The effect of deficiency of the B vitamin complex (except thiamine) on the blood pressure of the rat.

Certain diets essentially identical with those previously reported as causing an elevation of the blood pressure of rats have failed to produce any elevation. Examination of micro sections from the kidneys of these rats, with the aid of special stains, has failed to demonstrate any vascular lesions similar to those previously described by Calder. Evidence of tubular atrophy was present to a minor degree in sections of the kidneys of rats fed diets deficient in the B vitamins (except thiamine) and in those fed diets low in choline. This finding has been noted previously by others, but examples of this type of lesion were found as well in animals fed the control diets of our experiments. It should be emphasized that these control diets were nutritionally inadequate. Deposits of intracellular granules of hemosiderin were prominent in the convoluted tubules of the kidneys in rats fed the diets deficient in the B vitamin complex.