Gut hormone profiles in critically ill neonates on extracorporeal membrane oxygenation

OBJECTIVES

The objective of this study was to gain insight into the hormonal responses to enteral nutrition in critically ill newborns requiring venoarterial extracorporeal membrane oxygenation (ECMO) by analyzing plasma gut hormone levels of gastrin, cholecystokinin and peptide-YY in relation to enteral nutrition.

METHODS

In 24 consecutive neonates treated with venoarterial ECMO intestinal hormone secretions were determined by radioimmunoassay at 2-day intervals. Twelve received parenteral nutrition only. In 12 enteral nutrition was introduced later. The findings in these patients were compared with those of 16 measurements in eight non-ECMO treated age-matched controls. Mixed model analysis of variance was used for statistical analysis.

RESULTS

Concentrations of gastrin, cholecystokinin and peptide-YY were significantly higher in ECMO patients receiving enteral nutrition compared with ECMO patients who received parenteral nutrition (62, 3.8 and 59.4 pmol/L versus 46, 3.1 and 34.7 pmol/L, respectively). Overall, plasma hormone levels did not differ from those in age-matched controls.

CONCLUSIONS

Intestinal hormone levels showed normal responses after introduction of enteral feeding, comparable with those in age-matched controls without ECMO. These results do not provide an argument for withholding enteral nutrition even in the most severely ill neonates on venoarterial ECMO.

Basal and fat-stimulated plasma peptide YY levels in celiac disease

The distal gut hormone peptide YY (PYY) mediates feedback inhibition of gastric acid secretion, gastrointestinal motility, and pancreatic enzyme output. To investigate the influence of maldigestion on PYY, we determined plasma PYY levels in patients with celiac disease under basal conditions and in response to intraduodenal fat. Basal PYY was increased in untreated celiac patients (N = 13) compared to patients on a gluten free diet (N = 9) [15.6 (11.8-27.0) pM vs 12.2 (10.1-13.1) pM; P < 0.05] and compared to control subjects (N = 15) [9.5 (8.3-10.4) pM; P < 0.001]. Integrated PYY in response to intraduodenally infused predigested fat (1071+/-293 pM 80 min) was significantly (P < 0.05) greater than in response to undigested fat (322+/-223 pM 80 min) in six untreated celiacs. Plasma concentrations of PYY and cholecystokinin were strongly correlated (r = 0.79; P < 0.001). We conclude that basal PYY levels in untreated celiac disease are elevated, that predigestion of fat enhances PYY release in these patients, and that PYY secretion is correlated with CCK release.

Effect of circulating peptide YY on gallbladder emptying in humans

BACKGROUND

To further establish its role in the ileal brake mechanism, we determined the effect of the distal gut hormone peptide YY (PYY) on gallbladder motility and plasma gut hormones during the cephalic phase of meal stimulation.

METHODS

Eight healthy volunteers were studied in a randomized crossover design, with or without intravenous infusion of a physiological dose of PYY. On each occasion, subjects underwent modified sham feeding followed by real feeding.

RESULTS

PYY reduced gallbladder emptying in response to modified sham feeding from 23 +/- 5% to 5 +/- 7% (P < 0.01) and integrated plasma pancreatic polypeptide from 2337 +/- 397 pmol/L x 90 min to 903 +/- 232 pmol/L x 90 min (P < 0.01). PYY enhanced plasma cholecystokinin in response to real feeding from 53 +/- 9 pmol/L x 90 min to 82 +/- 17 pmol/L x 90 min (P < 0.05), but did not significantly affect maximum gallbladder emptying and tended to decrease plasma pancreatic polypeptide.

CONCLUSION

Circulating PYY suppresses the cephalic phase of postprandial gallbladder emptying, but not meal stimulated maximum emptying. The results support the hypothesis that the effect of PYY on gallbladder emptying is mediated by vagal-dependent rather than cholecystokinin-dependent pathways.

Effect of subtotal colectomy on gastric emptying of a solid meal in slow-transit constipation

BACKGROUND

Idiopathic slow-transit constipation is considered a panenteral disease in which patients may have delayed gastric emptying. The effects of total abdominal colectomy and ileorectal anastomosis on upper gut motility are unknown. The aim of this study was to evaluate gastric emptying in patients with idiopathic slow-transit constipation before and after subtotal colectomy.

METHODS

Gastric emptying of a solid meal was studied by scintigraphic technique in 11 patients with idiopathic slow-transit constipation. The total colonic transit time was more than 72 hours in all patients studied, with delay in transit in all segments of the colon. The gastric emptying test was repeated 3 to 6 months after total abdominal colectomy and ileorectal anastomosis in ten of these patients. Before and after surgery, patients filled out a questionnaire to record upper gut symptoms.

RESULTS

Solid gastric emptying was delayed (T1/2 > upper limit of normal) in 7 of 11 patients with idiopathic slow-transit constipation. Gastric emptying T1/2 was almost similar before and after surgery. Mean +/- standard deviation was 142 +/- 91 minutes before surgery and 146 +/- 67 minutes after surgery. Symptoms of vomiting and belching improved significantly after surgery. Symptoms of nausea, bloating, and pyrosis also decreased, but these changes failed to reach statistical significance.

CONCLUSION

Despite a reduction in upper gut symptoms, total abdominal colectomy and ileorectal anastomosis does not improve delayed gastric emptying in patients with idiopathic slow-transit constipation.

Effects of Helicobacter pylori infection on endocrine and exocrine mucosal functions in the upper gastrointestinal tract

BACKGROUND

Helicobacter pylori infection affects the concentration of regulatory peptides such as gastrin, somatostatin and cholecystokinin and the concentration and activity of glutathione and glutathione S-transferases in the gastric mucosa.

METHODS

Literature review.

RESULTS

Although some of these peptides have been known since the beginning of this century, their action has changed since the discovery of H. pylori infection in 1983. Chronic infection with H. pylori might lead to an increased risk in developing gastric cancer. Glutathione S-transferases are involved in the cellular detoxification of xenobiotics and other toxic compounds. Since there is a close inverse relationship between the activity of glutathione S-transferase and incidence of malignancies in the gastrointestinal tract, the possible relation between H. pylori infection and activity of glutathione S-transferases in the gastric mucosa is discussed.

