Search PubMed⌕ Search

Biomedical subjects

W Y Chey

Publications and source records attributed to W Y Chey.

At least 127 records · Page 7Linked to original sources
PubMed1986

Motility abnormality in dogs with gastrojejunostomy.

Motility related to gastrojejunostomy were studied in seven dogs which were prepared with a gastric cannula and platinum electrodes placed in the antrum, duodenum, jejunum and ileum. Five dogs were equipped with gastrojejunostomy at the time of electrode implantation and the two remaining dogs were used as control. Myoelectric activity recorded revealed several abnormal findings and occasionally spike activity occurred simultaneously in the duodenum, jejunum and ileum or it retropropagated from lower ileum to reach the stomach. The study suggests that the dyspeptic symptoms observed in patients after gastrojejunostomy may be associated with similar motility abnormalities as observed in these dogs.

Animals↗
PubMed1985

Rapid, small-scale preparation of gastrointestinal hormones by high-performance liquid chromatography on a C18 column.

A rapid reversed-phase high-performance liquid chromatography method was developed for the isolation of small quantities of biologically active gastrointestinal hormones, using a Varian MCH-10 C18 column. Biologically active secretin was isolated from contamination with other hormones, including cholecystokinin, gastrin, motilin, and vasoactive intestinal polypeptide, from samples of the acid perfusate of canine duodenum and from the crude acetic acid extract of canine antral mucosa containing less than 100 picomoles of secretin. The method also appeared to be suitable for the isolation of cholecystokinin octapeptide and motilin.

Animals↗
PubMed1985

Effects of exogenous secretin on pancreatic and biliary ductal and sphincteric pressures in man demonstrated by endoscopic manometry and correlation with plasma secretin levels.

An endoscopic manometric technique was used to investigate the effects of exogenous secretin on pancreatic duct, common bile duct, pancreatic duct sphincter, and bile duct sphincter pressures in 20 healthy volunteers. Synthetic secretin was infused intravenously at rates of 8.05, 16.1, 32.2, 64.4, 129, 258, and 516 ng/kg/hr, and plasma secretin concentrations were measured by a radioimmunoassay. Secretin produced a significant fall in peak and trough pancreatic duct sphincter pressures from basal values of 48.2 +/- 7.9 mm Hg (mean +/- SD) and 16.9 +/- 7.7 mm Hg, respectively, to 34.4 +/- 6.8 mm Hg and 11.2 +/- 5.8 mm Hg (P less 0.005), respectively, at a mean plasma secretin concentration of 16 pg/ml (during an infusion rate of 32.2 ng/kg/hr). Higher infusion rates had no additional effect. Pancreatic duct pressure became significantly elevated above basal (11.5 +/- 4.0 mm Hg) at the two highest secretin rates. Secretin had no effect on common bile duct or bile duct sphincter pressures. Plasma secretin concentrations were within the postprandial range during the lowest four secretin infusion rates. We conclude that secretin produces selective physiological relaxation of the pancreatic duct sphincter.

Adult↗
PubMed1985

Increased interdigestive pancreatic trypsin secretion in alcoholic pancreatic disease.

Previous studies have suggested that chronic alcohol consumption in man is associated with an increased secretion of pancreatic enzymes. Precise quantitation of the output of protein and trypsin in the interdigestive state has not been possible because of large variations and small volume of pancreatic juice. We utilized a multilumen, marker-perfused duodenal catheter to simultaneously monitor intraluminal pressures and collect mixed duodenal juice at the ligament of Treitz in five groups of patients: normal volunteers (group I), alcoholics without pancreatitis (group II), alcoholics who had recovered from acute pancreatitis (group III), alcoholics with chronic pancreatitis (group IV), and nonalcoholics who had recovered from acute pancreatitis secondary to biliary tract disease (group V). The output of trypsin and protein during 30 min of phase II and 60 min of CCK-OP 40 ng/kg/hr was determined in each group. The output of trypsin during phase II was 1.3 +/- 1.2 and 3.0 +/- 2.5 mg/kg/hr in groups II and III, respectively, compared to 0 +/- 0.1 in group IV (normal = 0.6 +/- 0.5). The outputs in group V were similar to normals. The output of protein during the interdigestive state was 15.7 +/- 13.7 mg/min in group III, compared to 4.5 +/- 3.6 in normals (group I). The duodenal contraction rate was 4.6 +/- 3.0 and 3.3 +/- 2.7 contractions/min in groups III and II, respectively (significantly greater than the normal rate of 2.2 +/- 1.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1985

Studies on mechanism of retching and vomiting in dogs. Effect of peripheral dopamine blocker on myoelectric changes in antrum and upper small intestine.

