The adrenal gland of Triturus carnifex after glucagon administration.

The present work was undertaken in order to investigate the influence of endocrine pancreas on the adrenal gland of Triturus carnifex. Our experiments aimed at studying the effects of intraperitoneal injections of glucagon on ultrastructural morphological and morphometrical features of steroidogenic and chromaffin tissues, as well as serum levels of aldosterone, corticosterone, norepinephrine (NE) and epinephrine (E). With regard to steroidogenic tissue, in January and November, glucagon decreased lipid droplet content in steroidogenic cells, that showed clear signs of increased activity. Moreover, increased corticosteroid serum levels were found. With regard to chromaffin tissue, in January glucagon played a stimulatory role on PNMT enzyme, eliciting an increase in the presence of E granules, and a decrease in the presence of NE granules, in the chromaffin cells. Moreover, increased E serum levels and decreased NE serum levels were found. In November, glucagon gave rise to a decrease in the presence of NE and E granules in the cells; E serum levels were strongly increased, whereas NE serum levels did not undergo any significant change. These findings suggest an involvement of the endocrine pancreas of the newt in the modulation of adrenal gland activity.