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[On gastric corpus-pyloric antrum inhibitory reflexes (author's transl)].

Twenty eight adults dogs fasted over night were used under Nembutal anesthesia. The influences of distension of the pouch which was made on gatric corpus on the motility of gastric pyloric antrum were investigated. The following results were obtained. 1) Any changes were not observed on the motility on gastric pyloric antrum by distension of gastric corpus pouch by a pressure of 20 mmHg, but a stepwise elevation of the lumen pressure of the pouch from 50 mmHg to 100 mmGh, elicited a remarkable relaxation of the tone and inhibition of motility of the pyloric antrum. These inhibitory responses were not abolished by the bilateral cervical vagotomy or by the bilateral splanchnicotomy respectively, but these inhibitory reflexes were disappeared completely after the transection of both extrinsic nerves. 2) The inhibition of motility of gastric pyloric antrum were also elicited by the electric stimulation of the central cut end of vagal branch or of splanchnic branch which innervated the gastric corpus respectively. 3) It may be concluded that the reflex pathways of the gastric corpus-pyloric antrum inhibitory reflexes involve not only in vagus nerves but also in splanchnic nerves.

Animals

The role of the pyloric antrum and Hofmeister value in the development of the chronic gastric mucosal reaction.

A limited chronic gastric mucosal reaction (CGMR) develops when duodenal contents enter the stomach with an intact pyloric antrum. However, after antrectomy the same stimulus leads to a widespread CGMR. The pyloric antrum, therefore, seems to influence the development of the CGMR. A Hofmeister valve included in a Polya gastrectomy does not prevent the development of the VGMR, presumably because reflux is not prevented.

Animals

The inhibitory influence of the pyloric antrum on gastric secretion in dogs.

The effect of the pyloric antrum and of subsequent vagotomy on the secretory responses of an innervated or a denervated gastric pouch in the dog to histamine and pentagastrin was determined. The increased sensitivity of the gastric pouch to stimulation after these procedures is in keeping with the concept that an inhibitory reflex is concerned with the control of acid gastric secretion.

Animals

Surgical removal of the pyloric antrum in weanling rats.

A method was devised for surgical removal of the pyloric antrum in 3-week-old rats. Contrary to published experiences with older rats, it was found that ligation of right and left gastroepiploic arteries was not necessary in young animals. Erythrocytes and fluids were routinely administered postoperatively, and recovered animals were denied access to water and food for 2 and 3 days, respectively. When the rats were fasted overnight prior to surgery, the recovery rate was 87% (27 of 31 attempted). Surgical sites were intact and showed minimal adhesions 2 months later. When overnight fasting was omitted, only 57% survived (8 of 14 attempted), because extensive manipulations were necessary to remove gastric contents, and this often produced shock.

Animals

Effect of denervation of pyloric antrum on the gastric secretory response to food.

The effect of selective denervation of the pyloric antrum on secretory response to three types of food was determined in 3 dogs with innervated and 4 with denervated stomach pouches. With the antrum in situ this procedure has surprisingly little effect on the total meal responses in innervated pouches, on the variation in response induced by altered buffering capacity of the meals, or on the effect of subsequent vagotomy. However, the antrum appears less sensitive to local stimuli after denervation, as evidenced by the reduced meal response from the denervated indicator pouch after denervation of the antrum.

Animals

Immunochemical studies of the endocrine cells of the gastrointestinal tract. I. The use and value of peroxidase-conjugated antibody techniques for the localization of gastrin-containing cells in the human pyloric antrum.

This paper describes and immunochemical localization of gastrin-containing endocrine cells in the human pyloric antrum using antibodies conjugated to horseradish peroxidase. With pre-fixed cryostat sections, a distinct clear-cut staining of gastrin-containing cells can be obtained either by direct or indirect single stain procedures, but may cells containing endogenous peroxidase activity also stain. In order to abolish staining due to endogenous peroxidase, sections were pretreated with a number of inhibitors prior to incubation in immune sera, but the inhibitors used appeared to interfere with the antigenicity of the gastrin molecule since subsequent immunochemical localization was impossible. The application of a double-staining technique, however, allowed us to distinguish easily between those cells which contained endogenous peroxidase and those on to which labelled antibody had been adsorbed. No labelled cells were found in post-fixed cryostat sections of fresh-frozen tissue. The technique is of value because preparations are permanent, a fluorescence microscope is not required, and the same technique can be adapted for use with the electron microscope.

Animals

Control of gastric emptying: interaction of the vagus and pyloric antrum.

