Cyclic AMP metabolism and nucleic acid content in the lymphocytes of the thymus, spleen, and lymph nodes of protein-deficient rats
Srivastava, U.; Spach, C.; Aschkenasy
Journal of Nutrition 105(7): 924-938
1975
ISSN/ISBN: 0022-3166 PMID: 166150 Document Number: 90791
The concentration of cyclic AMP (cAMP) and its metabolites, 5'-AMP and adenosine, and also adenyl cyclase, cAMP phosphodiesterase and 5'-nucleotidase activities were estimated in lymphocytes of thymus, spleen and lymph nodes of control and protein-deficient male Wistar rats. The values of those variables when expressed per mg DNA and per 108 cells, but not always per mg protein, were much lower in the thymus of the deprived rats than in the spleen and lymph nodes of control rats. The deficient diet increased the nucleotide concentrations in the thymus and spleen lymphocytes expressed on mg DNA basis except those of thymus cAMP, which did not change. The same diet also increased the activities of the enzymes involved in the cAMP metabolism in thymus, spleen and lymph node lymphocytes. Such a peculiarity could be related to the reduction of the mitotic activity of lymphocytes caused by protein deficiency. Purified lymphocyte suspensions contained paradoxically greater amounts per cell of DNA, RNA and protein in the thymus, spleen and lymph nodes of protein-deficient rats than in those of the control rats. When the cell preparations were not purified, only the lymph node cells displayed a large increase in their DNA content. Prolongation of the S phase of the cell cycle in those lymphocytes was suggested.