Biomedical subjects

D V Rayner

Publications and source records attributed to D V Rayner.

38 records · Page 3Linked to original sources

PubMed1987

The influence of gastrointestinal infusion of fats on regulation of food intake in pigs.

1. The influence of gastrointestinal infusions of fat on short-term and 24 h control of food intake were studied in twenty-four pigs fed twice per day and seventeen fed three times per day. The pigs were fitted with up to four catheters placed in the stomach, the duodenum, and at 2, 4 and 8 m from the ligament of Treitz. 2. Various infusions were given into the catheters beginning 30 min before the first meal (two feeds) or second meal (three feeds) of the day and continuing until the end of the feeding period or until the pigs stopped eating. 3. Infusions of a fat emulsion (Intralipid) into the stomach, of oleic acid or glycerol into the duodenum, or of glycerol into the ileum (8 m from the ligament of Treitz) inhibited food intake during the infusion according to the amount of energy infused. 4. Food intake was inhibited by more than the amount of energy infused with duodenal infusion of Intralipid or monoglyceride, or with infusion of Intralipid mixed with bile salts and lipase (but not with Intralipid alone) into 2 or 4 m from the ligament of Treitz. 5. Duodenal infusion of glycerol, and ileal (8 m from the ligament of Treitz) infusion of monoglyceride or glycerol inhibited food intake at the following meal according to the amount of energy infused. 6. It is concluded that fats can exert both pre- and post-absorptive control of food intake and that since Intralipid infusion to the stomach but not to the duodenum inhibits food intake according to the amount of energy infused, it is likely that control of food intake is related to control of stomach emptying. 7. The inhibition of food intake by more than the amount of energy infused during upper intestinal infusion of fat is likely to be a result of digestion of the fat to monoglycerides, and interaction of monoglycerides with receptors in the proximal 4 m of intestine.

Animals↗

PubMed1984

Initiation of migrating myoelectric complex in sheep by duodenal acidification and hyperosmolarity: role of vagus nerves.

Gastrointestinal motility was studied in conscious sheep by X-radiography and by electromyography from chronically implanted electrodes before and after total thoracic vagotomy. Duodenal infusion of 0.5-3 mmol HCl (0.035-0.1 M-HCl) induced premature duodenal regular spiking activity (r.s.a.) within 1-7 min in fifteen of seventeen sheep studied when infused at 20 min after a natural r.s.a. There was no correlation between abomasal pH and any phase of the migrating myoelectric complex (m.m.c.). Duodenal alkalinization by infusion of 0.3 M-Tris buffer (pH 10.2) or 0.1 M-NaHCO3 had no influence on the occurrence of the m.m.c. Duodenal infusion of 20-50 ml 0.5 M-NaCl induced a premature duodenal r.s.a. within 1-5 min in seven of eight sheep. Vagotomy did not prevent the initiation or migration of the m.m.c., but reduced the rate of propagation of the r.s.a. from 40.5 +/- 7.2 (mean +/- S.E. of mean) to 16.7 +/- 0.1 cm/min in the duodenum, from 27.3 +/- 4.1 to 16.6 +/- 0.8 cm/min in the jejunum, and from 21.4 +/- 1.1 to 13.7 +/- 0.7 cm/min in the proximal ileum. Initially the frequency of r.s.a. increased, especially in the duodenum where they recurred at an interval of 98.4 +/- 6.8 min before vagotomy; and at 23.4 +/- 1.8 min in the first 24 h after vagotomy; the interval had lengthened to 86.7 +/- 5.2 min 2-3 weeks after vagotomy. Premature duodenal r.s.a. was not induced by duodenal infusion of HCl in five, or by duodenal infusion of hyperosmolar NaCl in three chronically vagotomized sheep. It is concluded that the vagus nerves contribute to the regulation of the frequency and propagation of the m.m.c. in sheep; duodenal acidification is not essential nor is it the normal stimulus for initiation of r.s.a., but duodenal infusion of HCl or hyperosmolar NaCl can initiate a premature duodenal r.s.a. via the vagus nerves.

Abomasum↗