DIFFERENTIAL EXPRESSION OF OB MESSENGER-RNA IN RAT ADIPOSE TISSUES INRESPONSE TO INSULIN

The recently cloned obese (ob) gene encodes a fat-specific mRNA and a protein which is believed to regulate satiety and metabolic rate so as to control far storage. In the present study we investigated rat ob m RNA levels in different fat depots and the effects of insulin infusion on ob mRNA expression. Northern blot analysis showed the abdominal fa t (epididymal and perirenal fat pads) had higher ob mRNA levels than s ubcutaneous fat. After a 2.5-hr infusion of insulin into fasted rats, ob mRNA levels were increased by 3.0 and 1.9-fold in epididymal and pe rirenal fat pads, respectively. However, no change of ob mRNA level wa s observed in the subcutaneous Fat depot. These data demonstrate adipo se depot site-specific expression of ob mRNA and support the hypothesi s that insulin plays an important role in the expression of ob mRNA. ( C) 1996 Academic Press, Inc.