[Influence of eosin y and orthovanadate on the steady-state of Ca(+)2 entry into secretory cells of exocrine glands and their spontaneous secretion].
Ca(2+)-pump blocators in low concentrations (eozyn Y up to 5 mM and ortovanadate up to 40 mM) essentially increases of Ca2+ content in salivary gland of Chironomus plumosus larvae's and spontaneous protein secretion. It was shown that eozyn Y much more effectively suppresses of plasma membrane Ca(2+)-pump then ortovanadate. Eozyn Y and ortovanadate in higher concentrations essentially decrease of Ca2+ content in glands and spontaneous protein secretion. The former is evoked by suppression of endoplasm reticulum Ca(2+)-pump, decreasing of Ca2+ influx in cells following by diminishing of Ca2+ transmembrane gradient. Therefore, energydependent Ca2+ transporting systems of plasma membrane and endoplasm reticulum effectively regulate steady-state Ca2+ entry in secretory cells of Chironomus plumosus salivary glands and maintain relatively low level of spontaneous secretion.