Gastrin-stimulated Gastric Secretion Research Articles

十二指腸潰瘍患者のガストリン投与胃酸分泌におよぼす modified sham-feeding の影響

十二指腸潰瘍患者のガストリン投与胃酸分泌におよぼす modified sham-feeding の影響

Influence of Parasitism on Secretin-Inhibited Gastric Secretion *

This study tested the hypothesis that the inhibitory action of secretin on gastrin-stimulated gastric acid and pepsin secretion is comprised in animals harboring intestinal stages of the parasite Trichinella spiralis. Pentagastrin-stimulated acid and pepsin secretion, and the influence of secretin on these processes, were measured in dogs prepared with gastric fistulas and Heidenhain pouches. Dogs were studied before and after infection with 10(4) T. spiralis larvae/kg body weight. Gastric secretion was stimulated by constant intravenous infusion of pentagastrin, 1 microgram/kg per hour. Exogenous secretin inhibited pentagastrin-stimulated acid and pepsin output from both the main stomach and Heidenhain pouch in infected as well as in the uninfected dogs. Identical inhibition was observed in uninfected dogs during duodenal infusion with HCl to release endogenous secretin. In contrast, duodenal stimulation with HCl did not inhibit acid and pepsin secretion in dogs tested during the 1st week following infection. Results support the conclusion that the regulatory effect of secretin on gastrin-stimulated gastric secretion is impaired during the early phase of infection, and is due to depressed synthesis or release of secretin from duodenal mucosa.

Effect of Secretin on Acid and Pepsin Secretion in Cat and Dog

Secretin in doses which produced a maximal inhibition of gastric secretion in the dog and maximal stimulation of pancreatic secretion in the cat had no effect on gastrin-stimulated gastric secretion in the cat. Irrigation of the duodenum with acid produced a much smaller inhibition of gastrin-stimulated gastric secretion in the cat than in the dog, thus suggesting that endogenous secretin is not so important for the control of acid secretion in the cat as in the dog. We conclude that the disparity between the action of secretin on gastric secretion in the cat and dog represents a true species difference. Identical doses (on a body weight basis) of secretin, however, produced strong stimulation of pepsin secretion in both the cat and dog. Stimulation was produced by continuous intravenous infusions of secretin in doses submaximal for pancreatic secretion. In addition the effect of natural secretin was reproduced exactly by the synthetic hormone, indicating that the stimulation of pepsin secretion is a property of the secretin molecule. Endogenous secretin, released by either exogenous acid in the duodenum or by closing the gastric fistula, reproduced the effect of the exogenous secretin or pepsin secretion. We conclude, therefore, that the stimulation of pepsin secretion is a physiological action of secretin.

Histidine decarboxylase inhibition and gastric secretion.

In a series of rats whose histamine formation was blocked by either pyridoxine deficiency or decarboxylase inhibition with 4-bromo-3-hydroxybenzy-oxyamine dihydrogen phosphate (NSD-1055), we found that basal and gastrin-stimulated gastric secretion was markedly lowered. Histamine stimulation, however, was an effective stimulus in these inhibited rats. Vagal-induced acid secretion through insulin hypoglycemia and direct parasympathomimetic stimulation with bethanechol, the parasympathomimetic drug, were also not blocked in these animals. These results suggest that, at least in the rat: (1) histamine may be an important endogenous chemostimulator of gastric secretion; (2) gastrin stimulates the parietal cell directly through histamine release; and (3) vagal stimulation apparently utilizes, in part at least, a mechanism other than histamine release.

Total protein and total nitrogen in gastrin-stimulated gastric secretion of man.

Total protein (Prot) and total nitrogen (TN) contents of gastric juice were determined in 20-minute portions withdrawn by continuous suction for one hour before and one hour after subcutaneous injection of Gastrin Leo (2 μg/kg body weight) in 19 patients. In 9 of these patients the examination was performed twice. There was an increased concentration ([ ]) and output (Q) of Prot and a decreased [TN] following gastrin administration. The QTN, however, was shown to increase significantly in the post-gastrin hour. It was found that a statistically significant correlation existed between hydrochloric acid concentration ([TA]) and [TN] after gastrin, and between QTA, QProt and QTN before as well as after injection of gastrin. Comparison with values of Prot and TN in gastric juice found by others indicated that gastrin affects the gastric secretion of these substances in the same way as histamine.

Magnesium, Calcium, and Inorganic Phosphorus in Gastrin-Stimulated Gastric Secretion of Man.

Gastrin Leo was injected subcutaneously (2 μg/kg body weight) in 10 patients on 19 occasions, and the gastric juice was aspirated continuously for 1 hour before and 1 hour after the injection. The gastric juice was divided into 20-minute portions and analysed for volume and content of TA, K, Na, Mg, Ca, and P. Concentrations ([ ]) of TA, K, and Mg increased after injection of gastrin, while [Na], [Ca] and [P] decreased. The outputs (Q) of TA, K, and Mg increased significantly, while the QNa and QP showed no significant changes and the QCa decreased after stimulation with gastrin. Statistically, there were highly significant negative correlations between [TA] and [Ca] and between [TA] and [P], Significant positive correlations existed between [Ca] and [P] and between [Ca] and [Mg], There existed a statistically significant correlation between QTA and QMg, and between OTA and QCa, and also between QMg and OK, and QCa. The QCa showed significant relations to all parameters, while the QP was only statistically significantly correlated to QCa. A study of the reproducibility of concentrations and outputs of these ions before and after the injection of gastrin showed that there was a lower grade of reproducibility of Mg, Ca and P than that observed for TA, K, Na, and Cl in the same patients. The values obtained in this study are similar to those found in studies utilizing other secretogogues, mainly histamine. However, the secretion of magnesium was in some respects different from that found earlier, and the conclusion was drawn that this ion stems from other non-parietal sources than do Ca and P.

Comparison of subcutaneous and intravenous administration of pancreatic stimulants.

In conscious dogs with permanent gastric and pancreatic fistulas, the response to single injections of extracts of mucosa of the gastrointestinal tract by intravenous and subcutaneous routes was compared. Both crude and highly purified secretin preparations were weak stimulants of the pancreas by subcutaneous administration, in contrast to the large effect of the same doses given intravenously. An extract containing pancreozymin was effective in causing increased protein secretion by the pancreas by both routes of injection. Gastrin stimulated pancreatic volume flow by subcutaneous administration but not by intravenous administration, in contrast to secretin. This indicates that crude extracts of the mucosa of the pyloric gland area of the hog do not contain enough secretin to be easily detectable. Attempts to show that supramaximal doses of secretin, pancreozymin, and gastrin exhibit self-inhibitory properties when tested on pancreatic secretion were unsuccessful, although self-inhibition of gastrin-stimulated gastric secretion was confirmed.

Gastrin stimulated gastric secretion in man. The effect of repeated doses injected subcutaneously.

Gastrin stimulated gastric secretion in man. The effect of repeated doses injected subcutaneously.

Insulin Inhibition of Gastrin-Stimulated Gastric Secretion

Insulin Inhibition of Gastrin-Stimulated Gastric Secretion

Effect of Acetazolamide on Histamine-Stimulated and Gastrin-Stimulated Gastric Secretion

Effect of Acetazolamide on Histamine-Stimulated and Gastrin-Stimulated Gastric Secretion