CONCLUSION

The effect of H. pylori infection on regulatory peptides and glutathione/glutathione S-transferases might play a role in the development of neoplastic changes of the H. pylori-infected gastric mucosa.

Plasma cholecystokinin, plasma peptide YY and gallbladder motility in patients with slow transit constipation: effect of intestinal stimulation

BACKGROUND/AIM

Because cholecystokinin and peptide YY are gut hormones with potent effects on gastrointestinal motility, we determined whether abnormalities of cholecystokinin and peptide YY exist in slow transit constipation.

METHODS

Plasma concentrations of these hormones before, during and after intraduodenal infusion of a liquid meal in 21 patients with slow transit constipation were compared with the results in 8 healthy controls.

RESULTS

Fasting levels of plasma cholecystokinin (3.1+/-0.2 vs. 2.4+/-0.2 pM; p = 0.02) were higher in patients. Basal plasma peptide YY (11.4+/-1.4 vs. 8.9+/-0.7 pM; p = 0.1) tended to be higher in patients. After the meal (60-90 min), incremental cholecystokinin (p<0.05), but not peptide YY, was significantly higher in patients. During intraduodenal infusion of the meal (0-60 min), incremental plasma cholecystokinin (251+/-20 pM.min) and peptide YY (1,146+/-186 pM. min) in patients were almost similar to control values (262+/-22 and 901+/-166 pM. min). Gallbladder volumes before, during and after the meal were not different between the 2 groups. Gastric emptying of a solid meal was delayed in the majority of patients (12 of 18). Abnormalities of plasma cholecystokinin were observed only in patients with delayed gastric emptying.

CONCLUSION

Plasma levels of cholecystokinin are elevated in the fasting state and decrease more slowly after stimulation, but maximum release in response to intestinal nutrients is not altered in patients with slow transit constipation. The abnormality seems to be confined to a subgroup of patients with delayed gastric emptying.

Effect of rectal distension on gallbladder emptying and circulating gut hormones

BACKGROUND

Abnormalities of upper gut motility, including a delay of gastric emptying and small bowel transit, found in patients with constipation may be secondary to factors originating in the colon or rectum as a result of faecal stasis. The aim was to determine if stimulation of mechanosensory function by rectal distension affects postprandial gallbladder emptying and release of gastrointestinal peptides participating in control of upper gut motility.

MATERIALS AND METHODS

Eight healthy volunteers were studied with an electronic barostat and a plastic bag positioned in the rectum. Intrabag pressure was maintained at minimal distension pressure + 2 mmHg on one occasion and on a pressure that induced a sensation of urge on the other. Gallbladder volume and plasma concentrations of cholecystokinin (CCK), pancreatic polypeptide (PP) and peptide YY (PYY) were measured before and after ingestion of a 450-kcal mixed liquid meal.

RESULTS

Rectal distension enhanced maximum gallbladder emptying from 66 +/- 7% to 78 +/- 5% (P < 0.05). Distension tended to increase integrated plasma PYY from 77 +/- 30 pM min to 128 +/- 40 pM min in the first hour after the meal (P = 0.08) and it suppressed integrated plasma PP from 1133 +/- 248 pM min to 269 +/- 284 pM min in the second hour (P < 0.05). Integrated plasma CCK concentrations were not significantly affected.

CONCLUSION

Mechanosensory stimulation of the rectum enhances postprandial gallbladder emptying and influences postprandial release of gut hormones involved in the regulation of gastrointestinal motility in healthy subjects. These mechanisms may play a role in the pathogenesis of the upper gastrointestinal motor abnormalities observed in constipated patients.

Sympathoadrenal activation and the dumping syndrome after gastric surgery

Dumping symptoms suggest concomitant sympathoadrenal activation. To evaluate the relation between dumping symptoms and postprandial plasma catecholamine changes, standardized dumping-provocation tests with use of oral glucose were performed for 16 gastric surgery patients with dumping, for 14 gastric surgery patients without dumping, and for 14 healthy control patients. Early dumping symptoms were present for all patients with dumping, and late symptoms developed in three patients with dumping after glucose ingestion. Patients without dumping and healthy control patients had slight complaints or no complaints. Systolic and diastolic blood pressure remained unaffected for the three groups. Positive breath-hydrogen tests, heart rate increments, and reactive plasma glucose decrements were present for patients with dumping and for patients without dumping, but not for control patients. Plasma noradrenaline and adrenaline increased for patients with dumping and for patients without dumping, but not for control patients. The noradrenaline increment was higher for patients with dumping (98%) than for patients without dumping (78%; p <0.05). The noradrenaline increment was related to the dumping score and to the heart rate increment for the first hour after glucose ingestion, whereas the adrenaline increment was related to the plasma glucose decrement for the third hour. Therefore, dumping symptoms clearly are accompanied by postprandial sympathoadrenal activation, but sympathoadrenal activation cannot account completely for development of dumping symptoms.

Role of circulating peptide YY in the inhibition of gastric acid secretion by dietary fat in humans

BACKGROUND

Intestinal fat inhibits gastric acid secretion and induces release of peptide YY (PYY) into the circulation. The aim of this study was to further establish the role of circulating PYY in the inhibition of gastric acid secretion by intraduodenal fat.

METHODS

Plasma PYY concentrations and gastrin-stimulated gastric acid output were measured in response to intravenous infusion of PYY in eight healthy men. The results were compared with those obtained after intraduodenal administration of dietary fat.

RESULTS

Plasma PYY concentrations increased by 8.1 +/- 1.8 pmol/l (P < 0.005) in response to the lower and by 13.5 +/- 2.5 pmol/l (P < 0.005) in response to the higher PYY dose. These increments were comparable to those observed after intraduodenal fat (10.3 +/- 2.4 pmol/l). Intraduodenal fat significantly inhibited (P < 0.005 versus control) gastrin-stimulated gastric acid secretion by 74% +/- 6%, but neither the lower (3% +/- 7%; NS) nor the higher PYY dose (1% +/- 10%; NS) induced any change in gastric acid output. PYY was biologically active, as reflected by a significant delay (P = 0.04) of orocaecal transit time.

