The zona glomerulosa of the adrenal gland in rats with portacaval shunt. An ultrastructural and morphometric study.

The zona glomerulosa of the adrenal glands was studied histologically, ultrastructurally and morphometrically in portacaval shunt (PCS)-bearing rats 4 weeks after surgery. Compared with controls, the zona glomerulosa of rats with PCS showed an increase in thickness and a reduction in the number of lipid droplets in the cells of its inner portion, adjacent to the intermediate zone. Moreover, electron microscopy and morphometry of the cells of the inner portion revealed that qualitative and quantitative changes occur, consisting in a decrease in lipid droplets, an increase in the amounts of smooth endoplasmic reticulum and mitochondria, enlargement of the Golgi apparatus, and the appearance of numerous dense bodies at the vascular cell poles. All the above findings indicate that PCS induces an enhanced activity of the fully differentiated cells of the zona glomerulosa, which may be considered as an adaptive response--mediated by an activation of the renin-angiotensin system--to the lowering of the systemic pressure taking place in this experimental condition.