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W Y Chey

Publications and source records attributed to W Y Chey.

At least 163 records · Page 9Linked to original sources
PubMed1981

Mapping of motilin-immunoreactive neurons of the rat brain.

Motilin immunofluorescence was observed in the rat brain by means of N- and C-terminally directed antisera. A detailed mapping of the localization of motilin-like immunoreactive neurons in the rat forebrain is presented. Colchicine pretreatment revealed many cell bodies in the mediobasal hypothalamus. A small number of cells were observed in the organum vasculosum lamina terminalis (OVLT) region. A rich innervation of varicose fibers was observed in the median eminence and OVLT. Fibers of varying densities were observed in the preoptic area, nucleus interstitialis stria terminalis, hypothalamic nuclei, basal hypothalamus, amygdala, mammillary doby and central gray. The localization of these neurons suggests that motilin, like other brain peptides serves a variety of functions including neuroendocrine regulation.

Amygdala↗
PubMed1981

The release of biologically active secretin-like immunoreactivity into duodenal lumen of dogs.

1. Immunoreactive secretin in the duodenal contents was determined in four conscious and four anaesthetized dogs in which hydrochloric acid (0.1 N) was infused into the duodenum at 2.2 ml./min. In the conscious dogs, immunoreactive secretin concentration in duodenal juice increased from 5-7 to 40-60 ng/ml. after infusion of HCl. In anaesthetized dogs, luminal immunoreactive secretin concentration increased from 2-3 to 12-16 ng/ml. after acid infusion. In both groups of dogs, a 20- to 30-fold increase in the total output of luminal immunoreactive secretin was observed. 2. Duodenal juice collected from anaesthetized dogs after diversion of both bile and exocrine pancreatic secretion was found to be the only source of luminal immunoreactive secretin. No immunoreactive secretin was found in either bile or pancreatic juice. 3. Gel filtration of the duodenal juice on a Sephadex G-50 column indicated that the immunoreactive secretin-like material in the duodenal juice possesses a molecular size similar to that of natural porcine secretin. 4. Immunoreactive secretin was partially purified from dog duodenal juice by chromatography on a SP-Sephadex column and found to be capable of stimulating pancreatic bicarbonate and water secretion in dogs.

Animals↗
PubMed1981

Secretin is an enterogastrone in the dog.

To determine the physiological significance of secretin on gastric secretion, effects of normal rabbit serum (control) and rabbit antisecretin serum (anti-S) on meat meal-stimulated gastric secretion of acid and pepsin from vagally innervated fundic pouches were studied in four dogs with gastric fistulas. The intravenous administration of control serum did not affect the postprandial rise in plasma secretin concentration, whereas intravenous anti-S virtually eliminated the circulating plasma secretin. Both plasma gastrin concentration and acid output following intravenous anti-S were significantly greater than those following intravenous control serum. However, pepsin outputs in the two groups of experiments were not significantly different. In the same dogs in the fasting state, during intravenous infusion of secretin in doses of 0.06 and 0.125 U . kg-1 . h-1, the acid output stimulated by intravenous human synthetic gastrin in a dose of 0.25 micrograms . kg-1 . h-1 was significantly less than that during intravenous saline. The studies indicate that secretin in a physiological dose can inhibit postprandial release of gastrin and gastric secretion of acid, and thus secretin is an enterogastrone in the dog.

Animals↗
PubMed1981

Gastric and small intestinal myoelectric dysrhythmia associated with chronic intractable nausea and vomiting.

We describe a patient with symptoms of severe nausea, vomiting, epigastric bloating and pain, and marked weight loss due to a gastrointestinal motility disturbance. Motility abnormalities were characterized by uncoordinated high pressure (as high as 300 mm Hg) contractions and uncoordinated interdigestive motor complexes in the duodenum and small intestine, and tachygastria often associated with tachyarrhythmia in the gastric myoelectric activity recordings. Uncoordinated interdigestive myoelectric complexes again were found in the duodenum and small intestine. These abnormal myoelectric activities observed in the in-vivo study were confirmed in the in-vitro study. After distal hemigastrectomy and gastrojejunostomy, the symptoms of nausea, vomiting, and epigastric pain decreased considerably. Thus, the motility abnormality found in the study appears to be responsible for the symptoms described. This is probably a new clinical entity. The importance of manometric and myoelectric study of a gastrointestinal motility for unexplained nausea and vomiting is emphasized.

Adult↗
PubMed1981

Effect of sodium oleate on plasma secretin concentration and pancreatic secretion in dog.

The effects of sodium oleate and triglyceride infused into the duodenum of dogs with chronic pancreatic fistulas on pancreatic secretion and plasma immunoreactive secretin were investigated. The responses were compared with those following intravenous secretin infusions. Oleate markedly increased pancreatic water and bicarbonate secretion in a dose-related fashion, and these increases were accompanied by a small, but significant rise in the level of circulating immunoreactive secretin. No change in pancreatic secretion or in plasma secretin level was observed by the administration of triglyceride. Comparison of the bicarbonate response after oleate infusion with that after secretin administration suggests that the pancreatic stimulatory effect of intraduodenal sodium oleate is mediated to a major extent by the release of endogenous secretin.