CONCLUSION

Release of PYY into the circulation is not responsible for inhibition of gastrin-stimulated gastric acid secretion by dietary fat.

Abnormalities of upper gut motility in patients with slow-transit constipation

OBJECTIVE

To further delineate motor activity of the upper gastrointestinal tract in patients with slow-transit constipation.

DESIGN

A prospective study comparing healthy volunteers with patients with a clinical diagnosis of slow-transit constipation.

METHODS

Eighteen patients with clinical diagnosis of slow-transit constipation and 10 healthy controls were included in the study. Fasting antroduodenal motility was measured by perfusion manometry for at least one complete cycle of the migrating motor complex or a maximum of 300 min. Oesophageal manometry, gastric emptying and orocaecal transit time measurements were also performed.

RESULTS

At least one complete cycle of the migrating motor complex was observed in all controls, but in only nine patients (P < 0.01 versus control). The migrating motor complex cycle was incomplete (n = 5) or phase 3 activity was absent (n = 4) in the other patients. The incidence of clustered contractions was significantly increased in slow-transit constipation (P = 0.05 versus controls). The area under the contraction curve during late phase 2 (1509+/-296 mmHg x s) in patients with a complete cycle was significantly smaller than that in controls (2997+/-614 mmHg x s; P = 0.05). Orocaecal transit time was not significantly different among patients and controls, but oesophageal motility was abnormal in five of 18 patients and gastric emptying was abnormal in eight of 15 patients.

CONCLUSION

Abnormalities of upper gut motility occur frequently in patients with slow-transit constipation. Interdigestive antroduodenal motility is characterized by (i) absence or prolonged duration of the migrating motor complex, (ii) an increased number of clustered contractions, or (iii) a decreased motility during late phase 2 of the migrating motor complex.

Impaired release of peptide YY in patients with proctocolectomy and ileal pouch-anal anastomosis

BACKGROUND

Peptide YY (PYY) is a gut hormone produced by endocrine cells in the distal small bowel, colon, and rectum. PYY inhibits upper gastrointestinal secretory and motor functions. The aim of this study was to determine whether basal and postprandial plasma PYY levels in patients with proctocolectomy and ileal pouch-anal anastomosis (IPAA) are reduced and to determine the relationship between plasma PYY and plasma cholecystokinin (CCK) levels.

METHODS

Plasma concentrations of PYY and CCK were measured before and after ingestion of a standardized breakfast in 14 IPAA patients and in 12 healthy control subjects.

RESULTS

Basal PYY was slightly lower in the IPAA patients than in the controls (8.3 +/- 0.3 versus 9.3 +/- 1.1 pM; not significant). Ingestion of the meal induced a small but significant increase of PYY to a maximum of 10.9 +/- 0.9 pM in patients. Integrated postprandial PYY was markedly reduced in patients when compared with the controls (1725 +/- 66 pM*180min versus 3194 +/- 480 pM*180 min; P < 0.005). Plasma PYY concentrations were inversely correlated with plasma CCK concentrations in the 2nd and 3rd h after the meal (r = -0.86; P = 0.0001).

CONCLUSION

PYY release in response to meal ingestion is markedly reduced but not completely absent in patients with proctocolectomy and ileal pouch-anal anastomosis. The inverse relationship between circulating PYY and CCK in the late postprandial phase is compatible with a negative feedback regulation of CCK release by endogenous PYY.

The nondigestible fat sucrose polyester does not stimulate gallbladder emptying in humans

BACKGROUND

We determined the effect of oral ingestion of sucrose polyester, which was approved as a fat replacer in the United States, on gallbladder motility and on the release of cholecystokinin, the hormone that mediates gallbladder emptying.

OBJECTIVE

Our objective was to measure effects of sucrose polyester on gallbladder emptying and cholecystokinin release.

DESIGN

Eight healthy volunteers (3 men and 5 women) drank 60 mL sucrose polyester, digestible fat, or saline solution in a balanced crossover design on 3 separate days.

RESULTS

Mean (+/-SEM) gallbladder emptying, when integrated over time, was low in response to both sucrose polyester (-150 +/- 214 mL x 120 min) and saline solution (-89 +/- 123 mL x 120 min). In contrast, there was marked emptying in response to digestible fat (1069 +/- 253 mL x 120 min). Sucrose polyester did not affect plasma cholecystokinin concentrations (-9.3 +/- 15.0 pmol x 120 min/L), whereas digestible fat resulted in a significant increase (89.5 +/- 44.8 pmol x 120 min/L, P = 0.014) compared with saline solution (-3.0 +/- 13.8 pmol x 120 min/L).

CONCLUSIONS

Ingestion of sucrose polyester, in contrast with digestible fat, did not stimulate gallbladder emptying or release of cholecystokinin.

Effect of intraduodenal bile salt on pancreaticobiliary responses to bombesin and to cholecystokinin in humans

Bile salts modulate postprandial gallbladder emptying and pancreatic enzyme secretion, possibly by interfering with plasma cholecystokinin (CCK) responses. The regulatory role of bile salts in the absence of nutrients from the gut is poorly understood. Therefore, we studied the effect of intraduodenal sodium chenodeoxycholate on bombesin (BBS)- or CCK-stimulated plasma CCK levels, plasma pancreatic polypeptide levels, gallbladder motility, and pancreatic enzyme secretion. In a crossover design, saline without or with chenodeoxycholate was perfused intraduodenally for 3 hours in healthy volunteers. During the last hour, either BBS (n = 9) or CCK (n = 10) was infused intravenously. Chenodeoxycholate inhibited BBS-stimulated gallbladder emptying from 59% +/- 4% to 34% +/- 6% (P <.05) and intraduodenal bilirubin output from 41 +/- 9 to 21 +/- 5 micromol/h (P <.05), but it increased integrated plasma CCK levels from 157 +/- 19 to 184 +/- 19 pmol/L. 60 min (P =.01). Similarly, chenodeoxycholate administration inhibited gallbladder emptying and bilirubin output in response to intravenous CCK. Chenodeoxycholate also tended to reduce pancreatic polypeptide release and intraduodenal amylase output in response to intravenous BBS or CCK. It is concluded that intraduodenal chenodeoxycholate administration inhibits BBS- or CCK-stimulated gallbladder emptying, probably by diminishing target organ sensitivity to circulating CCK.

