Catecholamine content of human erythrocytes.

We used high-performance liquid chromatography with electrochemical detection to measure the catecholamine content of human erythrocytes. The ratio of free norepinephrine to epinephrine was three to four times lower than that in plasma and four to seven times lower than that in platelets. This suggests differences in uptake, degradation, or conjugation of norepinephrine and epinephrine by erythrocytes, as compared with plasma and platelets. Erythrocyte free norepinephrine was significantly greater (P less than 0.01) in women than in men.