Short-Term Starvation Decreases POMC mRNA but Does Not Alter GnRH mRNA in the Brain of Adult Male Rats

Abstract

Dietary restriction reduces circulating gonadotropin and testosterone levels in male rats, an effect thought to be mediated through reduced gonadotropin-releasing hormone (GnRH) secretion; however, the cellular mechanisms subserving this response are still unknown. We reasoned that if dietary restriction reduces GnRH secretion, this would be reflected by a decrease in GnRH synthesis and likewise cellular GnRH mRNA levels. We tested this hypothesis by comparing cellular levels of GnRH mRNA between ad libitum fed (n = 4) and starved (n = 4) adult male rats. Five days of starvation resulted in a 21% decrease in body weight and an 85% decline in serum testosterone levels (fed: 13.9 ± 2.00 vs. starved: 2.1 ± 0.70 nmol/l; p