Resting blood flow was measured in isolated, innervated, epigastric fat-pads of 27 male rabbits during growth in the 1st yr of life and found to vary widely in range (7.6-28.1 ml/100 g tissue per min). Definition of adipose tissue composition and of fat-cell size and number made it possible to explain the wide range of flow and to identify two types of relationships between adipose blood flow and tissue constituents. Expressed in the usual manner (ml/100 g tissue per min), adipose blood flow declined with increasing adiposity of the fat depots, and a negative correlation was found between flow and fat-cell volume (r equals -.571, P less than .01). In contrast, when blood flow was expressed on the basis of fat-cell number (ml/108 fat cells/min), a positive and highly significant correlation was found between blood flow per fat cell and fat-cell volume (r equals .842, P less than .001). In the rabbit tissue the relationship of blood flow to fat-cell number and size was more predictable than the usual expression of flow in terms of tissue wet weight. Food deprivation for 18-24 h did not significantly alter these relationships. The results indicate that changes in adipose tissue composition and cellularity, resulting from growth and from accumulation of lipid in enlarging adipocytes, are important determinants of blood flow regulation to adipose tissue.
- Copyright © 1975 by American Physiological Society