Pyloric Pouch Research Articles

Feather-Eating In Grebes: A 500-Year Conundrum

ABSTRACT Grebes are unique among birds in ingesting their own feathers. This behavior and the subsequent ejection of feathers as pellets have long puzzled ornithologists, who have tended to treat feather-eating and pellet-casting as independent behaviors rather than as complementary components of the digestive process. The diet of many grebes, including those with the most ancestral traits, is dominated by small invertebrates whose exoskeletons are resistant to digestion. Most birds eat grit to mechanically break down hard foods. Not so with grebes, which are chemical digesters. Feather-eating performs two main functions. The first is to retain food until it is fully digested; this is accomplished by a large feather bolus in the gizzard. The second, provided by a distinct group of feathers in the pyloric pouch, is to filter undigested or indigestible items from entering the intestine. Some of the gizzard bolus is probably regurgitated nightly, but the process is incomplete and undigested food can persist ...

Augmentation of Gastric Secretion by Cooling the Mucosa of Heidenhain Pouches

In an earlier paper (1) we have described an augmentation of acid and pepsin secretion from both innervated gastric mucosa and a Heidenhain pouch following cooling of the mucosa of an innervated pyloric pouch. β-Adrenergic receptors seem to play a part in this. Debas et al. (2, 3) have described vagally mediated pyloro-oxyntic reflexes which result in elevations of blood gastrin and/or acid secretion.In our first series of experiments cooling a Heidenhain pouch in animals with a gastric fistula did not augment pentagastrin-stimulated secretion from the fistula; on rewarming the pouch, however, the fistula secretion was significantly diminished (1). The data reported here are a reexamination of this phenomenonMethods. The animals used were five dogs with Heidenhain pouches, four of which in addition had innervated antral pouches of the Pavlov type, and finally six animals which 18 months previously had had their left gastric, right gastroepiploic arteries and accompanying nerves ligated and cut. Three of t...

Procedures of value for the prevention and cure of dumping after vagotomy and pyloroplasty

There is no question that vagotomy with pyloroplasty is a satisfactory operation for the treatment of peptic ulcer disease of both the stomach and duodenum. The poor results are due to incomplete vagotomy and the variations in the size of the pyloric canal after Heineke-Mikulicz pyloroplasty. Recurrent ulceration may occur if the vagotomy is incomplete, and dumping may occur if the pyloroplasty results in a large pyloric canal. A large pyloric pouch with a lumen admitting two and a half to three fingers was found at operation in four patients with severe manifestations of the dumping syndrome. Their symptoms were lessened after reconstruction of the pylorus so that the lumen admitted only one finger. It is our belief that anterior hemipylorectomy is a simple and safe operation and produces little or no deformity of the pylorus. It has a built-in limitation as to the size of the lumen. The postcibal symptoms encountered in our rather limited experience (fifty-one cases) with a short follow-up period, were mild and transient. They were, however, in keeping with the findings of Beattie, Holt and Lythgoe, and others [11,12]. In conclusion, we believe that the use of an anterior hemipylorectomy, instead of Heineke-Mikulicz or other types of pyloroplasty, will result in a decreased incidence of dumping after vagotomy. We also believe that in patients with severe dumping syndrome after vagotomy and pyloroplasty, reconstruction of the pylorus should be performed before more formidable procedures are attempted.

Effect of acid in pyloric pouch on response of fundic pouch to injected gastrin.

In dogs, the acid response of a denervated fundic pouch to irrigation of an isolated pouch of the pyloric gland area with 0.5% acetylcholine was reduced by 87% when the pH of the irrigating solution was lowered from 7 to 1.3. In the same dogs, gastrin extract was given by continuous intravenous injection, the isolated pyloric pouch being irrigated alternately with 0.1 n NaHCO3 and 0.1 n HCI. No significant difference in acid response of the denervated fundic pouch was observed during acidification as compared to alkalinization. These findings support the hypothesis that acidification of the pyloric gland area prevents release of gastrin and provide further evidence against the view that acidification causes the release of an inhibitory humoral agent.

Role of the vagus nerve in the second phase of gastric secretion

This work was conducted on 4 dogs esophagotomy and gastric fistula, isolated Pavlov's pouch, gastric fistula and Heidenhain's pouch, fistula of the stomach and isolated gastric pouch made of pylorus), in which one of the vagus nerves was enclosed into a cuff on the neck, and the other divided. As shown by experiments, the compression of the cuff by a force a little over 120 mm Hg provokes a block of the vagus conductivity, which may be estimated by the acceleration of the pulse and the appearance of Horner's syndrome. This excludes the first and the second phases of the gastric secretion, as well as secretion provoked by stimulating the mucous membrane of the isolated pyloric pouch.

Insulin hypoglycaemia and gastric motility in the sheep.

1. The effect of insulin hypoglycæmia on the motility of the abomasum and rumen has been studied in three sheep prepared with permanent fistulæ of these organs and in a lamb with a denervated pyloric pouch.2. These experiments have shown that in the sheep, as in the dog and man, the injection of insulin after an initial inhibitory period causes increased gastric motility as a direct consequence of the fall in blood sugar.3. The effect is dependent upon increased activity of the vagus nerves, since it does not occur in the denervated (vagal) stomach pouch and is inhibited by atropine.4. It is therefore probable that in the sheep, as in dog and man, hypoglycæmia acts centrally to excite vagal discharge.5. The absence of a gastric secretory response to insulin in the ruminant suggests therefore that the secretory cells, unlike the musculature, are not under central vagal control.

