Effects of Pyridoxine on Selected Appetite Regulating Peptides mRNA Expression in Hypothalamic PVN/ARC Nuclei and Gastrointestinal Tract Tissues

An experiment was conducted to investigate the effect of dietary pyridoxine on the gene expression of appetite-regulating peptides in the hypothalamus and gastrointestinal tract of rabbits. Thirty-two rabbits were randomly divided into 2 treatments for 8 weeks (16 replicates/group and 1 rabbit/replicate). The treatments were fed a basal diet (control, measured pyridoxine content is 4.51 mg/kg) and the basal diet with a pyridoxine supplementation at 10 mg/kg (pyridoxine, measured pyridoxine content is 14.64 mg/kg). The results showed that dietary pyridoxine did not significantly alter the mRNA levels of neuropeptide Y, agouti related peptide, pro-opiomelanocortin and cocaine, amphetamine regulated transcript, peptide YY and cholecystokinin in arcuate nucleus, peptide YY in jejunum and ileum, and cholecystokinin in duodenum, jejunum and ileum (P > 0.05). Compared with the control, the mRNA levels of corticotropin-releasing hormone and melanocortin 4 receptor in paraventricular nuclei and peptide YY in duodenum were significantly decreased after pyridoxine treatment (P < 0.05). In conclusion, the appetite genes of melanocortin 4 receptor and corticotropin-releasing hormone in paraventricular nuclei and peptide YY in duodenum are involved in the pyridoxine-caused hyperphagia.