[The sublingual and submandibular glands after preganglionic parasympathetic blockade. A histological, electron optical, autoradiographic and scintigraphic study on the guinea pig].

After preganglionic parasympathetic block three histological and histochemical phases could be determined in the only cholinergically innervated mucous cells of the sublingual gland. The first phase is characterized by overproduction and oversecretion. Possibly this results from acetylcholine overproduction, caused by the block, termed as "degeneration secretion" however of preganglionic origin. Hypersensitivity of the gland parenchyma appears to be present also, which with catecholamins as well as acetylcholine cause the ensuing "paralytic secretion". At the end of the first phase the desquamation of parts of cells, and rarely entire cells, in form of apocrine and holocrine secretion occurs and a uniform cell population is developing. When this cell population develops the second phase starts. The lack of stimulation because of acetylcholine exhaustion is discussed as the cause of the second phase. In the third phase a self regulatory involution commences. In the double innervated serous submandibular gland the effect of chorda tympani section was less severe.