In five conscious dogs prepared with a gastric cannula and platinum monopolar electrodes in the antrum, duodenum, and jejunum, the effect of dopamine or copper sulfate on the myoelectric activity was studied. During phase I of interdigestive myoelectric activity, retching, and/or vomiting occurred in 1.6 +/- 0.2 (mean +/- SE) min after intravenous bolus injection of dopamine (50 micrograms/kg) or in 8.7 +/- 1.8 min after intragastric administration of copper sulfate (2%, 50 mg). Immediately prior to the retching and/or vomiting act, a group of disordered myoelectric activities occurred, including retrograde-moving trains of spike activity starting from the jejunum and the subsequent tachyarrhythmia in the antrum. These motility changes also occurred in the two anesthetized dogs so studied. Both the retching and/or vomiting act and the abnormal myoelectric activity which were induced by dopamine and by copper sulfate were prevented by intravenous administration of a peripheral dopamine blocker, domperidone, 5 mg, in 100% and 70%, respectively. Although domperidone could not prevent the retching and/or vomiting induced by copper sulfate in three of 10 experiments, it delayed the onset of vomiting from 8.7 +/- 1.8 to 14.5 +/- 5.3 min. A possible role of peripheral dopamine receptor on the motility disorders associated with retching and/or vomiting has been suggested.

Animals↗
PubMed1985

Duodenal acidification releases cholecystokinin.

We studied the effect of hydrochloric acid (HCl) in the proximal small intestine on release of cholecystokinin (CCK) and secretin and on exocrine pancreatic secretion in conscious dogs with gastric cannulas and modified Herrera pancreatic cannulas. Intraduodenal administration of HCl in a concentration of 50 or 100 mM at rates of 0.05, 0.1, 0.2, and 0.4 mmol/min significantly increased plasma concentration of CCK in a dose-dependent manner, whereas plasma gastrin levels decreased. The increased plasma CCK level paralleled a significant increase in pancreatic trypsin output. Plasma secretin concentration and pancreatic bicarbonate output also increased in response to the acid, and the increase was dependent on the acid loads delivered in the duodenum. Thus, in dogs, HCl in the duodenum releases both CCK and secretin to stimulate pancreatic secretion of bicarbonate as well as enzymes.

Animals↗
PubMed1984

Electric acupuncture stimulates non-parietal cell secretion of the stomach in dog.

Effects of acupuncture and electroacupuncture (EAP) on gastric secretion were studied in the interdigestive state of five conscious dogs prepared with esophagostomy and gastric cannulas. Both EAP and acupuncture without electrical stimulation produced significant increases in gastric secretion of bicarbonate and sodium. At the same time, a marked decrease in gastric secretion of acid was noted. EAP clearly demonstrated a greater effect on gastric secretion within these three parameters than did simple acupuncture. The fact that the effects of EAP and acupuncture on gastric secretion of bicarbonate and sodium were completely blocked by either a local anesthetic agent or anticholinergic agent indicates that gastric secretion involves a somatic afferent-visceral reflex mechanism in which a cholinergic nerve plays a role.

Acupuncture Therapy↗
PubMed1984

Development of isolated perfused whole stomach for motility study in rat and cat.

An isolated ex vivo perfused mammalian stomach preparation is an ideal model for the study of motility avoiding central nervous influence and circulating humoral factors. In this paper, we describe the technique of such preparation in two different species: rat and cat, and its implication for motility study. While the isolated stomach was perfused with Krebs-Ringer solution via celiac artery, motility of the antrum was recorded using an open-tip tube in rats and a bipolar platinum electrode and a strain gauge in cats. The spontaneous antral motility and its response to drugs, such as dopamine and domperidone proved that the preparation would be a useful model to study motility devoid of influences of the central nervous system and circulating humoral agents.

Animals↗
PubMed1984

The effects of sulfasalazine on human male fertility potential and seminal prostaglandins.

