Pineal gland in rats with 7,12-dimethylbenz (a) anthracene-induced mammary tumors subjected to manipulations known as enhancers of pineal actions

Abstract

The ultrastructure of pinealocytes was studied in rats with 7,17-dimethylbenz (a) anthraceneinduced manimary tumors which were subjected to experimental manipulations known as enhancers of pineal actions (anosmia, underfeeding or cold exposure). In these aniinals we found: (1) - more nuclei with deep nuclear invaginations; (11) - a large number of cytoplasmic organelles, including lipid droplets. myeloid bodies, synaptic ribbons and lysosomes; (111) - numerous degenerative changes. In general, we found an increase in structural features related to pineal photoneuroendocrine activity. Our results indicate that pineal-dependent inhibition of neoplastic growth induced by these experimental manipulations, previously reported, can be mediated through an increase in pineal metabolic activity.