Acid Secretion In Stomach Research Articles

Chloride transport, acid secretion and carbonic anhydrase activity in frog stomach

Chloride transport, acid secretion and carbonic anhydrase activity in frog stomach

Acid secretion, potential, and resistance of frog stomach in K+-free solutions

The removal of K+ from the fluids bathing the in vitro frog gastric mucosa results in a decrease of the H+ secretory rate to zero, a marked increase in electrical resistance, a transient increase in potential difference (PD), and relatively little change in the K+ content of the mucosa. The effects of K+ removal are reversed by adding K+ either to the nutrient fluid (4 mm) or to the secretory fluid (104 mm). They are not reversed by voltage clamping (nutrient positive). Following the cessation of H+ secretion, the PD gradually decreases to a level that is low but still greater than zero. The PD under these conditions can be reversibly reduced to about zero by anoxia. It is concluded that the presence of K+ in certain regions of the mucosa is necessary for the functioning of the H+ and Cl– mechanisms.

Studies on the “Mucous Barrier”: Evaluation of Sialic Acid as a Protective Factor Against Degradation of Gastric Mucus by Pancreatic Endopeptidases

Summary 1.In an attempt to define the role of gastroduodenal mucus as a barrier against autodigestion, the protective effect of bound sialic acid against proteolysis of gastric juice nondialyzable substances by the pancreatic endopeptidases was investigated. 2.In the nondialyzable substances of human gastric secretion, there was a small and variable sialic acid content averaging 2.1 per cent weight per weight. 3.Sialic acid bound to mucus can be slowly released under conditions of temperature and pH similar to those in the acid-secreting stomach. 4.Prior release of bound sialic acid had no demonstrable effect on the rate of proteolysis of gastric juice nondialyzable substances by trypsin or chymotrypsin. 5.A protective effect of bound sialic acid against digestion of human gastric mucous substances by pancreatic endopeptidases was not demonstrated.

Acid secretion, potential difference, and resistance of elasmobranch stomach.

The present report is concerned with in vitro studies on gastric mucosa of the skate, Raja eglentaria, the electric ray, Narcine braziliensis, and the shark, Negaprion brevirostris. Maximum secretory rates of from 0.65 to 2.7 µEq hr–1 cm–2 were found. An increase in the secretory rate from an initial low level was associated with an increase in potential difference (PD), a decrease in resistance, and an increase in the calculated short-circuit current. The average PD and resistance before the increase in the secretory rate was 2.2 mv (nutrient positive) and 268 ohms cm2. After the increase they were 6.4 mv and 199 ohms cm2. Thiocyanate (10–2 m) to nutrient resulted in a decrease of secretory rate to zero and an increase in PD and resistance. The results can be explained on the basis of the separate mechanisms theory of H+ and Cl– ion secretion on the assumption that the resistance in the Cl– ion limb of the circuit is considerably lower than that in the H+ ion limb of the circuit.

Rates of insorption of sodium and potassium from stomachs of rats

This study was undertaken to determine rates of insorption of radiosodium and radiopotassium from secreting and nonsecreting stomachs of rats. The methods employed have been described previously. Insorption of radiosodium from gastric contents to blood was always faster in nonsecreting than in acid-secreting stomachs. At the end of 15, 30, and 45 min the mean percentages insorbed from stomachs secreting acid were 1.6, 3.1, and 4.5, whereas from stomach not secreting acid the mean percentages were 5.8, 9.3 and 11.7, respectively. In contrast, the rate of insorption of radiopotassium was unaffected by presence or absence of acid. Its rate of insorption was uniformly low and about equal to the rate of insorption of radiosodium from the secreting stomach. The results demonstrate that the rat's stomach, like that of man and dog, offers a barrier to insorption of sodium which is more pronounced when acid is being secreted and that insorption of potassium, though slow, is unaffected by acid and most likely is independent of insorption of sodium.

Acid secretion, resistance, short-circuit current, and voltage-clamping in frog's stomach.

Certain findings seemed to invalidate the author's separate site theory of HCl formation (separate H+ and Cl– ion electrogenic mechanisms). These findings are analyzed and further pertinent experimental data on the frog's stomach are presented. With an in vitro chamber method it was found that the onset of secretion (histamine stimulation) resulted in a sustained decrease in transmucosal resistance and a small initial increase in potential difference (PD) followed by a larger decrease. The ratio PD/resistance (the predicted short-circuit current, Isc) initially increased and then decreased. During short-circuiting, the onset of secretion resulted in the predicted changes in Isc. Following the establishment of secretion, changes in the H+ ion secretory rate frequently occurred without significant changes in Isc. Thiocyanate inhibition resulted in a transient increase in Isc and a sustained increase in both the PD and resistance. Clamping of the voltage across the mucosa at negative levels (nutrient negative) reversibly decreased the H+ ion rate. The average voltage necessary to reduce the H+ ion rate to zero was –140 mv. With a single loop equivalent circuit the average EMF of the H+ ion mechanism on the basis of the voltage-clamping experiments is 140 mv. Findings are explained by the separate site theory with the assumption of cytoplasmic biochemical coupling.

Hypothalamic influences on hydrochloric acid secretion of the stomach.

Hypothalamic influences on hydrochloric acid secretion of the stomach.

Relation between substrate disappearance and acid secretion in mouse stomach in vitro.

ArticleRelation Between Substrate Disappearance and Acid Secretion in Mouse Stomach in VitroHorace W. Davenport, and Virginia J. ChavreHorace W. DavenportFrom the Department of Physiology, University of Utah College of Medicine, Salt Lake City, Utah, and Virginia J. ChavreFrom the Department of Physiology, University of Utah College of Medicine, Salt Lake City, UtahPublished Online:01 Aug 1951https://doi.org/10.1152/ajplegacy.1951.166.2.456MoreSectionsPDF (804 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByEnergy dependence of restitution in the gastric mucosaAaron M. Cheng, Sarah W. Morrison, David X. Yang, and Susan J. Hagen1 August 2001 | American Journal of Physiology-Cell Physiology, Vol. 281, No. 2 More from this issue > Volume 166Issue 2August 1951Pages 456-461 Copyright & PermissionsCopyright © 1951 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1951.166.2.456PubMed14857203History Received 19 April 1951 Published online 1 August 1951 Published in print 1 August 1951 Metrics

GASTROENTEROLOGY

DUODENUM Congenital Anomalies. —Sumner and Morris217report a case in which duodenal atresia in a newborn infant, diagnosed early, was successfully treated by duodenojejunostomy. In Mosquera's218case the atresia proved fatal at the age of 18 months. Secretion. —Comfort219reviews the literature of the last thirty years on duodenal content in health and disease and reaches the following conclusions: During fasting the duodenal content of healthy subjects with achlorhydria is alkaline; in those with acid-secreting stomachs it is acid both in the fasting state and after meals; the reaction of the duodenal content of healthy subjects varies roughly with the amount of acid entering the duodenum; the acidity does not vary greatly between the first and the second portion; drugs, such as atropine sulfate, morphine and the sodium salt of dehydrocholic acid, increase the averagepHof the duodenal content; the antacids

Effect of Histamine and Alcohol on Acid Secretion of Stomach of Postoperative Cases

ConclusionHistamine and alcohol have their usual action of stimulating gastric secretion in the postoperative surgical patient. Their administration is clinically beneficial.