Comparisons were made between the artery and a heated superficial hand vein (HSHV) for the measurements of amino acids, lactate, glycerol, free fatty acids, insulin and glucagon and the measurements of glucose and alanine kinetics in man. Normal subjects (n = 8) were studied after an overnight fast (12-14 hr). U-14C-alanine and 3, 3H glucose were administered by a constant infusion and blood was sampled from catheters placed in a radial artery and a superficial dorsal vein of a heated hand (68°C environment), during a control period and a period of a steady state hyperaminoacidemia achieved by a constant infusion of an L-amino acid solution. The blood concentrations of all substrates and hormones measured and the concentrations of cold and radioactive glucose and alanine were comparable in the two vessels during both study periods. In contrast, measurements obtained in a deep forearm vein (DV) showed the concentrations of plasma glucose to be lower (3% in the control period and 5% during the experimental period) and those of plasma alanine to be higher (13% and 5% during control and experimental periods respectively) than the artery or the HSHV. The difference in glucose specific activity between the artery or the HSHV and the DV were however slight but non-significant, while plasma alanine specific activity was significantly lower in the DV as compared to the artery or the HSHV (32% in the control period versus 14% in the experimental period) suggesting a process of exchange of alanine and glucose occuring during the transit of blood across the forearm. As a result blood samples obtained from a DV will overestimate the derived total body glucose and alanine turnover rates. Thus the heated superficial hand vein can adequately replace the artery for the measurements of whole blood amino acids, lactate and glycerol and for plasma FFA, insulin and glucagon; its use can obviate the risks associated with arterial catheterization and can be a suitable site for the measurements of total body glucose and alanine kinetics in man.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism