Gastric acid secretion cellular

Mirossay, L., DiGloria, Y., Chastre, E Emami, S. (1992). Pharmacological control of gastric acid secretion molecular and cellular aspects. Bioscience Rep. 12, 319-368. 

Histamine is a chemical messenger that mediates a wide range of cellular responses, including allergic and inflammatory reactions, gastric acid secretion, and possibly neurotransmission in parts of the brain. Histamine has no clinical applications, but agents that interfere with the action of histamine (antihistamines) have important therapeutic applications. 

The antiviral activities of SDB and SDC were suggested to be in part attributed to inhibition of viral DMA polymerase activity and direct inactivation of virus, respectively. The synergistic anti-HSV-1 effects between SDC and ACV/GCV were supposed to be manifested by increasing in cellular ACV-TP/GCV-TP level in infected cells. The suppression of gastric acid secretion and bone resorption was revealed to be due to the inhibition of gastric proton pump, and osteoclast formation and pit formation, respectively. 

Dibona DR, Ito S, Berglindh T, et al. Cellular site of gastric acid secretion. Proc Natl Acad Sci USA 1979 76 6689. 

Hjqiochloremia is common in gastrointestinal disease (Svendsen et al 1979), because of the loss of gastric hydrochloric acid in high volume reflux from the stomach (in proximal enteritis and grass sickness) and the secretion and/or lack of absorption of chloride in severe colitis. It may also occur in exhausted horse syndrome, chronic compensated respiratory acidosis and following furosemide (frusemide) administration. Hypochloremia in the absence of hyponatremia results in a metabolic alkalosis (Corley Marr 1998). The alkalosis associated with hypochloremia may also result in increased cellular uptake of potassium, leading to hypokalemia (Schaer 1999). 

Cyclic AMP has been shown to be involved, presumably as a second messenger, in more than forty cellular processes, in addition to the release of glucose. Among its effects are the increased contractility of heart muscle, increased secretion of hydrochloric acid by the gastric mucosa, decreased aggregation of blood platelets, and increased or decreased formation of several enzymes. Further study of cyclic AMP and perhaps of other second messengers should provide much more information about how the cells of an organism collaborate with one another. 

Activity of the H,K ATPase results In a primary secretion of 160 mM of HCl Into the secretory canaliculus. Because the H,K ATPase Is electroneutral. It Is necessary that the KCl permeability pathway assodated with the canaliculus transfer a minimum of 160 mmol of KCl for each liter of acidic fluid secreted. This Is true whether the KCl pathway consists of conductive or electroneutral transporters. It Is likely. In fact, that the KCl pathway allows transfer of a slight excess of KCl over the minimum required for the production of HCl. This Is suggested both by the observation that gastric secretions contain a low but significant concentration of KCl and by the likelihood that the H,K ATPase Is not fully efficient at recovering K from the canalicular fluid. In the absence of other mechanisms, the combined activity of the transporters at the apical pole of the parietal cell would lead to alkallnizatlon of the cell and depletion of cellular Cl" and K. The potential disturbances In electrolyte balance are prevented by the activity of transporters at the basolateral membrane. These Include an anion exchanger (AE, HCOj /Cl"), a sodlum/proton exchanger (NHE), and the Na,K ATPase. 

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