A Cytochemical Study of the Responses of the Adrenal Cortex of the Rat to Thiamine, Riboflavin, and Pyridoxine Deficiencies

Abstract
Severe dietary deficiencies of thiamine, riboflavin and pyridoxine were produced in weanling male rats. Weight changes of the adrenals and thymus glands, and cytochemical studies of the ketosteroids in the adrenal cortices show that the lack of thiamine causes stimulation of the zona fasciculata of the adrenal cortex in 2 weeks and its exhaustion in about 4 weeks in a fashion comparable to that induced by pantothenic acid deficiency (Deane and McKibbin, '46). These changes are attributed to a stimulation of the adrenal cortex by adrenotropin, resulting in an increased production and secretion of the corticosterone-like hormones. The latter hormones in turn produce thymus involution. In a paired feeding experiment it was found that stimulation of the fasciculata occurs earlier in thiamine deficiency than with a comparable degree of inanition. On the other hand, neither a riboflavin nor a pyridoxine deficiency causes more than a transitory stimulation of the adrenal cortex, although a lack of pyridoxine results in acute involution of the thymus.