Calcium fluxes in isolated rabbit aorta and guinea pig tenia coli.

摘要: Studies utilizing 45Ca have been helpful in analyzing the Ca control system smooth muscle. Activation of rabbit aortic alpha receptors stimulates influx and a release from superficial binding sites. Membrane depolarization by high K causes an influx, but no release. However, pathways activated agonists membrane are different independent, because maximal influxes induced each type stimulation additive. The cellular pools that during pharmacological activation shared several agonists; one agent after abolition inhibits second, agonist. U44069, stable prostaglandin H2 analog, induces both extracellular source for initial exchanges more slowly than free interstitial Ca, may be located within glycocalyx or on outer surface. An Na-Ca exchange process has suggested as important determinant transmembrane electrochemical gradient. manipulation Na gradient pump inhibition substitution provided data showing is nonspecific not directly involved regulating [Ca]i. It likely extrusion dependent ATPase