Measurement of adipose tissue blood flow and perfusion in man by uptake of 85Kr.

Abstract

Blood flow to adipose tissue was determined from the rate of uptake of an inert gas using a perfusion-limited body compartment model. Uptake of Kr[degree]5 from a closed breathing circuit was observed in detail for 6-9 hr. in 27 normal human subjects. Total adipose tissue blood flow ranged from 0.20 to 0.60 liter/min. (mean, 0.401); perfusion rates were 128-3.20 ml/100 g adipose tissue/min. (mean, 2.12 ml). Increased body fat content is associated with an increase in total adipose blood flow. However, the increment in blood flow is smaller than that of adipose tissue so that perfusion per unit adipose tissue decreases significantly with obesity. The results are in general agreement with those obtained from local (subcutaneous) clearance of Xe*33 and from a limited number of experiments on rates of uptake of thio-pental and elimination of N. The perfusion-limited hypothesis may not fully describe the uptake of gases with very high relative lipid solubility (e.g., cyclopropane), and may require modification so as to include supplementary filling of adipose tissues by intertissue diffusion.