Fertility parameters of 10 men with chronic inflammatory bowel disease under treatment with sulfasalazine for at least 5 years were compared to those of 19 control subjects. Seminal parameters examined included ejaculate volume, sperm number and concentration, sperm motility index, sperm viability, pH, zinc concentration, prostaglandins E and F2-alpha, prolactin and 7 classes of sperm morphology. In addition, plasma concentrations of follicle-stimulating hormone, luteinizing hormone, testosterone and prolactin were noted. The data indicate that sulfasalazine therapy reduces semen quality and that this effect can be reversed upon removal from therapy. This reversal is independent of seminal prostaglandin concentrations.

Adult↗
PubMed1984

Potentiating effect of secretin on cholecystokinin-stimulated pancreatic secretion in dogs.

A possible potentiating effect of cholecystokinin octapeptide (CCK-OP) on the action of secretin on exocrine pancreatic secretion was studied in five dogs with gastric fistulas and modified Herrera pancreatic fistulas. Secretin in a dose, 2.45 pmol (0.03 clinical units) X kg-1 X h-1, that mimics the plasma secretin level in the postprandial state increased pancreatic bicarbonate secretion, but the increase was not statistically significant. CCK-OP in graded doses, 26.2, 52.5, 109, and 219 pmol (0.03, 0.06, 0.125, and 0.25 microgram) X kg-1 X h-1, given intravenously produced a significant increase in both bicarbonate and protein secretion, and the increase was dose related. The plasma concentrations of immunoreactive CCK during intravenous infusion of CCK-OP in doses of 26.2 and 52.5 pmol X kg-1 X h-1 were found to mimic the postprandial plasma concentrations of immunoreactive CCK in eight dogs. When CCK-OP in four graded doses was added to intravenous infusion of secretin, 2.45 pmol X kg-1 X h-1, the actual bicarbonate output at each dose level of CCK-OP was greater than the sum of the bicarbonate outputs produced by secretin alone and CCK-OP alone in a corresponding dose. Thus, we conclude that the action of secretin in a physiological dose that mimics the plasma level of secretin after a meal is potentiated by CCK-OP in a dose range that produces a plasma CCK-OP level comparable with that in the postprandial state and vice versa. The study indicates that, like secretin, CCK-OP is another necessary agent for pancreatic secretion of bicarbonate during digestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Non-gastrin secretogogue in ulcerogenic tumors of the pancreas.

In 18 patients with hypersecretion of acid, severe ulcer diathesis, and pancreatic islet cell tumor or hyperplasia, 14 had hypergastrinemia and 4 had normal plasma gastrin concentration. The neoplasms contained several gut peptides beside gastrin. The immunoreactive gastrin in the tumor extracts measured less than 7 ng/g, less than the amount previously reported. The extracts of each patient's tumor also contained a secretogogue other than gastrin that stimulated gastric acid secretion in rats. In addition, the plasma extracts of 2 patients also contained a secretogogue that stimulated acid secretion. After surgical resection of a recurrent metastatic tumor in 1 patient, basal acid secretion decreased from 13.9 to less than 1 meq/h, and the bioactivity of the plasma disappeared. These observations suggest the existence of a secretogogue that appears to be a protein in the pancreatic tumors of some patients with severe ulcer diathesis and hypersecretion.

Adenoma↗
PubMed1984

Study of electromechanical activity of the stomach in humans and in dogs with particular attention to tachygastria.

The relationship between electric and mechanical activities of the gastric antrum was investigated in both humans and dogs. In 2 patients, in whom platinum monopolar electrodes were implanted on the serosal surface of the antrum and a perfused manometric tube was placed in the stomach, the number of gastric contractions detected by manometry was only less than 50% of the pacesetter potentials accompanied by action potentials or second potentials. No contraction of the stomach was recorded by manometry when pacesetter potentials occurred without action potentials or second potentials. The relationship was further investigated in 11 anesthetized dogs prepared with implanted electrodes and sensitive ministrain gauges implanted on the serosal surface of the stomach and an intragastric manometric tube. In these dogs, phasic contractions were always recorded by the method using ministrain gauges although the electrical activity showed only PSPs without action potentials or second potentials. The manometry, however, could not recognize these phasic contractions. When the stomach was stimulated by bethanechol infusion through the splenic artery, as in the human stomach, the manometry detected less than 50% of gastric contractions detected by the strain gauge recording. The gastric dysrhythmia including tachygastria, tachyarrhythmia, and bradygastria was induced in 10 dogs by epinephrine, 100 micrograms X kg-1 X h-1, infused via the splenic artery. During the period of gastric dysrhythmia, the phasic contractions disappeared and no contraction associated with action potential could be observed. The phasic contractions reappeared as long as the PSPs occurred regularly in a frequency of 4-5 cycles/min during either the control period or during the period of epinephrine infusion. The epinephrine-induced gastric dysrhythmia was blocked or reversed to normal pacesetter potentials by intraarterial infusion of phentolamine. Our study suggests the following: (1) the pacesetter potentials not only pace and direct gastric contraction, but they may also play a role in the genesis of phasic contractions of the stomach, and (2) gastric contractions detected by sensitive strain gauges are not always recorded by the intraluminal manometry and, thus, gastric dysrhythmia may not be detected by the manometry in humans.

