The present application intends to explore some of the functional and structural changes that occur in the salivary glands of mice after a single administration of dl-isoproterenol (IPR). DNA synthesis and cell division are markedly stimulated by dl-IPR, especially in the parotid and submaxillary glands. The investigations outline in this proposal are designed to study the role of secretion and of acidic nuclear proteins in regulating the mechanisms that lead to the onset of DNA synthesis and mitosis in the salivary gland cell of the intact animal.