Abstract
Summary
After subcutaneous injection of radiophosphorus, secretion was induced by electrical stimulation of the preganglionic sympathetic and parasympathetic innervation to the submaxillary gland of the cat. Saliva was collected from the stimulated submaxillary gland and analyzed for Na+, K+ and hexosamine (mucin). Analysis for phosphorus and radioactivity on the different phosphorus-containing fractions have shown an augmentation in the specific activity of the phospho-inositide complex and phospholipid fractions from the electrically stimulated gland. No increase was apparent in the radioactivity of the total acid-soluble or 7-minute hydrolyz-able fractions. By means of TLC chroma-tography, monophosphoinositide was found to be the fraction responsible for the augmented turnover. The data obtained to date indicate that there are two types of phosphorus atoms in the phosphoinositide complex: one type being a monophosphate ester which is responsible for the relatively high metabolic activity and the other being the phosphodiester between glycerol and inositol which appears to be involved in secretory phenomena. It is believed that the phosphoinositide in conjunction with a membrane protein is actively involved in transport characteristics of the secreting cell.
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