LYMPHOCYTE SUBPOPULATIONS AND CATECHOLAMINES DAYTIME VARIATIONS AND RELATIONSHIPS

The diurnal variations and their possible relations with endogenous ca techolamines have been studied in 16 apparently healthy subjects (8 wo men and 8 men, between 22 - 35 years of age). A butterfly cannula was inserted into the flexure vein of the elbow at 8 h and at 20 h, a bloo d sample being taken after three 15-minute intervals. Leukocytes, lymp hocytes, monocytes, and granulocytes were quantified in a cell counter while lymphocyte subpopulations were determined with flow cytometry i n cells labelled with specific monoclonal antibodies. Plasma catechola mine concentrations were measured by high-pressure liquid chromatograp hy. Significant differences for leukocyte circulating levels were foun d, as well as for all subpopulations measured at different times of da y, save NK cells and monocytes. A statistically significant correlatio n was also found both between leukocytes, all subpopulations and epine phrine save B lymphocytes and NK cells, and between total lymphocytes, T lymphocytes, CD4, CD4/45RA(+) subtypes and norepinephrine. In concl usion, diurnal rhythms were proved to exist in leukocyte and lymphocyt e subpopulations; the significant correlation between these cells and catecholamine plasma levels suggests the presence of a possible mechan ism thar connects the cellular immunity with determined hormones.