Effects of fasting and refeeding on ob gene expression in white adipose tissue of lean and obese (oblob) mice.

A 33-mer antisense oligonucleotide has been utilized as a probe for the rapid chemiluminescence-based detection of ob (obese) mRNA. Expression of the ob gene was evident in several white adipose tissue depots of mice (epididymal, highest; subcutaneous and omental, lowest), but not in other organs. Fasting (24 h) induced a substantial fall in ob mRNA in the epididymal fat of lean mice, which was rapidly reversed on refeeding, responses consistent with the putative role of ob in energy balance. Fasting had no effect, however, on ob mRNA levels in obese (oblob) mice.