The adrenal homologues in the lungfish Protopterus

Publisher Website
Google Scholar
Abstract
No tissue representing the cortex of the adrenal gland has yet been described in the Dipnoi, though it is known in elasmobranchs and in all tetrapod vertebrates. In the mammalian adrenal, lipine-containing inclusions give the cortical cells a char­acteristic appearance at certain stages of their life history. All those viscera of Protopterus which might be suspected of containing cortical tissue were studied in sections by a histo-chemical technique specific for phospholipines. Large intracellular droplets containing phospholipine were demonstrated in a tissue widely distributed around the kidneys, gonads and dorsal aorta throughout the body cavity. The medullary homologue was identified by the chromaffin reaction, and proved to lie, as stated by Giacomini, in the walls of the intercostal branches of the dorsal aorta. The innerva­tion of these medullary cells, from the sympathetic chains, was demonstrated by a silver method. It is suggested that the lipine-containing tissue is that which became the cortex of tetrapods. Its distribution in Protopterus, and its relations with the medullary cells, are such that the elasmobranch and tetrapod adrenals could be derived from it by varying degrees of suppression and migration of the tissues. Amongst Amphibia the adrenal of the Gymnophiona is most similar in arrangement to that of Protopterus . The lipine tissue is so situated as to be readily available for biochemical and endocrinological studies.

This publication has 3 references indexed in Scilit: