Removal of exogenous plasma triglycerides in forearm muscle and subcutaneous tissue of hyper-and normotriglyceridaemic men.

Absolute arterio-venous removal and fractional removal of blood-borne exogenous triglyceride particles by skeletal and subcutaneous tissues were determined in eight normotriglyceridaemic and six hypertriglyceridaemic men. Estimations were made by simultaneously sampling blood from catheters inserted into a brachial artery, and in the distal direction, into a superficial and deep vein, draining subcutaneous tissue and skeletal muscle respectively. During the infusion of the fat emulsion IntralipidR for 3 hours steady arterial concentrations of exogenous TG particles were found, indicating first order kinetics. In all subjects absolute arterio-venous and fractional removal of triglycerides were about twice as high in skeletal muscle as in subcutaneous tissue. In skeletal muscle the fractional removal and absolute removal were significantly higher in normotriglyceridaemic than in hypertriglyceridaemic subjects (p less than 0.001). No decrease in removal with time was observed, which would have suggested saturation of removal sites. Mean fractional removal in skeletal muscle was significantly correlated with the k2 value determined by an intravenous fat tolerance test before the infusion study (r = 0.61, p less than 0.05). In subcutaneous tissue fractional removal was also significantly higher in normotriglyceridaemic subjects (p less than 0.05). The results suggest that in both skeletal muscle and subcutaneous tissue the removal system is impaired in hypertriglyceridaemic subjects. This finding supports the concept that a decreased elimination capacity in these tissues may partly account for triglyceride elevation in hypertriglyceridaemic subjects.