A sensitive and specific double-isotope dilution method for assaying norepinephrine and epinephrine separately is described. The method is based on enzymatic conversion of these two catecholamines to their respective metanephrines and was applied successfully to measurement of resting plasma concentrations of norepinephrine and epinephrine in normal subjects with the finding that norepinephrine (0.20 ± 0.08 fig/liter)

The effects of heparin on the electrophoretic pattern of serum have recently been studied in this Laboratory. It had been found that in normal, strictly fasting individuals an intravenous injection of heparin caused no changes in the patterns obtained either by moving boundary electrophoresis or by paper electrophoresis (1-4). On the other hand, in alimentary hyperlipemia and idiopathic hyperlipemia electrophoretic changes were observed. In the patterns obtained by moving boundary electrophoresis the changes consisted of a decrease in the beta-1 globulins to a subnormal value and the appearance of a new component ahead of albumin (1, 2). On the basis of this observation it had been assumed that the pre-albumin component consisted of beta lipoproteins. However, subsequent studies by paper electrophoresis revealed that after an injection of heparin not only the beta lipoproteins but also the alpha lipoproteins showed an acceleration of their electrophoretic migration: The beta lipoprotein lipid band moved with the speed of either alpha-2 globulin, alpha-1 globulin, or intermediary between alpha-1 globulin and albumin and the alpha lipoprotein lipid band moved faster than albumin (3, 4).Because the findings by paper electrophoresis indicated that the pre-albumin component consisted of the alpha lipoproteins and not of the betalipoproteins, as we had originally assumed, it was thought worth while to study in greater detail the effects of heparin on the alpha and beta lipo-

No abstract