Plasma cholecystokinin and gallbladder responses to increasing doses of bombesin in celiac disease

Impaired postprandial gallbladder emptying in celiac disease has been attributed to an absence of appropriate cholecystokinin release. To determine if a flat jejunal mucosa in celiac patients is related to a reduced cholecystokinin-secreting capacity, increasing doses of bombesin were infused into six patients with celiac disease and a flat jejunal mucosa (group A), in seven celiac patients with a normal jejunal mucosa while on a gluten-free diet (group B), and in seven healthy controls (group C). Bombesin induced significant (P < 0.05) increments of plasma CCK to a maximum value of 1.0 +/- 0.3 pM in group A, to 1.5 +/- 0.3 pM in group B, and to 1.2 +/- 0.3 pM in group C (NS between groups), that were accompanied by significant (P < 0.05) gallbladder emptying responses of 70 +/- 4% in group A, 47 +/- 10% in group B and 65 +/- 5% in group C. Dose-response relationships were not different between groups. We conclude that there is no major impairment of gallbladder responsiveness to bombesin or of cholecystokinin-secreting capacity in patients with a flat jejunal mucosa due to celiac disease.

Release of peptide YY and inhibition of gastric acid secretion by long-chain and medium-chain triglycerides but not by sucrose polyester in men

METHODS

In the present study, we have investigated the effects of intraduodenal perfusion of long-chain and medium-chain triglycerides and of sucrose polyester on the release of peptide YY in healthy men.

RESULTS

Perfusion of medium-chain triglycerides (180 mmol fatty acids) increased the plasma concentration of peptide YY from 7.9 pmol L(-1) (SEM 0.2, n=8) to 10.7 pmol L(-1) (SEM 0.5, n=8), whereas perfusion of long-chain triglycerides (180 mmol fatty acids) had a significantly greater effect, increasing peptide YY concentration from 8 6 pmol L(-1) (SEM 0.2, n=8) to 18.9 pmol L(-1) (SEM 2.4, n=8, P < 0.008). A smaller quantity of long-chain triglycerides (90 mmol fatty acids) increased plasma concentration of peptide YY from 7.4 pmol L(-1) (SEM 0.4, n=8) to 13.3 pmol L(-1) (SEM 1.5, n=8), whereas sucrose polyester (90 mmol fatty acids) did not change peptide YY concentration. In a previous study, we investigated gastrin-stimulated gastric acid output in response to these treatments. The correlation between increases in peptide YY in response to all treatments and the decrease in acid output was r=0.72 (n=48, P < 0.0001). These results show that both long-chain and medium-chain triglycerides, but not sucrose polyester, stimulate the release of peptide YY.

CONCLUSION

We speculate that peptide YY may play an important role in the inhibition of gastrin-stimulated gastric acid secretion by long-chain and medium-chain triglycerides.

Inhibition of pancreaticobiliary secretion by loperamide in humans

Loperamide, a peripherally acting opiate receptor agonist with antidiarrheal action, inhibits ileal and colonic motor function. It was determined whether loperamide also affects gallbladder emptying and pancreatic enzyme secretion in humans. Plasma cholecystokinin (radioimmunoassay), gallbladder volume (ultrasonography), and intraduodenal bilirubin and amylase output (spot sampling) were measured at regular intervals before and during intraduodenal perfusion of an amino acid meal in 8 healthy subjects: once without and once with pretreatment of 8 mg loperamide, ingested 13 and 4 hours before the start of the meal. Loperamide decreased basal amylase output from 3.2 +/- 0.5 to 1.0 +/- 0.5 kU/h (P < .005) and abolished basal bilirubin output (21 +/- 5 vs. 0 +/- 0 micromol/h; P < .005) into the duodenum. Loperamide increased basal gallbladder volume from 28 +/- 4 to 39 +/- 4 mL (P < .0001) but was without effect on basal plasma cholecystokinin (2.7 +/- 0.3 vs. 3.0 +/- 0.3 pmol/L). During the amino acid meal, pretreatment with loperamide inhibited amylase output from 5.1 +/- 0.8 to 1.6 +/- 0.4 kU/h (P < .001), bilirubin output from 39 +/- 6 to 18 +/- 6 micromol/h (P < .0005) and gallbladder contraction from 47% +/- 3% to 26% +/- 6% (P < .05), whereas loperamide enhanced amino acid-stimulated plasma cholecystokinin from 4.5 +/- 1.6 to 7.6 +/- 1.0 pmol/L (P < .05). It is concluded that loperamide inhibits basal and amino acid-stimulated gallbladder motility and intraduodenal output of bilirubin and amylase, despite an enhanced postprandial cholecystokinin release.

Cholestyramine influences meal-stimulated pancreaticobiliary function and plasma cholecystokinin independent of gastric emptying and food digestion

BACKGROUND

Cholestyramine enhances gallbladder emptying and plasma cholecystokinin responses to oral ingestion of a mixed meal. It is not known whether this effect occurs independently of alterations in gastric emptying or maldigestion of nutrients.

METHODS

We perfused 15 g of an amino acid meal intraduodenally for 60 min in seven healthy volunteers, once with and once without cholestyramine. Intraduodenal perfusion of saline with or without cholestyramine (6 g/h) was started 60 min before the amino acid meal and continued for 2 h.

RESULTS

Cholestyramine markedly enhanced the incremental plasma cholecystokinin response to the meal from 36 +/- 12 to 139 +/- 25 pmol/l x 60 min (P < 0.005), incremental amylase output from 2.4 +/- 0.7 to 5.7 +/- 0.7 kU/h (P < 0.05), and incremental integrated gallbladder contraction from 1948 +/- 235 to 2840 +/- 189% x 60 min (P < 0.05).

