Effects of caffeine on contraction and chlorotetracycline fluorescence in isolated single smooth muscle cells of guinea pig taenia coli.

Abstract

Fluorescent probing with chlorotetracycline (CTC) was employed to test for effects of caffeine on membrane-bound Ca in isolated smooth muscle cells. The decrease in fluorescence by caffeine was associated with the contractile response of muscle cells to caffeine. Caffeine should release the activator Ca2+ from membrane or intracellular stores.