Nucleotide metabolism in spleen and peripheral blood lymphocytes during theophylline treatment

The in vivo effect of theophylline on lymphocyte nucleotide metabolism was investigated. Rat peripheral blood lymphocytes presented more elevated levels of adenosine 5'-triphosphate (ATP) and cyclic adenosine 3',5'-monophosphate (cAMP) than shown by spleen lymphocytes. A continuous (15 days) daily oral treatment of the rats with aminophylline increased intralymphocytic cAMp content in peripheral blood (by 14 times) and in spleen lymphocytes (by 4 times), whereas ATP content was not significantly changed. NAD+ and NADH levels and NAD+/NADH ratios appeared higher in peripheral blood than in spleen cells, and were not influenced by aminophylline treatment. These results may be explained by assuming the existence of a different distribution of lymphocyte subpopulations and of a different sensitivity of the same to aminophylline treatment. The studies of nucleotide variation in peripheral blood lymphocytes incubated at 37 degrees C in anoxic conditions (N2+CO2, 95:5) revealed an impairment of ATP production and a well-preserved redox state.