A study on human adrenal secretion. Measurement of epinephrine, norepinephrine, dopamine and cortisol in peripheral and adrenal venous blood under surgical stress.

Epinephrine (E), norepinephrine (NE), dopamine (DA) and cortisol (F) were measured in samples drawn simultaneously by direct venepuncture from the brachial and the adrenal vein of 12 patients undergoing surgery for left kidney diseases. In 7 patients the influence of anesthesia on peripheral plasma levels was also assessed. Catecholamines were measured by a radioenzymatic assay and F by radioimmunoassay. Compared to basal values (mean +/- SE) (E: 53.6 +/- 6.2 pg/ml; NE: 209.4 +/- 24.4 pg/ml; DA: 24.5 +/- 3.3 pg/ml; F: 12.9 +/- 1.2 micrograms/dl) only NE peripheral levels were significantly modified by anesthesia (NE: 343.7 +/- 67.4 pg/ml p less than 0.05), whereas under surgery a significant increase in the peripheral levels was found for every substance measured (mean +/- SE) (E: 332.5 +/- 46.6 pg/ml p less than 0.001; NE: 633.6 +/- 114.2 pg/ml p less than 0.005; DA: 85.8 +/- 15.7 pg/ml p less than 0.005; F: 21.3 +/- 1.9 micrograms/dl p less than 0.01). Catecholamine and F levels in adrenal vein showed a high variability suggesting an intermittent secretion. In the adrenal venous blood E levels were, in the mean, 381 times higher, NE levels 45 times, DA levels 27 times and F levels 23 times higher than in peripheral blood. E, NE and DA concentrations in the adrenal vein were all significantly correlated to the others but not to cortisol, suggesting that the medulla secrets E, NE and DA in rather constant ratios and that the cortex and the medulla respond differently to surgical stress.