Animals↗
PubMed1981

Role of secretin on postprandial gastrin release in the dog: a further study.

To determine the physiologic role of secretin on gastric secretory function, the effects of secretin in a physiologic dose on gastrin release and gastric acid secretion were studied in four dogs with vagally innervated fundic pouches. Three sets of experiments were performed in each dog: (1) meal alone, (2) meal after intravenous cimetidine to suppress acid secretion and release of secretin, and (3) meal after intravenous cimetidine with simultaneous intravenous secretin, 0.03 clinical unit (CU)/kg-hr. A significant increase in plasma secretin concentration occurred after ingestion of a meal. The postprandial increase in the secretin level was abolished by intravenous cimetidine 200 mg, whereas intravenous cimetidine resulted in a marked increase in the postprandial plasma gastrin concentration which was significantly greater than that after a meal alone. A plasma secretin level comparable to that of the postprandial period could be achieved in the same fasting dogs by intravenous secretin, 0.03 U/kg-hr in 2% dog albumin solution. The postprandial plasma gastrin concentration and acid secretion following intravenous cimetidine were significantly decreased by simultaneous intravenous secretin at a dose of 0.03 U/kg-hr. The observations indicate that secretin plays a significant role in the regulation of release of gastrin and gastric secretion of acid in the postprandial state in dogs.

Animals↗
PubMed1980

A simplified procedure for preparing innervated gastric pouches.

Conventional innervated gastric pouches can be technically difficult to construct, and fistula formation between the pouch and the main stomach cavity is a common problem. This paper describes the method of construction of a small pouch on the lesser curvature (LC pouch) which we have found to be relatively free of these difficulties. Compared with the Pavlov-type pouch, this pouch gives a stronger acid secretory response to a meat meal. Furthermore, the acid secretory response was prompt to insulin hypoglycemia and sham feeding.

Animals↗
PubMed1980

Radioimmunoassay of secretin. A critical review and current status.

The radioimmunoassay methods of secretin are reviewed with respect to production of antibody, preparation of radioactive tracers, and effect of plasma interference. The major difference in the secretin assay methods resides in handling plasma interference. Thus the assay sensitivity decreased markedly when the assay was conducted by diluting plasma samples. When the assay was conducted by compensating for plasma interference with homologous hormone-free plasma, the effect of plasma interference was greatly reduced, leading to a more sensitive assay. However, this method probably can not obtain consistent results with plasma samples collected under various experimental conditions. The method is still subject to considerable desensitization and assay variation. On the other hand, the elimination of plasma interference before assay results in the most sensitive secretin assays capable of detecting consistently a significant postprandial rise in plasma secretin level. It is concluded that a sensitive, validated secretin radioimmunoassay should be one that is capable of detecting increments of plasma secretin in response to doses of intraduodenal acid at 0.055 mEq/min or lower and intravenous administration of exogenous secretin at 0.03 CU/kg/hr with concomitant stimulation of pancreatic bicarbonate and water secretion. With a sensitive and accurate radioimmunoassay for secretin, it is now possible to further investigate the physiology and pathophysiology of secretin.

Acids↗
PubMed1980

24-Hour plasma secretin level and pancreatic secretion in dog.

Plasma secretin concentrations were determined and duodenal pH was recorded continuously for a period of 24 hours after ingestion of a meal in 3 dogs with gastric cannula and duodenal cannula and in 4 dogs with pancratic fistulae. The mean plasma secretin concentration increased significantly after a meal and it remained elevated for the first 12-hour period (peak at 30 min). Duodenal pH frequently decreased below 4.5 during the first 12-hour postprandial period, but it remained above 5.0 during the second 12 hours. Pancreatic secretion peaked during the first hour of meal ingestion and remained elevated until the end of 12 hours. The increased plasma secretin level in pancreatic fistula dog during the postprandial period was significantly greater than that of duodenal cannula dog, but the trends of increase in the secretin levels were quite identical. The present study indicates that: (1) plasma secretin concentration increases significantly within 30 min after a meal and remains increased during the first 12-hour period, (2) duodenal pH frequently decreaded below 4.5 during the same 12 hours but more frequently during the first 6 hours, and (3) a significant increase in pancreatic water, HC03- and protein occurred during the same time period.

Animals↗
PubMed1980

Enkephalin inhibits the release and action of secretin on pancreatic secretion in the dog.

