HISTOPHYSIOLOGICAL CHANGES OF THE ADRENAL CORTEX OF THE RAT IN DEHYDRATION AND REHYDRATION

Abstract

SUMMARY The adrenal cortex of rats was studied during different periods of deprivation and re-introduction of drinking water. Dehydration following thirst caused an increase in the width and nuclear volume of the cells of the zona glomerulosa. The cellular hypertrophy of the zone was associated with a rise in the serum sodium level, thus indicating hyperactivity of this zone. After re-introducing drinking water following thirsting, the z. glomerulosa did not show a uniform pattern, regression of its hypertrophy being uneven, and occurring in several animals at different times. Normalization of the zone may be immediately preceded by a temporary increase of activity. Hypertrophy of the z. glomerulosa associated with a rise in serum sodium level may take place simultaneously with both the hypertrophy and the regression of the zona fasciculata and with both hyperfunction and a state of rest (or equilibrium) of the antidiuretic centres. Dehydration following thirsting seems to be a particular type of stress, which exerts a stimulating effect on both external layers of the adrenal cortex alike.