Adipocyte blood flow is decreased in obese Zucker rats

Abstract

Blood flow to five adipose tissue depots and five other organs was measured in unanesthetized free-moving obese and lean male Zucker rats using the radiolabeled microsphere technique. Cardiac output and blood pressure were also measured. Obese rats were significantly heavier and had larger fat depots characterized by more and larger adipocytes. Cardiac output and blood pressure were similar in lean and obese rats. Blood flow to adipose tissue was substantially reduced in all five depots of obese rats when expressed per square millimeter of cell surface. When blood flow was expressed per cell, it was reduced in obese rats in the dorsal subcutaneous and inguinal depots and significantly elevated in the obese mesenteric adipose depot. Significant interdepot differences in blood flow were observed in both lean and obese rats. Nonadipose organ blood flow was not different between obese and lean rats, but when expressed on a per gram basis, blood flow through triceps surae muscle, epididymis, and testis was elevated in obese rats. These findings suggest that there is a substantial alteration of hemodynamics in obesity that may contribute to or reflect the altered metabolism of adipose tissue in obese rats. Furthermore, interdepot differences of adipose tissue blood flow also parallel reported interdepot differences in metabolism.

Autonomic Activity Assessed by Heart Rate Spectral Analysis Varies with Fat Distribution in Obese Women

“…In rats, sympathetic denervation produces greater changes in retroperitoneal compared to epididymal fat depots (4). There are also differences in regional blood flow, which is greater in mesenteric than subcutaneous adipose tissue (32). If similar differences in innervation and blood flow to abdominal fat depots occur in humans, one can speculate that altered sympathetic activity may lead to specific regional accumulations of fat resulting in the subgroup differences we observed.…”

Obesity and Cancer: Evidence, Postulated Mechanisms and Prospectives

“…Nevertheless, there is no increase in cardiac output or blood flow to the adipose tissue, particularly to WAT [96][97][98]. Previous studies on animal models revealed lower levels of oxygen in WAT in obese mice when compared with lean mice [99].…”

The Role of Adipocyte Hypertrophy and Hypoxia in the Development of Obesity-Associated Adipose Tissue Inflammation and Insulin Resistance

“…West et al [32] demonstrated that blood flow to adipose tissue, measured with radiolabeled microsphere, was reduced in Zucker obese rats. In humans, the levels of adipose tissue blood flow were measured with positron emission tomography using [ 15 O]-labeled water [33] and the 133 Xe washout method [34] and were lower in obese compared with non-obese subjects.…”