CONCLUSION

The enhancing effect of cholestyramine on postprandial gallbladder contraction, pancreatic enzyme secretion, and plasma cholecystokinin release is not dependent on gastric emptying rates or appropriate digestion of nutrients.

Sucrose polyester does not inhibit gastric acid secretion or stimulate cholecystokinin release in men

Replacement of dietary fat by sucrose polyester reduces fat intake. However, little is known about the effects of sucrose polyester on gastrointestinal function. To investigate the effect on gastric acid secretion and on release of cholecystokinin into plasma, we perfused eight healthy male volunteers intraduodenally with sucrose polyester, digestible fat, or saline on separate days in random order. Intraduodenal perfusion of sucrose polyester did not suppress gastrin-stimulated gastric acid secretion (-1.8 +/- 6.8%) whereas digestible fat suppressed gastric acid secretion by 64 +/- 9% (P = 0.001) compared with saline. Sucrose polyester did not affect plasma cholecystokinin concentrations (-12.8 +/- 9.3 pmol.30 min/L) whereas perfusion with digestible fat resulted in a significant increase (31.7 +/- 9.3 pmol.30 min/L, P = 0.017) compared with saline. We conclude that sucrose polyester, in contrast with digestible fat, does not inhibit gastrin-stimulated gastric acid secretion or stimulate release of cholecystokinin.

Inhibition of gastrin-stimulated gastric acid secretion by medium-chain triglycerides and long-chain triglycerides in healthy young men

Long-chain triglycerides inhibit gastric acid secretion, but the effect of medium-chain triglycerides in humans is unknown. We compared the effects of intraduodenally perfused saline, medium-chain and long-chain triglycerides on gastrin-stimulated gastric acid secretion and cholecystokinin release. Eight healthy male volunteers participated in this study. Gastrin-stimulated gastric acid output was 9.4 +/- 1.1 mmol/30 min during saline perfusion. It was suppressed by medium-chain triglycerides by 43 +/- 9% (P = 0.04 vs. saline) and by long-chain triglycerides by 74 +/- 6% (P = 0.0003 vs. saline). Thus medium-chain triglycerides inhibited gastrin-stimulated gastric acid secretion but less so than long-chain triglycerides. When compared to saline perfusion (73 +/- 6 pM x 30 min) integrated plasma cholecystokinin concentrations were significantly elevated by long-chain triglycerides (96 +/- 5 pM x 30 min, P < 0.004) but not by medium-chain triglycerides perfusion (65 +/- 7 pM x 30 min). We also investigated the role of cholecystokinin infusion on gastrin stimulated gastric acid secretion. Higher concentrations (191.4 +/- 4.5 pM x 30 min) of CCK than released in the long-chain triglycerides perfusion experiment, did not suppress gastric acid secretion. Thus, circulating cholecystokinin appears not responsible for the inhibition of gastrin-stimulated gastric acid secretion by dietary fat.

Role of intraduodenal proteases in plasma cholecystokinin and pancreaticobiliary responses to protein and amino acids

BACKGROUND & AIMS

The role of small intestinal proteolytic activity in the regulation of upper gastrointestinal function in humans is poorly understood. The aim of this study was to determine the importance of proteolytic activity for protein- or amino acid-induced cholecystokinin release and pancreaticobiliary secretion.

METHODS

In 9 healthy subjects, saline was perfused intraduodenally for 3 hours either with or without the synthetic protease inhibitor camostate. During the last hour, albumin or amino acids in the same molecular composition as albumin were also perfused.

RESULTS

Perfusion with camostate, in concentrations that abolished intraduodenal proteolytic activity, had no effect on unstimulated plasma cholecystokinin concentrations or gallbladder emptying, but markedly (P < 0.05) increased unstimulated pancreatic enzyme output. Perfusion with protein distinctly stimulated cholecystokinin release, gallbladder emptying, and pancreatic enzyme output (P < 0.05). Perfusion with camostate resulted in significantly lower protein-stimulated plasma cholecystokinin, gallbladder, and pancreatic enzyme responses (P < 0.05). Perfusion with amino acids also stimulated plasma cholecystokinin, gallbladder emptying, and pancreatic enzyme output (P < 0.05). Camostate did not inhibit these values.

CONCLUSIONS

This study shows that appropriate digestion of protein is required to stimulate plasma cholecystokinin release, gallbladder emptying, and pancreatic enzyme secretion in humans.

Eradication of Helicobacter pylori infection in patients with non-ulcer dyspepsia. Effects on basal and bombesin-stimulated serum gastrin and gastric acid secretion

BACKGROUND

This study evaluates the effect of eradicating Helicobacter pylori on basal and bombesin-stimulated gastric acid secretion and serum gastrin in non-ulcer dyspepsia.

METHODS

Before and 1 month after an attempt to eradicate H. pylori basal and bombesin-stimulated gastric acid outputs were measured in 23 patients. H. pylori was eradicated in 15 patients (group A) but not in the other 8 (group B). Incremental gastric acid output was calculated by subtracting basal from bombesin-stimulated values.

RESULTS

Basal acid output increased significantly (p = 0.01) after therapy in group A (delta 1.6 +/- 0.6 mmol/h) but not in group B (delta 0.2 +/- 0.5 mmol/h). Incremental gastric acid output decreased distinctly (delta-3.9 +/- 1.4 mmol/h) after therapy in group A (p = 0.02) but not in group B (delta-2.2 +/- 1.7 mmol/h). Basal serum gastrin decreased significantly (p < 0.005) after therapy in group A (delta-9 +/- 4 pM) but not in group B (delta-1 +/- 2 pM). Integrated serum gastrin responses to bombesin decreased markedly (p < 0.001) after therapy in group A (delta-5.0 +/- 1.6 nM*60 min) but slightly in group B (delta-0.9 +/- 1.3 nM*60 min) (p < 0.05).

CONCLUSIONS

In patients with non-ulcer dyspepsia basal serum gastrin concentrations decrease but basal gastric acid outputs increase after eradication of H. pylori. Bombesin-induced increments in gastric acid output, however, decrease in parallel with gastrin release.

