AJP - Regulatory, Integrative and Comparative Physiology, Vol 247, Issue 2 266-R271, Copyright © 1984 by American Physiological Society
Hemodynamic effects of weight reduction in the obese rat
D. L. Crandall, B. M. Goldstein, R. A. Gabel and P. Cervoni
The effect of defined increments of weight loss on hemodynamics has been
investigated in conscious, unrestrained, spontaneously obese rats. Obese
rats were subjected to a calorically restricted diet and were used for
experimentation on achieving a 10, 20, or 30% reduction in body weight.
After monitoring resting blood pressure and heart rate, radioactive
microspheres were infused for determination of blood flow distribution. Of
10 organs sample, only heart, liver, kidneys, and 2 adipose tissue depots
exhibited significant decreases in weight associated with body weight
reduction. Mean arterial blood pressure remained unchanged, while stroke
volume, left ventricular work, and cardiac output decreased significantly.
Blood flow decreased to kidneys, testes, and adipose tissue through a 30%
reduction in body weight, but the fractional distribution of cardiac output
decreased only to adipose tissue. Therefore the large decreases in renal
and adipose tissue blood flow during weight reduction may contribute to the
associated decrease in cardiac output. Of those vascular beds examined,
however, both absolute and relative blood flow decreased only to adipose
tissue, thus denoting the influence of fat mass on hemodynamics during
obesity.
