Studies of a proposed mechanism regulating parietal cell emptying.
We have proposed and provided experimental evidence for the existence of a mechanism controlling the output of hydrochloric acid from the parietal cells. On stimulation of the cells, histamine not only activates the H+/K-pump but also prevents acid from leaving the cell. The delay may be caused by cAMP activation. When the appropriate conditions have been obtained, the acid leaves the cell and enters the gastric lumen. A delay in onset of acid secretion is convenient from several points of view. For example, salivary amylase, which is responsible for approximately 50% of the carbohydrate digestion, will have time to exert its digesting effect in the stomach before the pH decreases and the enzyme becomes inactivated. Also, bicarbonate secretion will be started before high concentrations of acid have been obtained in the stomach and thereby contributes to protection of gastric mucosa.
Nilsson
G
G
Department of Physiology, Swedish University of Agricultural Sciences, Uppsala.
Romell
B
B
Girma
K
K
Seensalu
R
R
D000632:Aminopyrine / Q000378:metabolism; D000818:Animals; D066298:In Vitro Techniques; D010295:Parietal Cells, Gastric / Q000378:metabolism*; D011817:Rabbits; D011969:Receptors, Histamine H1 / Q000502:physiology
D011969:Receptors, Histamine H1; D000632:Aminopyrine