Plasma cholecystokinin levels and gallbladder volumes after proctocolectomy with ileal pouch-anal anastomosis

BACKGROUND

The colon and rectum contain regulatory peptides in mucosal endocrine cells, which suggests a hormonal role. In animal studies colectomy leads to increased plasma levels of cholecystokinin. Little is known about the effects of proctocolectomy with ileal pouch-anal anastomosis on the release of cholecystokinin in human beings. Therefore we studied the effects of this procedure on fasting, postprandial, and bombesin-stimulated plasma cholecystokinin levels and gallbladder volumes.

METHODS

Ten patients who had undergone proctocolectomy with ileal pouch-anal anastomosis and 12 healthy volunteers participated in the study. Fasting and postprandial plasma cholecystokinin levels and gallbladder volumes were studied for 3 hours at 15-minute intervals. In a second experiment plasma cholecystokinin levels were measured before and during intravenous administration of bombesin in six patients with ileal pouch and five healthy volunteers.

RESULTS

Fasting plasma cholecystokinin levels were higher (p < 0.05) in patients with ileal pouch-anal anastomosis (2.6 +/- 0.3 pmol/L) compared with controls (1.7 +/- 0.2 pmol/L). Integrated postprandial plasma cholecystokinin levels were also distinctly higher (p < 0.01) in patients (978 +/- 126 pmol/L.180 min) than in controls (588 +/- 60 pmol/L.180 min). Mean fasting gallbladder volume was significantly (p < 0.01) decreased in patients with ileal pouch-anal anastomosis (18 +/- 2 ml) compared with controls (28 +/- 2 ml). Postprandial gallbladder emptying as measured by percentage change was similar in both groups. After infusion of bombesin, integrated plasma cholecystokinin responses were higher (p < 0.05) in patients (161 +/- 20 pmol/L.20 min) than in controls (90 +/- 12 pmol/L.20 min).

CONCLUSIONS

Fasting, postprandial, and bombesin-stimulated plasma cholecystokinin levels are elevated in patients with ileal pouch-anal anastomosis compared with controls. Fasting gallbladder volume is decreased after ileal pouch-anal anastomosis. These findings suggest that the colon contains a factor that inhibits the release of cholecystokinin.

Improvement of gastric inflammation and resolution of epithelial damage one year after eradication of Helicobacter pylori

AIMS

To investigate the effect of eradication of Helicobacter pylori infection on gastric epithelial damage and gastritis, scored according to the Sydney system.

METHODS

Gastritis scores and epithelial damage were assessed in gastric biopsy specimens before, and five weeks and one year after anti-H pylori therapy in 66 patients with H pylori related gastritis.

RESULTS

The mean initial levels of activity, inflammation, atrophy, intestinal metaplasia, and H pylori scores were higher in the antrum than in the corpus or fundus. Eradication of H pylori resulted in an improvement in the mean inflammatory score in antral biopsy specimens from 2.23 before treatment to 1.32 and 1.06, respectively, five weeks and one year after treatment. Corresponding values for fundic biopsy specimens were 1.30, 0.36 and 0.35. Activity scores improved from 1.41 before treatment to 0.13 and zero, respectively, five weeks and one year after treatment in antral biopsy specimens and from 0.60 before treatment to zero in fundic biopsy specimens. Before treatment, epithelial damage was present in 51% of biopsy specimens taken from the antrum and 23% of those from the corpus. Five weeks after eradication of H pylori none of the biopsy specimens revealed evidence of epithelial damage.

CONCLUSION

Eradication of H pylori is followed by a rapid, significant improvement in the gastritis score and resolution of epithelial damage in antral and fundic mucosa.

Effect of predigested fat on intestinal stimulation of plasma cholecystokinin and gall bladder motility in coeliac disease

Cholecystokinin (CCK) release and gall bladder emptying in response to a fatty meal are completely abolished in coeliac disease. To determine the effect of lipid digestion on CCK release and gall bladder motility, six patients with untreated coeliac disease and a flat jejunal mucosa were studied on two separate days. After an overnight fast, the plasma CCK concentration and gall bladder volume were measured before and at regular intervals after the intraduodenal instillation of 60 ml corn oil (triglycerides) incubated with 40 ml saline or with 40 ml bile and pancreatic juice. The mean (SEM) concentration of free fatty acids in the aqueous phase of corn oil after incubation with bile and pancreatic juice (predigested corn oil) was 78 (35) mM compared with 0.1 (0.1) mM in the aqueous phase of corn oil incubated with saline (undigested corn oil). Integrated plasma CCK in response to predigested corn oil was significantly greater than that in response to undigested corn oil (101 (18) pM. 80 min v-2 (9) pM.80 min; p < 0.005). Similarly, integrated gall bladder contraction in response to predigested corn oil was significantly larger than that after undigested corn oil (817 (210) ml. 80 min v-225 (243) ml. 80 min; p < 0.05). In contrast to undigested corn oil, corn oil that has been predigested with bile and pancreatic juice induces plasma CCK secretion and gall bladder contraction in patients with untreated coeliac disease, presumably by generating and rendering soluble lipolytic products.

Effect of bile salt binding or protease inactivation on plasma cholecystokinin and gallbladder responses to bombesin

BACKGROUND/AIMS

Bombesin-stimulated plasma cholecystokinin levels decrease after an initial increase despite continuous infusion of bombesin. The aim of this study was to determine if a feedback mechanism, mediated by bile salts or proteolytic enzymes, is responsible for this decline.

METHODS

Bombesin (1.0 ng.kg-1.min-1) was infused into volunteers for 180 minutes on separate occasions. Cholestyramine, colestipol, camostate, or saline were perfused intraduodenally during the second hour of the tests. Cholestyramine was also administered without infusion of bombesin.

RESULTS

Colestipol and cholestyramine, dependent on their bile salt-binding capacity, markedly enhanced (P < 0.05) bombesin-stimulated plasma cholecystokinin from 2.1 +/- 0.5 pmol/L to 6.4 +/- 2.2 pmol/L and 12.1 +/- 3.3 pmol/L (P < 0.05 vs. colestipol), respectively, and further decreased gallbladder volume (P < 0.05) from 9.4 +/- 1.6 mL to 2.0 +/- 0.4 mL and 2.2 +/- 0.5 mL, respectively. The protease inhibitor camostate had no effect. Bile salt precipitation also enhanced plasma pancreatic polypeptide responses (P < 0.01) but did not alter gastrin responses. Plasma cholecystokinin responses to cholestyramine without bombesin infusion varied considerably, but increments were highly correlated to decreases in gallbladder volume (r = 0.91; P < 0.005).

