Effect Of Intraduodenal Infusion Research Articles

Effects of intraduodenal infusion of varying combinations of lipid and carbohydrate on antropyloroduodenal motility, hormone release and appetite in healthy males

Effects of intraduodenal infusion of varying combinations of lipid and carbohydrate on antropyloroduodenal motility, hormone release and appetite in healthy males

Effects of Intra-duodenal Infusion of Limiting Amino Acids on Plasma Insulin-like Growth Factor I, Growth Hormone, Insulin and Liver Insulin-like Growth Factor I mRNA in Growing Goat Fed a Maize Stover-based Diet

The effects of intra-duodenal infusion of methionine (Met), lysine (Lys) and leucine (Leu) on dry matter intake (DMI), the concentrations of insulin-like growth factor I (IGF-I), growth hormone (GH) and insulin in plasma, and liver IGF-I mRNA level were investigated in two experiments for Liuyang Black growing wether goats. In Experiment 1, three goats (10.0±0.1 kg) were fitted with ruminal, proximal duodenal and terminal ileal fistulaes to determine the infusion amounts of Met, Lys and Leu at the duodenum according to essential amino acid flows into the duodenum and their apparent digestibility. The infusion amounts were 0.77 g/d, 0.91 g/d and 0.58 g/d respectively. In Experiment 2, 4 groups of goats (10.0±0.2 kg) for each group, were cannulated at the duodenum, and were infused with a mixture of Met, Lys and Leu (Control), or mixtures with 21% Met, Lys or Leu replaced with glutamate respectively on a nitrogenous basis. The replacement of 21% Met, Lys or Leu with glutamate did not affect intakes of maize stover, concentrate or both (p>0.05) when compared with the control. The replacement of 21% Met or Lys significantly (p 0.05). The close relationships between supplying Met and Lys in the lumen of the duodenum and plasma IGF-I, GH and insulin concentrations, as well as liver IGF-I mRNA level in this study indicate that the effects of the limiting amino acids on nutrition of animals are likely intermediated via their effects on these hormones, and these hormone profiles could be used as intermediate markers for the limiting order of amino acids.

Suppression of meal size by intestinal nutrients is eliminated by celiac vagal deafferentation.

The arrival of nutrients in the gastrointestinal tract suppresses intake. To specify the neural pathways and receptor locations of this feedback, we examined the effects of intraduodenal infusions of 10 nutrients plus saline on short-term food intake of rats with selective deafferentations of vagal celiac branches. Three response profiles were observed: 1) isotonic saline, 5.6% glycerol, and 3% fructose did not inhibit intake of controls or selectively deafferented animals; 2) 3% glucose, 3% maltose, 3% L-phenylalanine, 12% Isocal, and 1.4% oleic acid suppressed intake of controls, but this inhibition was eliminated by vagal celiac deafferentation; and 3) 3% casein hydrolysate and 24% Isocal suppressed intake of controls and rats with selective vagotomies, although the latter exhibited significantly less suppression. In addition, elimination of celiac afferents chronically reduced meal size (i.e., first 30-min intake) without reducing daily food intake or body weight. Furthermore, D-phenylalanine infusions produced a delayed suppression of food intake in controls (possibly from intraluminal irritation); however, this reduction was eliminated with celiac deafferentation. Overall, this experiment indicates that vagal celiac afferents are critical for preabsorptive detection of some energy-yielding molecules or properties of nutrient solutions (as well as, perhaps, intraluminal inflammation), but not others, which are still detected, although only partially.

Adaptive cytoprotection of the rat duodenum is not dependent on nitric oxide-induced changes in blood flow.

Mild irritation of the rat duodenum enhances mucosal resistance to acid via a prostaglandin-mediated mechanism. Prostaglandins increase mucosal blood flow, but it is not known whether such changes in blood flow significantly contribute to adaptive cytoprotection. We induced blood flow changes by manipulating the arginine-nitric oxide pathway, which is independent from prostaglandin synthesis, and determined the resulting effects on the cytoprotective response. In anesthetized rats, we tested the effects of intraduodenal infusion of mild acid on duodenal blood flow and on the prevention of mucosal damage by subsequent strong acid in control, indomethacin-pretreated, and NG-nitro-L-arginine-pretreated rats (NG-nitro-L-arginine inhibits the nitric oxide synthase). Additional experiments tested the effects of the prostaglandin analogue 16,16-dimethyl-prostaglandin (PG) E2 or sodium nitroprusside (nitric oxide donor) on duodenal blood flow and on mucosal protection against acid. Exposure of the duodenal mucosa to mild acid increased duodenal blood flow and mucosal resistance to acid. Instillation of 16,16-dimethyl-PGE2 also increased blood flow and mucosal resistance to acid. However, sodium nitroprusside increased blood flow without increasing mucosal resistance to acid, and NG-nitro-L-arginine inhibited the change in blood flow induced by acid while preserving the adaptive cytoprotection phenomenon intact. In conclusion, adaptive cytoprotection of the duodenal mucosa appears to be independent of changes in blood flow.

Effect of Pinellia ternata tuber on the efferent activity of the gastric vagus nerve in the rat

Effect of intraduodenal infusion with the hot aqueous extract of Pinellia ternata tuber on the efferent discharges in the gastric branch of the vagus nerve was observed in the anesthetized rat. The infusion of the extract in doses of 2–150 mg per animal (c.a. 300 g, b.wt.) resulted in a dose-related increase in efferent activity of the vagal gastric nerve. The enhancement of the nerve activity following administration of 150 mg of this substance lasted longer than 90 min. It was observed that the suppressive effect on vagal gastric activity due to apomorphine and copper sulfate was antagonized by prior administration of the extract. From these observations it is suggested that Pinellia tuber acts as a facilitatory agent on gastric function.