RESUMEN
Objective:This study aimed to explore the Ventromedial Hypothalamic Orexin-1 and Orexin-1 Receptors in Regulation of Gastric Acid Secretion in Conscious Rats.Methods:Rats were anaesthetized and fitted with a stainless steel carmula placed just above the VMH or paracele,after random allocation orexin-A,[Pro34]-peptide YY and [CPP1-7,NPY19-23,Ala31,Aib32,Gln34] -pancreatic polypeptide were injected in the VMH;SB-334867 was intraperitoneal injection;atropine was subcutaneous injection;GR-231118 and CGP-71683 were injected in the paracele.Using pyloric ligation model,tests the effect of different drugs on rat gastric acid secretion and gastric juice volume.Results:OXA induced dose-dependent increase of gastric acid secretion;SB-334867 induced dose-dependent inhibition of gastric acid secretion.The stimulatory effect of OXA on acid secretion was inhibited by SB-334867;atropine induced dose-dependent increase of gastric acid secretion and block the effect of orexin-A on gastric acid secretion;the gastric acid secretion was inhibited by GR-231118 or CGP-71683,and GR-231118 or CGP-71683 were blocked the effect of orexin-A on gastric acid secretion;Intraventromedial hypothalamic injections of [CPP1-7,NPY19-23,Ala31,Aib32,Gln34]-pancreatic polypeptide increased gastric acid secretion.Conclusion:It is suggested that endogenous orexin-A acts on the ventromedial hypothalamus to stimulates acid secretion.This stimulatory effect is probably mediated through orexin receptor,Y1 and Y5 receptor,and the vagus nerve system.