CONCLUSIONS

Bile salt sequestration but not protease inactivation enhances plasma cholecystokinin and gallbladder responses to bombesin infusion in humans.

Loxiglumide inhibits cholecystokinin stimulated somatostatin secretion and simultaneously enhances gastric acid secretion in humans

In vitro studies have demonstrated that cholecystokinin releases somatostatin from the gastric mucosa. To date, there is no information about the in vivo significance of this finding in man. Therefore, we have studied the effect of infusion of cholecystokinin resulting in plasma concentrations within the range found after meal-stimulation, on somatostatin release and on gastric acid secretion. In addition we have studied these functions during infusion of the type A cholecystokinin receptor antagonist loxiglumide. In eight healthy subjects, basal gastric acid secretion was distinctly stimulated by cholecystokinin. The effect of cholecystokinin on gastric acid secretion was markedly enhanced by loxiglumide. Cholecystokinin also significantly stimulated somatostatin output into the gastric lumen, but not into the systemic circulation. Somatostatin output into the gastric lumen during infusion of cholecystokinin was abolished by loxiglumide. The data indicate that on the one hand circulating cholecystokinin, like gastrin, stimulates gastric acid secretion probably by binding to less specific type B receptors on parietal cells that are not blocked by loxiglumide, but on the other hand that cholecystokinin, in contrast to gastrin, also inhibits gastric acid secretion probably by binding to specific type A receptors present on somatostatin producing D-cells in the gastric mucosa, that are blocked by loxiglumide.

Basal serum gastrin concentrations before and after eradication of Helicobacter pylori infection measured by sequence specific radioimmunoassays

BACKGROUND

Helicobacter pylori infection of the antral mucosa is responsible for an increase in basal and stimulated serum gastrin. In the present study we have investigated whether gastritis induced by H. pylori is responsible for abnormalities in the processing of gastrin in dyspeptic patients.

METHODS

Basal serum gastrin was measured by radioimmunoassay before, 5 weeks, and 1 year after anti-H. pylori therapy in 73 H. pylori positive functional dyspeptic patients. Three region-specific antisera were used, specific for the biologically active carboxy-terminal part, the biologically inactive amino-terminal part of gastrin 1-17, and for the non-sulphated tyrosyl residue in gastrin 1-17.

RESULTS

Basal serum gastrin levels were markedly (P < 0.01) decreased 5 weeks and 1 year after successful eradication of H. pylori (n = 39) but not in the patients in whom treatment failed (n = 34). A decline of gastrin was observed for each of the three radioimmunoassays.

CONCLUSION

The decrease of serum gastrin levels in all three radioimmunoassays after a successful eradication of H. pylori does not point to major changes in the processing of gastrin. These results suggest that G-cells in the antral mucosa are not functionally affected by the inflammation.

Effect of erythromycin on pancreatic polypeptide release: role of the vagal nerve

To determine whether long vagal cholinergic pathways are involved in erythromycin-induced pancreatic polypeptide release, erythromycin was administered as an intravenous bolus injection to 9 healthy volunteers (group A) and to 13 patients (group B) with impaired vagal function as a result of truncal vagotomy or accidental vagotomy after antireflux surgery. In 7 of these patients (group B1) an antrectomy was also performed, while in the other 6 patients (group B2) the antrum was not removed. Pancreatic polypeptide was measured by radioimmunoassay at 5-min intervals twice before and at 2, 5, 10, 15, 30, 45 and 60 min after a 3.5 mg/kg bolus injection of erythromycin. On another day, a standard meal was administered and plasma pancreatic polypeptide was measured at 10-min intervals for 1 h. Erythromycin injection resulted in a lower integrated pancreatic polypeptide response in the patients of group B1 (247 +/- 89 pmol/l x 15 min; p = 0.005) and group B2 (497 +/- 111 pmol/l x 15 min; p = 0.05) when compared to the healthy subjects of group A (1,136 +/- 227 pmol/l x 15 min). The pancreatic polypeptide response to erythromycin in group B1 was reduced when compared to group B2, but the difference just failed to reach statistical significance (0.05 < p < 0.10). In the first 30 min after ingestion of a meal (cephalic phase) pancreatic polypeptide release was also markedly lower in group B1 (1,461 +/- 304 pmol/l x 30 min; p < 0.005) and group B2 (1,452 +/- 215 pmol/l x 30 min; p < 0.005) when compared to group A (3,541 +/- 452 pmol/l x 30 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Nutrient-specific effects of modified sham feeding on pancreatic polypeptide release

OBJECTIVE

To study the effect of meal composition on pancreatic polypeptide release during modified sham feeding.

DESIGN

In random order and on separate occasions, isocaloric, isothermic, isoosmotic, homogenized meals (1050 kJ; 250 kcal) either rich in fat (walnuts; 64 g fat, 7 g protein, 15 g starch per 100 g), protein (codfish, 1 g fat, 23 g protein per 100 g) or carbohydrates (bananas; 22 g starch, 1 g protein per 100 g) were sham-fed for 30 min by tasting and spitting out the meal. The plasma pancreatic polypeptide response was monitored by radioimmunoassay at 10 min intervals from 20 min before to 120 min after modified sham feeding.

SETTING

Department of Gastroenterology and Hepatology of a University Hospital.

SUBJECTS

Seven healthy volunteers: 3 male, 4 female; age 45 (range 30-77) years.

RESULTS

Integrated plasma pancreatic polypeptide responses to modified sham feeding of codfish (1088 +/- 395 pM*120 min; P < 0.05) and walnuts (1200 +/- 542 pM*120 min) were distinctly higher (P < 0.05) than to modified sham feeding of bananas (-390 +/- 291 pM*120 min).

CONCLUSIONS

These results demonstrate that the pancreatic polypeptide response to modified sham feeding is dependent on the composition of the meal.

