Secretion by salivary glands deficient in acini

¹ Departments of Physiology and Dentistry, University of Alabama Medical Center, Birmingham, Alabama

Rat submaxillary and parotid glands deficient in acini were obtained by selecting normal early postnatal animals or by ligating gland excretory ducts in adult animals. Acinar deficiency under these conditions was histologically confirmed for submaxillary and demonstrated for parotid glands. Glands with pronounced acinar deficiency secreted in response to pilocarpine. Flow rate, in the early postnatal state, approximated that from normal adult glands, whereas from ligated glands, flow was frequently reduced. In the two experimental conditions, potassium levels of the secretions from both glands were uniformly high (about 50 mEq/liter), approximating normal adult submaxillary levels. Sodium concentration was altered from normal only in parotid secretion of early postnatal animals where it was reduced, and in submaxillary secretion of ligated gland where it was elevated. These results, while not establishing the extent of secretory activity in the normal adult condition, demonstrate the capacity of ductal elements to secrete water, sodium, and potassium at rates frequently approaching those of normal adult glands.