Up-regulation of orexigenic and down-regulation of anorexigenic neuropeptide gene expression in rat hypothalamus after partial lipectomy

Leptin down-regulates orexigenic and up-regulates anorexigenic neuropeptide gene expression in hypothalamus. surgical removal of adipose tissue leads to decrease in circulating leptin concentrations in rats. in the present study,we tested: (a) regulation of neuropeptide gene expression in hypothalamus,(b) food intake,and (c) standard growth rate after removal of adipose tissue in rats. partial lipectomy caused an approximately 10-fold reduction of subcutaneous,retroperitoneal and epididymal adipose tissue weight (at the end of experiments adipose tissue weight was 1.5 ± 0.9 in lipectomy and 15 ± 3.9 g in control rats; statistically significant). compared to control rats,the animals subjected to lipectomy presented increased food intake,standard growth rate,and decreased serum leptin concentrations (2.6 ± 0.8 vs. 3.7 ± 1.2 ng/ml in the controls,statistically significant). these changes were associated with approximately twofold increase in neuropeptide y,threefold increase in agouti-related peptide (orexigenic neuropeptides) and about 50% decrease in pro-opiomelanocortin and cocaine–amphetamine-regulated transcript peptide (anorexigenic neuropeptides) mrna levels in the hypothalamus. these results suggest that partial lipectomy,leading to a decrease in circulating leptin concentrations,may exert an effect on hypothalamic orexigenic and anorexigenic neuropeptide gene expression,and consequently modulate food intake and standard growth rate in rats. © 2015 faculty of health and social studies,university of south bohemia in ceske budejovice