Intraluminal Thyrotropin-Releasing Hormone Affects Gastric Somatostatin and Acid Secretion through Its Specific Receptor in Rats

Abstract

Background: Although thyrotropin-releasing hormone (TRH) is present in the gastric mucosa and juice, the pathophysiologic significance of TRH is poorly understood at the peripheral level of the stomach. In the present study we analyzed the TRH-induced secretion profiles of somatostatin, histamine, and acid in the rat stomach. Methods: The effects of intraluminal perfusion of TRH on somatostatin, histamine, and acid and the influence of the specific anti-TRH receptor antibody were investigated by using the rat gastric intraluminal perfusion model. Results: Intraluminal TRH caused an immediate decrease in somatostatin secretion in a dose-dependent manner, and this change occurred preceding an increase in acid secretion. In contrast, this treatment did not yield any significant changes in histamine contents in the effluent. Pretreatment of the gastric lumen with the anti-TRH receptor antibody caused a complete inhibition of TRH-induced changes in somatostatin and acid secretion. Conclusions: These findings suggest that intraluminal TRH affects somatostatin and acid secretion in a paracrine manner via its specific receptor in the rat stomach.