HISTOCHEMICAL-STUDY OF CHROMAFFIN CELLS AND NERVE-FIBERS IN THE ADRENAL-GLAND OF THE FLAT SNAKE (WAGLEROPHIS-MERREMII)

The distributions of tyrosine hydroxylase (TH), protein gene product ( PGP) 9.5, calcitonin gene-related peptide (CGRP), and peptide histidin e isoleucine (PHI) have been examined immunohistochemically in the adr enal gland of the snake Waglerophis merremii. The morphology of chroma ffin cells and the presence of ganglionic neurons in the gland reveale d by means of the glutaraldehyde-silver technique and electron microsc opy are also described. Two distinct types of TH-immunoreactive (-IR) cells are present in the dorsal noradrenergic ribbon: small chromaffin cells and a larger type identified as ganglionic neurons. Small, most ly round or fusiform cells often displayed long processes. Ganglionic cells, arranged in patches, had long processes entering the cortex of the gland. Chromaffin adrenergic cells, forming small groups of 4-7 ce lls, were scattered within the interrenal tissue and had a wide variet y of shapes with processes that appeared to contact other chromaffin c ells. Bundles of PGP 9.5-IR fibers occurred in the subcapsular zone of the adrenal gland with fibers entering the cortex and dorsal noradren ergic ribbon of the gland. Thick and thin TH-IR fibers were seen. Thic k TH-IR fibers were nonvaricose and appeared to originate mainly in ga nglionic neurons. Thin TH-IR fibers with small varicosities were numer ous in the interrenal tissue and were frequently seen between clusters of adrenergic cells in close apposition to cortical cells and vessels . CGRP-IR fibers were present throughout the entire adrenal gland, whe reas PHI-IR fibers had a preferential distribution in the interrenal t issue. Both CGRP- and PHI-IR fibers were closely associated with vesse ls and cortical cells. (C) 1994 Academic Press, Inc.