Effect of Vitamin B₁₂ on the Formation of Collagen and Nucleic Acids in the Albino Rat Skins and Granulomas

Abstract

With a view to study the changes in collagen and nucleic acids content of skins and granulomas due to vitamin B₁₂ deficiency, two groups of weanling albino rats were fed for six weeks with the vitamin B₁₂ deficient and supplemented diets respectively and another two groups were raised under similar conditions for inducing granulomas by cotton sponge implantation technique. The analyses of skins, granulomas, urine and plasma showed that neutral saltsoluble collagen, insoluble collagen and RNA and DNA contents of skins and granulomas, the urinary excretion of both bound and free hydroxyproline and the free hydroxyproline content of plasma were all significantly decreased in the vitamin B₁₂ deficient animals compared to the supplemented group. These results collectively show that the synthesis of collagen in skins and granulomas was appreciably decreased in the vitamin B₁₂ deficient group. The analyses of skins further showed that the percent reversibility of gel and α₁- and α₂-chains of neutral salt-soluble collagen appreciably increased, β₁₁- and β₁₂-chains and aldehyde content of the neutral salt-soluble collagen significantly decreased in the vitamin B₁₂ deficient animals, which indicated that the intra-molecular crosslinking of collagen was also impaired.