Gastric emptying of liquids and solids was evaluated in ten dogs with gastric fistula before and after either truncal vagotomy, antrectomy, or pyloroplasty. In subsequent operations, the vagotomy group underwent either antrectomy or pyloroplasty, and the antrectomy and pyloroplasty groups were vagotomized. Vagotomy significantly inhibited the emptying of both liquids and solids (p less than 0.001) when the pyloric antrum was intact. When the antropyloric mechanism was removed by antrectomy, the effect of vagotomy was to accelerate the emptying of liquids (p less than 0.05) but to impair the emptying of solids (p less than 0.001). When the pylorus was destroyed by pyloroplasty, vagotomy markedly accelerated the emptying of liquids but had little effect on the emptying of solids. Neither antrectomy nor pyloroplasty had any significant effect on the emptying of solids. Pyloroplasty caused minor acceleration of emptying of liquids while antrectomy had no effect.

Animals

The gastrin-producing cells in tissue cultures of the rat pyloric antrum.

Tissue culture methods were used to study the gastrin-producing cells isolated from the pyloric antral mucosa of rats. Cultures were maintained for up to 7 days. Gastrin cells were identified by means of immunofluorescent and unlabeled antibody-enzyme techniques. The tissue culture medium was monitored for basal gastrin secretion. In addition, stimulation of gastrin release was achieved by the use of dibutyryl cyclic-AMP and theophylline. This is the first report of the successful application of tissue culture methods to the functional study of antral gastrin cells. The procedure has proven to be useful in assessing the mechanisms of gastrin secretion.

Adenosine Monophosphate

The G cell population of the pyloric antrum of the cat.

The method used in this study to quantify the G cell population of the cat is similar to the technique used for measuring the parietal cell mass in the stomach of rats and man. The method may be used on the human antrum. Mucosal sampling technique and immunofluorescence methods are described. The method is reproducible. G cell distribution in the antrum was not uniform and the highest concentrations were found along the lesser curvature. The G cell population was 10.27, 12.66, 12.87, 12.88 and 15.42 million cells (mean 12.8 x 10(6)) per antrum in each of the five cats studied.

Animals

Acute multiple gastric ulcers in the pyloric antrum.

Acute prepyloric hemorrhagic erosions occasionally progress to symmetrical ulcers. Cytomegalic inclusion bodies were frequently seen, a history of alimentary allergens, excessive alcohol intake or coffee drinking was common. Hyperchlorhydria which decreased spontaneously was found in 89% during the acute attack.

Acute Disease

The effect of fixation conditions on the ultrastructural appearance of gastrin cell granules in the rat gastric pyloric antrum.

The ultrastructural appearance of gastrin cell (G cell) granules was studied after different fixation procedures. When the pH of prefixation was varied there was greater preservation of the electron density of granule cores after acidic (pH 5.0 and 6.0) than after neutral or alkaline (pH 7.0 and 8.0) prefixation. Increasing duration of prefixation at pH 7.3 resulted in progressive loss of electron density of the granule core with swelling and occasional rupture of the limiting membrane. In tissues where most granules had been rendered electron lucent by fixation, those granules remaining dense cored were preferentially located close to the Golgi zone. These findings indicate that the electron density of G cell granules is profoundly affected by conditions of fixation, and that immature granules are more resistant to loss of core density than mature granules. They also suggest that the gastrin granule in vivo, like other polypeptide granules, may have a "solid", osmotically inactive core.

Animals

[Mechanism of the contracting actions of K, acetylcholine and Ba and of the antispasmodic actions of Cd and Mn in the pyloric antrum strip of the rat, with special reference to their relationship to Ca].

Action mechanisms of the contractile agents, K ACh and Ba and of the antispasmodics, Cd and Mn were investigated. The contractions by K,ACh and Ba are exponential in shape, but consisted of phasic contraction (PC) and the subsequent tonic contraction (TC). PC by K and ACh are inititated by the release and the passive influx of Ca, whereas the PC by BA is due to the release of Ca. On the other hand, TC by these three agents is maintained by the active influx of Ca requiring energy. Since only the contraction by Ba remains constant in Ca(-) bath solution, it is assumed that the direct stimulation to muscle contractile elements without the mediation of Ca mobilization is also partly related to the contracting mechanism of Ba. Storage sites of Ca in the cell membrane of this preparation are distinguished into three divisions, the first, the second and the third, which contains loosely-, less lossely-, and tightly-bound Ca, respectively. K releases Ca to elicit contraction from the first divisions, ACh does so from the first and the second divisions, and Ba does so from all of the three divisions. The following assumption was obtained on the antispasmodic action of Cd and Mn, on the basis of the influence of Ca removed from bath solution and of addition of high K to bath solution and the analysis with concentration-action curves. The antispasmodic mechanism Cd and Mn is due to inhibition of cell membrane (competitive inhibition of influx and then release of Ca and subsequently competitive and non-competitive inhibition of influx and release of Ca) followed by the non-competitive inhibition of muscle contractile system, with the increase of dosage.

Acetylcholine