Changes in blood cortisol and aldosterone levels and ultrastructure of the adrenal cortex during hemorrhagic shock.

Changes of secretory activity and structure of the adrenal cortex were observed in dogs subjected to hemorrhagic shock. Blood cortisol and aldosterone levels were rapidly increased after hemorrhage. The cortisol level reached a maximum value about 5 times that of normal 1 h after hemorrhage, while aldosterone levels attained maximum levels showing a 10-fold increase over normal, considerably later (at the end of the impending stage) than the cortisol. Cortisol secretion was quickly depleted at the end of critical stage and terminal stage of normovolemic shock, while the aldosterone secretion remained relatively high. Morphologically, sticking of leukocytes to the sinusoidal wall and accumulation of SER around lipid droplets in the fasciculata and reticularis cells became conspicuous 1 h after hemorrhage. At the end of the impending stage, infiltration of leukocytes occurred in the zona fasciculata and reticularis. Irregular masses of fibrin strands appeared in the sinusoidal space and at large gaps of the sinusoidal wall. Degenerative changes such as aggregation of SER, dilatation of endoplasmic reticulum and edema were observed in the cells of zona fasciculata and reticularis, especially of inner half of the former. At the end of the critical stage, small necrotic foci and hemorrhage with inflammatory infiltration were scattered in the inner half of the zona fasciculata. Degeneration of the cells of zona fasciculata and reticularis became more severe in this period, while the cells of zona glomerulosa remained unchanged. At the terminal stage of normovolemic shock after reinfusion, degeneration and necrosis were remarkable in the cells of zona fasciculata and reticularis, especially of the inner half of the zona fasciculata. Moreover, destruction of cordal structure, hemorrhage and inflammatory infiltration were distinct in the zona fasciculata and reticularis, while the zona glomerulosa was relatively well preserved.