1. Pancreatic bicarbonate and protein secretion as well as immuno-reactive plasma secretin concentration in response to a meal, duodenal acidification and exogenous secretin or octapeptide of cholecystokinin (OP-CCK) have been measured following administration of methionine-enkephalin in chronic pancreatic fistula dogs. 2. Methionine-enkephalin inhibited pancreatic responses to both exogenous hormones (secretin and OP-CCK) and to endogenous hormones released from the gut by food or duodenal acidification. 3. Naloxone, a potent opiate receptor antagonist, partly prevents this methionine-enkephalin-induced inhibition of pancreatic secretion suggesting that this effect might be mediated by opiate receptors. 4. The inhibitory effect of methionine-enkephalin on pancreatic response to endogenous stimulants was more pronounced than that to exogenous hormones and was accompanied by a significant reduction in plasma immuno-reactive secretin concentration. 5. This study indicates that methionine-enkephalin inhibits pancreatic secretion, at least in part, by suppressing the release of the intestinal hormones stimulating the exocrine pancreas.

Animals↗
PubMed1980

Effects of a meal and gut hormones on plasma motilin and duodenal motility in dog.

Cyclic increases in the motilin level that coincided with phase III activity of interdigestive myoelectric activity of interdigestive myoelectric activity of the duodenum produced varied plasma motilin concentrations in a fasting dog. Ingestion of a meat meal not only abolished the cyclic increases in motilin concentrations, but also resulted in a significant decrease in the plasma motilin level that was accompanied by phase II-like myoelectric activity of the duodenum, a so-called digestive pattern. Although intravenous gastrin or cholecystokinin octapeptide (CCK-OP) or a combination of gastrin, CCK-OP, and secretin converted the interdigestive myoelectric activity to a digestive pattern, the cyclic increases in plasma motilin levels coulc not be changed by these hormones. This study indicates that a cyclic increase in motilin concentration occurs during the interdigestive period, but not during the digestive period. Instead, a significant decrease occurs. These changes in plasma motilin levels do not appear to be produced by three known gut hormones that are released after ingestion of a meal.

Animals↗
PubMed1980

Physiological doses of secretin do not stimulate acute insulin release.

To study the effect of physiological increments in plasma secretin concentrations on basal and glucose-stimulated insulin release, bolus iv glucose injections (5 g) were given to normal weight volunteers (less than 108% ideal BW) before, during, and 30 min after a secretin infusion at a rate of 0.125 U/kg.h, raising mean plasma immunoreactive secretin to 35.5 +/- 8.3 pg/ml. Acute insulin responses to glucose were unaffected during or after the secretin infusion. Furthermore, when plasma glucose was elevated to postprandial levels (128--165 mg/dl), a similar secretin infusion also failed to alter acute insulin responses. In addition, no changes in basal glucose or insulin levels were found when endogenous secretin concentrations were increased by intraduodenal acid infusion. Thus, increases in plasma secretin to concentrations seen in the postprandial state fail to alter acute insulin secretion. It is unlikely that secretin plays any role in the intestinal stimulation of insulin secretion.

Adult↗
PubMed1980

Actions of motilin on gastrointestinal motility and plasma immunoreactive motilin concentration in interdigestive and postprandial states.

Among biological actions of motilin on gastrointestinal motility, its action to induce phase III, activity front, of interdigestive myoelectric complex (IMC) appears to be of physiological significance. Synthetic motilin in a dose as little as 0.06 microgram/kg-h was shown to induce phase III in dog. A cyclic increase in fasting plasma immunoreactive motilin concentration (PIMC) occurred in phase III in dog and in a later part of phase II in man, suggesting strongly that there is an intimate relationship between cyclic increase in fasting PIMC and IMC. The observation also suggested that gastric acid secretion increases in phase II and phase III of IMC. The cyclic increase in the acid secretion may be related to a coincidental cyclic increase in PIMC. Ingestion of a meat meal results in a significant decrease in PIMC and abolishes the cyclic increase in PIMC, while IMC changes to digestive pattern after a meal. The significant decrease in PIMC is not attributed to the 3 known gut hormones including gastrin, octapeptide of CCK and secretin.

Animals↗
PubMed1980

Reflux esophagitis: effect of oral bethanechol on symptoms and endoscopic findings.

We ascertained the effectiveness of oral bethanechol on symptoms and endoscopic evaluation of reflux esophagitis in a double-blind controlled study. Forty-four patients were treated with either 25-mg bethanechol tablets or placebo, each given four times daily for 4 weeks, in addition to conventional medical therapy. Both therapies significantly decreased symptoms as well as endoscopic lesions; however, endoscopic improvement was significantly better in the bethanechol-treated group. Bethanechol therapy resulted in complete endoscopic healing in 10 of 22 cases, whereas only three of 22 patients in the control group had such healing. No worsening of endoscopic lesions was seen in either group. Our study indicates that bethanechol is an effective drug offering advantages over conventional antacid therapy in the treatment of reflux esophagitis.

Administration, Oral↗
PubMed1980

Motilin.

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Action Potentials↗