Using 5% ethanol as a deciliating agent, 20 mm colchicine to prevent reciliation and 1 mm amiloride to affect ion fluxes in Paramecium we examined the compartmentation and function of Ca2+ fluxes employing the biosynthesis of cGMP and the stereotypic swimming behavior as indicators for Ca2+ entry. As a function of extracellular Ca2+ Paramecia responded to… (More)
In guinea-pig cerebral cortical slices cyclic AMP concentrations increase during incubation with histamine+noradrenaline. After 10 min of incubation the levels of cyclic AMP start to decline. When calcium ions are omitted from the incubation medium, cyclic AMP levels do increase to a greater extent under the same conditions and do not drop during 30 min… (More)
Adenylate cyclase and phosphodiesterase were prepared from brain slices from guinea-pig. The specific activity of adenylate cyclase declined rapidly with increasing incubation time of tissue slices, while phosphodiesterase activity was almost uneffected by the incubation of brain slices.