In the present study four groups of rats, each consisting of 30 adult male albino rat were examined. The first group was given food freely and used as control. The second group "three weeks undernourished" was given only 5gm of the same food for 3 weeks, the third group "six weeks undernourished" was given 5gm of the same food for six weeks, and the fourth group "rehabilitated" was given 5gm of the same food for three weeks then allowed to eat freely for 20 days. Water was given freely to all groups. At the end of the experiment the adrenal glands of each group were taken for histlogical and histochemical study. Histologically, the second group showed marked increase in vacuolations in all the cortical cells, increased cell sizes, ballooning and even rupture of some cells. Blood vessels were congested especially in zona fasciculata and zona reticularis in which pigment cells were found. In the third group, there was marked reduction in cellular sizes, depletion of vacuolation in cells. The boundaries of the cells and between zones were indistinct and ill defined as well as loss of the usual cellular arrangement in all zones. There was congestion of blood vessels especially those of zona reticularis in which the number of pigment cells were increased. The fourth group showed the same histological features of all zones seen in control group, but with persistant dilatation of the blood vessels in zona reticularis. Histochemically, the second group showed an increase in lipid, cholesterol and ascorbic acid contents in all cortical zones especially in zona glomerulosa and fasciculata. Alkaline phosphatase activity was increased in the capsule and in all zones. Succinic dehydrogenase activity was increased in all zones and also there was slight increase in acetyl cholinesterase activity along nerves. In the third group there was marked depletion of lipid, cholesterol, and ascorbic acid in all cortical zones and there was reduction in the enzymes activites in all cortical zones and along nerves. In the fourth group lipid, cholesterol and ascorbic acid concentrations in the adrenal cortex was nearly the same as in the control group. Alkaline
phosphatase and succinic dehydrogenase activities were nearly as in the control group except in zona reticularis in which they were higher Acetylcholin-esterase activity was nearly the same as in the control group.