocyte calcium-permeable channels.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 239
OP 244
VO 34
IS 3
A1 W Young
A1 J Chen
A1 F Jung
A1 P Gardner
YR 1988
UL http://molpharm.aspetjournals.org/content/34/3/239.abstract
AB The effects of the dihydropyridine calcium channel agonist Bay K 8644 on indo-1-loaded Jurkat human leukemia T lymphocytes was assessed by flow cytometry. Bay K 8644 from 10(-9) to 10(-4) M caused a dose-dependent rise in the intracellular free Ca concentration, an effect that was not mimicked by the dihydropyridine Ca antagonist nifedipine. Single channel recordings by the extracellular patch-clamp technique indicated that Bay K 8644 activated an 8-pS, barium-permeable channel that opened as bursts of brief events. The channel appeared to be identical to the previously described voltage-insensitive, messenger-mediated, calcium-permeable channel involved in T cell activation. The predominant effect of Bay K 8644 on these channels was to increase the probability of channel reopening, apparently without a major effect on mean channel open-time. The results suggest that the dihydropyridine Ca agonist Bay K 8644 interacts with both voltage-gated and receptor-operated Ca channels and also suggest potential strategies for development of a new class of immunomodulatory drugs.