AUGMENTATION OF OBESE (OB) GENE-EXPRESSION AND LEPTIN SECRETION IN OBESE SPONTANEOUSLY HYPERTENSIVE RATS (OBESE SHR OR KOLETSKY RATS)

To explore the pathophysiologic roles of the obese (ob) gene product, leptin, in the development of obesity and hypertension, we examined ob gene expression and leptin secretion in obese spontaneously hypertens ive rats (obese SHR or Koletsky rats) at the stage of established obes ity and hypertension, Expression of the ob gene was augmented in the e pididymal, mesenteric, subcutaneous, and retroperitoneal white adipose tissue (WAT) from 20-week-old male obese SHR compared to their lean l ittermates (lean SHR). Using a radioimmunoassay for rat leptin, we als o measured plasma leptin levels in 20-week-old lean and obese? SHR. Pl asma leptin levels in obese SHR (292.5 +/- 37.1 ng/ml) were more than 100-fold higher than those in lean SMR (2.8 +/- 1.0 ng/ml). The presen t study demonstrates that ob gene expression and leptin secretion are markedly augmented in obese SHR. (C) 1997 Academic Press.