Possible Effects of Riboflavin Deficiency on Adrenal Cortical Function in the Rat

Abstract

In rats showing impaired growth and liver enlargement from riboflavin deficiency there was a decrease in the weights of thymus and spleen and a slight increase in the weight of adrenals, but these were also shown by control rats with the same degree of growth impairment from inanition. There was no effect upon the ascorbic acid content of the adrenals, and a questionable effect upon their cholesterol content. There was some decrease in the number of circulating lymphocytes. There was a decrease in the catalase activity of the liver, but this was complicated by a relationship to the amount of dietary protein. These observations oppose the concept that in riboflavin deficiency adrenal cortical function is impaired, and suggest that it is slightly stimulated.

Effect of riboflavine deficiency on incorporation in vivo of [14C]amino acid into liver proteins of rats

“…The unaltered liver protein synthesis in riboflavine deficiency is further confirmed by the unimpaired incorporation of [Wlamino acid into liver protein as noted in the present investigation ( Table 2). That liver protein synthesis is unimpaired in riboflavine deficiency, as found in the present experiment, agrees with the results of Mookerjea & Hawkins (1960) and Mookerjea & Jamdar (1962), who noted that the capacity of the riboflavine-deficient liver to regenerate proteins was not affected by partial hepatectomy or protein depletion. It is noteworthy that the mitochondrial fraction of riboflavine-deficient liver showed enhanced incorporation of [14C]amino acid into protein, while the microsomal protein showed reduced uptake of [14C]amino acid ( Table 2).…”

“…Investigation on the subcellular fractions of rat liver showed that transaminase enzymes are mostly located in the mitochondrial fraction (Eichel & Bukovsky, 1961). I n riboflavine deficiency both aspartate aminotransferase and alanine aminotransferase activities are enhanced in liver (Mookerjea & Jamdar, 1962;Chatterjee et al 1966). These increased transaminase activities may be related to the enhanced mitochondrial protein synthesis resulting in increased synthesis of apoprotein of transaminases in riboflavine deficiency.…”

“…Control rats were pair-fed with riboflavine-deficient rats. The diet contained 16 yo protein (vitamin-free casein) along with other ingredients, which were the same as those described by Jamdar & Mookerjea (1962) and Chatterjee, Roy & Ghosh (1969). Water-soluble vitamins were supplied daily by subcutaneous injections.…”