Evidence for the secretion of gastrin into human gastric juice.

Abstract

SUMMARY Provided the intragastric pH is greater than 6 and the collected gastric juice is boiled and neutralised immediately, considerable amounts of gastrin-like immunoreactivity can be found in human gastric juice. Characterisation according to size and charge reveals that nearly all the gastrin-like immunoreactivity is similar to gastrin 1-17. Direct stimulation of the G-cells with protein solution is followed by a significant and simultaneous increase of acid secretion, serum gastrin, and gastrin output into the lumen of the stomach in control subjects and patients with duodenal ulcer. consecutive 15 minute periods with 50 ml 10% peptone pH 7.0 (540 mosm/kg, Difco Laboratories, Detroit, Michigan, USA). The perfusate entered the stomach via the tube positioned in the gastric fundus and was collected via the antral catheter in a glass cylinder standing in a boiling water bath. The gastric juice was immediately neutralised by addition of 0.1 N sodium hydroxide. Before neutralisation, the pH of the gastric juice was recorded. Acid secretion per 15 minute sample was determined. Aliquots of venous blood were taken at the end of each collection period. Serum and gastric juice samples were frozen after collection and treatment and stored at -200C.In five healthy volunteers and five patients with duodenal ulcer the stomach was perfused in the same way with 0.42 M sodium bicarbonate adjusted to pH 5.5 with 1 N hydrochloric acid (825 mosm/kg) and 20% peptone pH 5-5 (1080 mosm/kg). The recovered perfusates were treated as described above.To exclude G-cell damage caused by phosphate buffer, the stomach of four control persons and four duodenal ulcer patients was alternately perfused for six consecutive 15 minute periods with 0-6 M sodium bicarbonate adjusted to pH 7.0 with 1 N hydrochloric acid and with 0-15 M sodium phosphate buffer pH 7.0 (flow rate 50 ml/I5 min). The perfusates were boiled, neutralised, frozen, and stored at

Presence and Stability of Gastrin in the Gastric Juice of the Fetal Sheep

“…However, any gastrin in the lumen would be rapidly destroyed by the pepsin in the acid environment (Stadil et a/., 1975). Thus, the demonstration of the release of gastrin into gastric juice and a function from the mucosal side has relied on prior neutralization of the gastric contents (Hengels et al, 1980). In the fetal sheep, however, the gastric juice is generally neutral (Shulkes et a/., 1981).…”

“…Thus the measured endogenous levels in the adult may also consist of C-terminal fragments. The extent of the proteolysis differs in sheep from that in man, since in man, exogenous gastrin is completely metabolized in gastric juice with no C-terminal fragments remaining (Stadil et a/., 1975;Hengels et al, 1980). How gastrin reaches the gastric lumen is unknown.…”

“…Gastrin functions as a circulating hormone, but there have also been proposals that gastrin is secreted into the gastric juice and that this so-called luminal secretion has effects on acid secretion and mucosal growth (Fiddian-Green et al, 1978;Miller & Go, 1980). However, the demonstration of gastrin in the adult gastric lumen has relied on maintenance of the gastric p H at neutrality by perfusion or addition of a neutral buffer (Hengels et al, 1980;Uvnas-Wallensten, 1977). Under normal acidic conditions little gastrin is detected in the gastric juice since it is rapidly destroyed by pepsin (Stadil et al, 1975).…”

Μεταβολες Της Γαστρινης Του Ορου Και Του Πληθυσμου Των G- Και D-Κυτταρων Του Αντρου Και Του Δωδεκαδακτυλου Μετα Απο Χορηγηση Κορτικοστεροειδων Σε Ινδικα Χοιριδια. (Πειραματικη Ραδιοανοσολογικη Και Ανοσοκυτταροχημικη Μελετη)

“…Ή ενδοφλέβια ή ένδονηστιδική χορήγηση αμινοξέων ενώ αυξάνει τήν έκκριση HCl δέν αυξάνει τήν απελευθέρωση γαστρίνης 159 ,169. Θά πρέπει επίσης να αναφερθεί δτι ή χορήγηση ερεθιστικού γεύματος τουλάχιστον στον άνθρωπο αυξάνει καί τις ένδοαυλικές συγκεντρώσεις της γαστρίνης 144 , αν και όπως προαναφέρθηκε άλλοι ερευνητές υποστηρίζουν δτι οι ένδοαυλικές συγκεν τρώσεις τής γαστρίνης δέν αντανακλούν τήν εκκριτική δραστηριότητα των G-κυττάρων 187 .…”