Action Potentials↗
PubMed1984

Effect of alcohol on plasma secretin concentration and pancreatic secretion in dogs.

We studied the effect of alcohol on plasma secretin concentration and pancreatic secretion in dogs with gastric cannulas and pancreatic fistulas. Intragastric administration of ethanol resulted in significant increases in pancreatic secretion of water and bicarbonate, which accompanied simultaneous increase in plasma secretin concentration. A more pronounced increase in pancreatic secretion occurred when ethanol was administered in the postprandial period. Integrated secretin release after a meal, 4.5 +/- 0.7 ng/ml-2 hr, had also increased significantly to 7.6 +/- 1.3 ng/ml-2 hr when ethanol was given in addition to a meal. Cimetidine pretreatment blocked the increase in plasma secretin concentration and pancreatic secretion in response to a meat meal and ethanol administration. This action of cimetidine paralleled its potent inhibitory effect on the exaggerated gastric acid secretion from Heidenhain pouches of dogs in response to ingestion of a meal and ethanol administration. Intraduodenal infusion of ethanol, however, failed to affect the plasma secretin concentration and pancreatic secretion. The present study indicates that alcohol stimulates release of endogenous secretin and pancreatic secretion by increasing duodenal acid load from the stomach stimulated by ethanol administration in dogs.

Animals↗
PubMed1984

Effect of 13-norleucin motilin on water and ion transport in the human jejunum.

Passage of the interdigestive migrating myoelectric complex through the proximal small bowel is associated with elevated plasma motilin levels and an increase in transmucosal potential difference suggesting altered ion transport. The aim of the present study was to investigate whether motilin may have an effect on intestinal water and ion transport. Steady state jejunal perfusion studies were carried out in healthy volunteers while either saline (control) or synthetic motilin (256 pmol/kg X h) was infused via peripheral vein. Plasma motilin levels rose from a mean of 31 to a plateau of 832 pmol/L. Motilin infusion significantly reduced absorption of water, sodium, potassium, and chloride when a plasmalike electrolyte solution was perfused. During perfusion with a bicarbonate-free salt solution, motilin significantly enhanced secretion of water, potassium, and chloride. Chloride secretion was active inasmuch as it occurred against both an electrical and chemical gradient. Motilin infusion had no effect on transit time during perfusion of the 30-cm jejunal test segments. We conclude that motilin can act as an intestinal secretagogue in the human jejunum.

Adolescent↗
PubMed1983

Radioimmunoassay of cholecystokinin.

A highly sensitive and specific radioimmunoassay for cholecystokinin (CCK) has been developed. Fully immunoreactive [125I]CCK33 was prepared by chloramine T-catalyzed iodination followed by purification by gel filtration and ion exchange chromatography. A high titer of antiserum was obtained by multiple immunizations of rabbits with 15% pure porcine CCK without conjugation. The antiserum was highly specific for CCK33 and CCK39, with 40% of the binding sites recognizing CCK8 at high affinity, but reacted weakly with gastrin. Plasma interference was eliminated by an XAD-2 resin column extraction technique with high recovery of CCK. The overall assay sensitivity was 3.3 pM with intra- and interassay coefficients of variation determined with a plasma of 11.2 pM at 9.6 and 20.8%, respectively. The assay was capable of detecting linear increments of both CCK33 and CCK8 added into plasma and intravenous infusion of CCK8 as low as 0.03 micrograms/kg/hr in dogs. The assay was validated by its ability to monitor increase of plasma CCK immunoreactivity after ingestion of a meat meal in both humans and dogs, as well as following intragastric infusion of liver extract meal and intraduodenal infusion of phenylalanine in dogs. When the CCK8 and gastrin binding sites of the antiserum were removed by immunoadsorption, the treated antiserum remained capable of measuring a postprandial change in plasma CCK concentration, indicating that CCK33-like immunoreactivity was present in the plasma.

Adsorption↗