Nitrogen Content and Total Osmotic Activity of Gastric Juice.

Summary1. In general, pilocarpine-stimulated greater curvature gastric pouch juice has a lower osmotic activity, and high total nitrogen content than does histamine-stimulated juice. 2. Fasting juices show highly variable relations between total nitrogen content and osmotic activity. 3. Pyloric pouch fasting juice has in our experience very much higher total nitrogen content than does greater curvature pouch juice. The osmotic activity of the former is nevertheless hypertonic with respect to blood. 4. There appears to be a partial correlation between total nitrogen content and osmotic activity of gastric juice. 5. Calculated and observed osmotic activities are in reasonable agreement for six greater curvature pouch samples in which free acid was present. 6. Calculated values were 12 to 24 m.E./K. lower than the observed osmotic activity values for three pyloric pouch juices without free acid. It is suggested that part of the deficit results from neglecting in the calculation the contribution of the nitrog...

THE ACID-BASE COMPOSITION OF GASTRIC SECRETIONS

The chief inorganic factors in secretions obtained from isolated pouches constructed in the fundus and in the pyloric antrum of the cat's stomach were found to be chloride ion and fixed base. In a series of samples obtained from the fundic pouch, chloride ion was approximately stationary at 165 cc. 0.1 N per 100 cc. During digestion of food in the stomach, secretions from the pouch contained fixed base in amounts varying considerably from an average of 47 cc. 0.1 N per 100 cc. Material allowed to remain in the pouch after the completion of food digestion in the stomach showed an increasing content of fixed base, to as much as 140 cc. 0.1 N per 100 cc. A stationary total ionic content of secretions of the fundus is thus seen to be sustained by the chloride ion concentration, and changes in hydrogen ion concentration to be caused by variation of fixed base. The differing amounts of fixed base found are regarded as probably due to admixture of a mucous secretion with the juice from the fundic glands. The alkaline secretion taken from a pyloric pouch contained fixed base in excess of chloride ion. Variation of fixed base in the secretions from the fundic pouch were found to be referable to change in sodium content, the smaller factor, potassium, remaining approximately constant at about the value found in material from the pyloric pouch. This suggests that the mucous secretion of the fundus has the same composition as that produced by the pyloric antrum. These data will serve to explain the extensive withdrawal of fixed base, as well as of chloride ion, from the blood plasma in the presence of circumstances causing a continued loss of stomach secretions.

On the influence of gastric section on gastric secretion.

Resection of the pyloric end of the stomach is followed by a diminution in the hydrochloric secretion of the stomach. Circumscising the stomach in the pyloro-fundic region through the serous, muscular, and submucus coats of the gastric wall, or the excision of an annular segment from the wall of the stomach in this region, does not appear to be followed by a persistent fall in the gastric acidity, but by such relative decrease in acidity as can be demonstrated after other intra-abdominal operations. When these two procedures are combined, by dividing the pyloric end from the fundic portion of the stomach, and the pyloric part is left in the abdomen (See preceding paper) it appears that the pyloric pouch, thus created, continues to secrete acid.From these observations, it appears (a) that the pyloric portion is active in secretion (as it is generally agreed to be in motility); (b) that this secretory function continues after the section of vagal or vago-sympathetic nerves incorporated within or running upo...

Observations on the isolated pyloric segment.

The technic of isolating the pyloric segment from the remaining portion of the stomach in the dog was as follows: Anterior gastroenterostomy was performed between the fundus and jejunum 25 cm. aboral of the pyloric sphincter. The stomach was divided through two planes: first, through the sphincter pylori and second, through the pyloro-fundic region. The pyloric end of the intermediary segment thus created was brought into the wound as a fistula, while the other three cut ends were closed. By this means a closed pyloric pouch of stomach was established, communicating only with the skin surface of the animal. By means of the gastrojejunostomy the animal was fed and kept alive. (See diagram of experiment No. 1.) Five experiments were carried out according to this technic. Each animal lived from 10 days to 4 months, or long enough to determine (1) the acidity of the pyloric segment under the above experimental conditions, (2) the effects of acetylcholin, pilocarpin, and adrenalin respectively, upon the secretion of the pyloric segment, (3) the motor function of the residual stomach, and (4) the histology of the fundic and pyloric mucosae. The conclusions were as follows : (1) The reaction of the secretion from the pyloric segment was in every instance strongly acid in terms of litmus. (2) Acetylcholin and pilocarpin produced no appreciable increase in the amount or variation in the acidity of the pyloric secretion. Pilocarpin appeared to be followed by a more mucoid secretion. The adrerialin administration was followed by a distinct decreax in the amount of pyloric secretion. (3) The residual stomach emptied within 2½ hours through the gastrojejunostomy, in terms of the barium meal and X-ray. (4) Chief cells predominated in the vestibular portion, the aboral end of the body of the stomach, and parietal cells in the juxtapyloric mucosa.

OBSERVATIONS ON THE ISOLATED PYLORIC SEGMENT AND ON ITS SECRETION

1. The operative methods for isolating the pyloric segment and forming it into a pouch, are described.2. The secretion of the pyloric pouch is viscid, slightly alkaline and definitely proteolytic.3. The proteolytic action of the pyloric juice is not due to bacterial contamination, nor to the inclusion of peptic cells in the wall of the pyloric pouch, but to the presence of a ferment.4. The ferment secreted by the mucoid cells of the pylorus is only 1/25 as active as pepsin secreted by the peptic cells of the fundus, and has no associated rennin action.