Alteration of membrane phospholipids in hypertrophied rat salivary glands induced by chronic administration of isoproterenol.

Hypertrophy of parotid and submandibular glands, and elevated phospholipid content per gland in both were induced. However, phospholipid content per tissue weight increased only in the parotid gland. Sublingual gland phospholipids were unaffected with regard to the gland weight and phospholipid content; phospholipid class compositions were altered in each of the three glands, typically an increase of phosphatidylcholine and decreases of sphingomyelin and phosphatidic acid. Concerning fatty-acyl groups in phospholipid, prominent increase of octadecadienoic acid was observed in total and individual phospholipids of both parotid and submandibular glands. However, eicosatetraenoic acid decreased in the total phospholipids of these two glands. In the sublingual gland, phospholipids, fatty-acyl compositions were not changed by isoproterenol. The results suggest that isoproterenol-induced changes of membrane phospholipids are regulated by at least two different effects, one for fatty-acyl groups and another for base moieties of phospholipids.