The Composition and Mechanism of Formation of Gastric Acid Secretion on JSTOR

(3) Similar questions could apply to frequently feeding snakes and the linear dependence of intestinal maintenance on intestinal metabolism and SMR. Clearly the wide or modest regulation of GI performance for snakes is founded in a complexly integrated selected process. Once the histamine H 2 -receptors on the parietal cell are activated, acid secretion is started via intracellular cyclic AMP. This in turn activates the acid transporter (H + /K + -ATPase) on the luminal side of the parietal cell.

On the other hand, the effect of the dosing regimen of esomeprazole on gastric acid secretion in Japanese people has been insufficiently examined. We, therefore, assessed the relationship between dose and timing of esomeprazole administration and gastric acid inhibition in 11 healthy male Japanese volunteers by directly examining gastric acid secretion capacity. Esomeprazole, a proton pump inhibitor, has been used for treatment of GERD in Japan since 2011; namely, only little is known about its effect on gastric acid secretion in Japanese. Upon the completion of digestion, pythons severely downregulate gastric acid production, pancreatic enzyme secretion, intestinal nutrient uptake, hydrolase activity and base secretion (Secor and Diamond, 1995; Secor and Cox, 2008).

stomach acid secretion rate

Candidates include at least the cellular and molecular mechanisms underlying gastric acid production and intestinal base secretion, cellular growth, microvillus growth, nutrient transport and hydrolase activities. (2) How conserved with respect to phylogeny and/or feeding habits is the adaptive cascade of downregulation of GI function that results in a depression in tissue metabolism which accumulates in a reduce basal metabolism that enhances survival during prolonged fasts? We know that infrequently feeding snakes possess relatively low SMRs and that they downregulate intestinal performance following processing of a meal (Secor, 2005a; Secor and Ott, 2007). This study has shown for one infrequently feeding snake that there is a corresponding decrease in GI metabolism.

Feeding triggers, by direct contact with meal nutrients and/or by neurohumoral stimulation, the rapid upregulation of gastric and intestinal function and hypertrophy of the intestinal mucosa (Secor and Diamond, 1995; Secor et al., 2000; Secor et al., 2001; Secor et al., 2002; Lignot et al., 2005). If the wide regulation of GI performance is an adaptive trait to complement a feeding ecology characterized by predicted long episodes of fasting, then there should predictably be a selective incentive. That incentive is a depression of metabolic rate that allows the animal to survive long episodes of fasting on stored nutrients (e.g. fat bodies and glycogen). We demonstrated for the python that one mechanism underlying a depressed SMR is a significant lowering of organ function and hence metabolism. It is expected, yet to be determined though, that other organs (e.g. liver, pancreas and kidneys) likewise downregulate form and function with fasting, and that their reduced metabolism also contributes to a depressed SMR.

This gives the duodenum time to work on the chyme it has received before being loaded with more.

This tolerance does become a major problem for patients with massive hyper secretion of acid – as in the Zollinger-Ellison syndrome. Tolerance becomes a limiting factor and the control of acid secretion usually fails after some full weeks of treatment. In this rare disease, control of acid secretion with a PPI should be the normal approach. When acid secretion is stimulated with histamine, the systemic adverse effects of histamine can be prevented by a conventional antihistamine drug without affecting acid secretion.

However, acid secretion recovers faster in some patients than others and it may be worth experimenting with switching the dose to the evening. This may benefit patients with reflux whose nocturnal symptoms are not relieved when the PPI is given in the morning.

Snakes exhibit an apparent dichotomy in the regulation of gastrointestinal (GI) performance with feeding and fasting; frequently feeding species modestly regulate intestinal function whereas infrequently feeding species rapidly upregulate and downregulate intestinal function with the start and completion of each meal, respectively. The downregulatory response with fasting for infrequently feeding snakes is hypothesized to be a selective attribute that reduces energy expenditure between meals.

We now believe the main source of this histamine to be the principal endocrine cell of the gastric body or corpus – the enterochromaffin-like (ECL) cell. The ECL cells are located in the lower part of the gastric glands mainly, well-positioned to deliver their histamine into the capillaries which flow past them and the parietal cells (Fig. 1). compared to WT, while pepsinogen secretion was unaffected. Genetic ablation of ClC-2 resulted in reduced gastric gland region, reduced parietal cell number, reduced H/K ATPase, reduced tubulovesicles and reduced stimulated acid secretion. To determine the effect of an intravenous amino acid infusion on gastric acid secretion we measured acid secretion in 7 enterally fed chronically ill infants (age 3-7 mo, weight 2-6 kg) requiring intravenous supplements.

These numbers are converted to actual acid production in units of milliequivalents per hour (mEq/hr) in some cases. The stomach acid test is used to measure the amount of acid in the stomach.

Gastric and intestinal oxygen consumption

Results in normal subjects and in patients with duodenal ulcer. Rune SJ. Comparison of the rates of gastric acid secretion in man after ingestion of food and after maximal stimulation with histamine. Gastrin is in the stomach and stimulates the gastric glands to secrete pepsinogen (an inactive form of the enzyme pepsin) and hydrochloric acid. The secretion of gastrin is stimulated by food arriving in the stomach.

In the absorptive upper intestine, such as the duodenum, both the dissolved carbon dioxide and carbonic acid shall tend to equilibrate with the blood, leading to most of the gas produced on neutralisation being exhaled through the lungs. but the acid is diluted in the stomach lumen to a pH between 1 and 3. in the human stomach lumen, the acidity being maintained by the proton pump H+/K+ ATPase.

[Esophageal and gastric acidity determination: its value and limitations]

Gastric fluid pooled in the stomach was discarded and aspirated under direct observation with endoscopy. Dosing in each regimen was underway Once, acid secretion capacity at steady state and trough state was measured at 2 pm on day 7 of dosing and at 8 am on day 15 (the day after the end of the dosing period), respectively, using EGT. Nagashima and Ikushima (2011) investigated the acid-secretion inhibitory effect of esomeprazole (10 mg, 20 mg and 40 mg q.d.) by monitoring the 24-h intragastric pH in healthy Japanese subjects. We propose that esomeprazole 20 mg b.i.d. is effective for treating Japanese patients with refractory GERD who require long-lasting gastric acid inhibition.

Leave a Reply