Lymphocyte norepinephrine and epinephrine, but not plasma catecholamines predict lymphocyte cAMP production

Endogenous norepinephrine (NE) and epinephrine (E) were demonstrated in lymphocytes isolated from peripheral venous blood. In 13 young subjects lymphocyte NE and E averaged 14.3 and 1.9 pg per 10(7) cells, respectively. The ratio NE/E was similar in plasma and in lymphocytes. Highly significant correlations were obtained between lymphocyte NE and E on the one hand and cAMP in lymphocytes on the other both in the basal state and after stimulation with isoproterenol. In a group of elderly subjects lymphocyte NE concentration was significantly reduced in long-term smokers as compared to non-smokers (7 and 35 pg/10(7) cells, respectively), whereas plasma NE was increased in smokers. Addition of exogenous NE or propranolol to blood samples did not change lymphocyte NE concentration in in vitro experiments. Variability in endogenous lymphocyte concentration of E in 9 young subjects, correlated with concomitant changes in number of NK(CD3-CD56+) cells and cAMP. It is concluded that endogenous lymphocyte NE and E concentrations in healthy subjects reflected basal cAMP production in lymphocytes and lymphocyte subset composition.