A sample of gastric juice is aspirated. the antrum. The loss of parietal cells leads to achlorhydria (absent HCl production), and to deficiency of intrinsic factor. secretion of gastric juice means increased secretion of parietal cell juice.
In achlorhydria and hypochlorhydria, there is low or no gastric acid in the stomach, potentially leading to problems as the disinfectant properties of the gastric lumen are decreased. Gastric acid is produced by cells in the lining of the stomach, which are coupled in feedback systems to increase acid production when needed. The enteroendocrine cells also secrete glucose -dependent insulinotropic peptide.
In our study, both esomeprazole 20 mg q.d. and 20 mg b.i.d. achieved median gastric acid inhibition rate of 100% at steady state. The effect of increasing the dose and frequency of esomeprazole on gastric acid inhibition in this study corresponds with the results of previous western studies using 24-h pH monitoring. Gastric acid inhibition rates in each subject at steady and trough states are indicated.
To ascertain the links between feeding habit, whole-animal metabolism, and GI metabolism and function, we measured postprandial and preprandial metabolic rates and gastric and intestinal acid-base secretion, epithelial conductance and oxygen consumption for the frequently feeding diamondback water snake (Nerodia rhombifer) and the infrequently feeding Burmese python (Python molurus). Independent of body mass, Burmese pythons possess a significantly lower standard metabolic rate and respond to feeding with a much larger metabolic response compared with water snakes. While fasting, pythons cease gastric acid and intestinal base secretion, both of which are stimulated with feeding.
This is true whether the acid secretion is stimulated physiologically by eating (mediated by gastrin and cholinergic pathways), or the sight, taste or smell of food (vagal pathways, gastrin); or by infusion of histamine experimentally, acetylcholine or gastrin. Fig. 1Two cell types in the mucosa of the corpus of stomach are principally responsible for secretion of acid.
It measures the level of acidity in stomach contents also. Chloride and sodium ions are secreted actively from the cytoplasm of the parietal cell into the lumen of the canaliculus. This creates a negative potential of -40 mV to -70 mV across the parietal cell membrane that causes potassium ions and a small number of sodium ions to diffuse from the cytoplasm into the parietal cell canaliculi. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring that it does not become acidic too.
The chemical action of free amino acids and peptides excites the liberation of gastrin from the antrum into the circulation. Thus, there are mechanical, chemical, and hormonal factors contributing to the gastric secretory response to eating. This phase continues until the food has left the stomach.
The pH of the gastric contents determines whether some substances are absorbed. At a low pH, for example, the environment is acidic and aspirin is absorbed from the stomach almost as rapidly as water, but, as the pH of the stomach rises and the environment becomes more basic, aspirin slowly is absorbed more.