The effects of an inhibitor of Na plus -K plus -active transport on the secretory activity of rat submaxillary gland cell cultures.

Abstract

The role of electrolyte transport in the metabolism of mucosubstance has been investigated using cell cultures derived from rat submaxillary gland. When added to the culture medium at a concentration of 1 mM, ouabain, an inhibitor of active alkali metal ion transport through cell membranes, causes extensive cytoplasmic vesiculation suggestive of an accumulation of secretory materials within the cell; the rough ER and cytoplasmic polysomes are not affected. Isotopic experiments support these conclusions by demonstrating that ouabain inhibits the secretion of radioactive mucosubstances by the cells; comparative studies with ouabain and puromycin (2×10−4M) indicate that the inhibitory effect of ouabain is not due to an inhibition of protein biosynthesis. A relationship between secretion and alkali metal ion movement is suggested which may be of significance in connection with the genetic disease, cystic fibrosis.