Secretion of Hydrochloric Acid by Ex Vivo Isolated Canine Stomach

Abstract

The ex vivo isolated canine stomach, included in a perfusion system containing a living supporting dog serving as an oxygenator, is able to secrete juice rich in H⁺ for several hours. Blood circulating in this system is homologous blood, and the stomach is stimulated by intra-arterial continuous infusion of histamine. If a bubble oxygenator is used to supply oxygenated autologous or homologous blood to such an ex vivo stomach, only alkaline juice rich in Na⁺ and poor in Cl⁻ is secreted. The hypothesis was considered that in the in vitro system damage, perhaps irreversible, occurs to the H⁺-producing function of parietal cells. To verify this hypothesis, the stomach secreting alkaline juice in the in vitro system was rapidly connected to the system containing the supporting dog, the living animal replacing the disconnected oxygenator. After a certain time ‘recovery’ of parietal cells was observed, and H⁺, in physiological concentrations, appeared in the secretion of the ex vivo stomach. Further studies are conducted to explain this behavior of the ex vivo stomach.

Key-words:

• Histamine
• hydrochloric acid
• stomach