Relation between gastric emptying of albumin-dextrose meals and cholecystokinin release in man

The effect of intragastric dextrose on albumin-stimulated cholecystokinin (CCK) release was studied in five healthy subjects and was related to gastric emptying and pancreatobiliary secretions. When combined with low concentrations of dextrose (4 g/100 ml), a 500-ml solution of albumin (7 g/100 ml) was rapidly emptied from the stomach into the duodenum (T1/2: 35 min). This rapid gastric emptying resulted in an only transient stimulation of pancreatobiliary secretion and an integrated CCK release of 278 +/- 45 pM x 180 min. When the concentration of dextrose in the albumin solution was increased from 4 g/100 ml to 21 g/100 ml, gastric emptying rate was distinctly slower (T1/2: 78 min; P < 0.01) and pancreatobiliary secretions became sustained (P < 0.01). CCK release was markedly higher (900 +/- 421 pM x 180 min; P < 0.05) after ingestion of the solution containing a high dextrose concentration. Intraduodenal infusion of 21 g/100 ml dextrose (3.1 ml/min) failed to significantly stimulate plasma CCK levels (119 +/- 38 pM x 120 min). We suggest that the higher CCK release in response to intragastrically administered albumin solution containing high concentrations of dextrose may have been induced by augmented peptic digestion of albumin due to delayed gastric emptying and by increased enteral digestion of albumin due to increased pancreatobiliary outputs.

Short report: smoking habits and the acquisition of metronidazole resistance in patients with Helicobacter pylori-related gastritis

Thirty-three dyspeptic patients with colonization of Helicobacter pylori in the gastric antrum were treated with tripotassium dicitrate bismuthate 120 mg q.d.s. for 28 days and metronidazole 250 mg q.d.s. for 10 days starting on day 19. Five weeks after cessation of this treatment regimen H. pylori was eradicated in 23 patients. In 8 of the remaining 10 patients, H. pylori had become resistant to metronidazole. In this study resistance was significantly associated with smoking habits, but not with age, bacterial load, gastritis score or alcohol consumption.

Gallbladder responses to modified sham feeding: effects of the composition of a meal

Changes in gallbladder contraction and plasma cholecystokinin release were studied following modified sham feeding of 3 different isocaloric meals rich in either fat, protein or carbohydrates in healthy volunteers, and results were compared with those following real feeding of comparable meals. In contrast to carbohydrate-rich meals (8 +/- 19 ml/120 min), fat- (-412 +/- 46 ml/120 min) and protein-rich meals (-352 +/- 42 ml/120 min) reduced integrated gallbladder volume (P < 0.05) in response to modified sham feeding. Plasma cholecystokinin levels were not significantly influenced by modified sham feeding of fat, protein or carbohydrates. Real feeding of a carbohydrate-rich meal also failed to significantly reduce gallbladder volume and to stimulate cholecystokinin release (-45 +/- 40 ml/120 min and 51 +/- 11 pmol/120 min, respectively), while real feeding of both fat- and protein-rich meals distinctly reduced gallbladder volume (-679 +/- 76 and -564 +/- 53 ml/120 min, respectively; P < 0.05) and increased cholecystokinin release (651 +/- 72 and 504 +/- 43 pmol/120 min, respectively; P < 0.05). This study demonstrates that gallbladder contraction during the cephalic phase of meal stimulation is dependent on the fat, protein and carbohydrate percentages of a meal, and is activated by different mechanisms than the intestinal phase of a meal.

Effect of ageing on postprandial conjugated and unconjugated serum bile acid levels in healthy subjects

Colorectal cancer is a disease of elderly subjects. A decreased ileal absorption of bile acids in elderly subjects may lead to an increased exposure of the colonic mucosa to secondary bile acids. This may contribute to an enhanced risk of colorectal cancer. In this study fasting and postprandial conjugated and unconjugated serum levels of cholic, chenodeoxycholic, and deoxycholic acid in 12 elderly and 12 younger subjects were investigated. Intestinal transit time, gallbladder emptying and jejunal bacterial flora were also studied in both age groups. Fasting levels of conjugated and unconjugated serum bile acids were similar in both age groups. Postprandial levels of all individual conjugated bile acids increased to a significantly higher extent in the younger subjects. Postprandial unconjugated serum bile acid levels did not differ significantly between both age groups, although unconjugated deoxycholic levels tended to increase to higher levels in the elderly. Results of jejunal bacterial counts, gallbladder emptying and intestinal transit time were similar in both groups. These data suggest that conjugated bile acids are reabsorbed less effectively in elderly subjects.

Postprandial gallbladder motility and plasma cholecystokinin at regular time intervals after injection of octreotide in acromegalics on long-term treatment

The increased risk of gallstone formation in acromegalics treated with the somatostatin analog octreotide has been related to an impaired gallbladder emptying. To determine the duration of these inhibitory effects, meal-stimulated gallbladder motility, plasma cholecystokinin (CCK), and pancreatic polypeptide (PP) were measured in five acromegalics treated for 6-32 months with 200-300 micrograms octreotide daily. Meal tests were performed 45 min, 8 hr and two weeks after the last 100-micrograms subcutaneous dose. Results were compared with those in normal subjects. Integrated postprandial gallbladder contraction (-125 +/- 194 cm3/120 min) and integrated PP secretion (-0.1 +/- 0.2 nmol/liter/120 min) were completely suppressed in the 45-min study, but significantly improved (P < 0.05) when measured 8 hr (1376 +/- 322 cm3/120 min and 3.0 +/- 1.0 nmol/liter/120 min) and two weeks (1437 +/- 263 cm3/120 min and 10.6 +/- 1.6 nmol/liter/120 min) after the last dose of octreotide. The integrated gallbladder contraction in acromegalics at 8 hr was comparable to that at two weeks and to that in normal subjects, but the integrated PP response at 8 hr was significantly smaller (P < 0.05 vs two weeks and vs normals). Integrated plasma CCK secretion at 45 min (0.13 +/- 0.06 nmol/liter/120 min) was not statistically significantly different from the response at 8 hr (0.15 +/- 0.02 nmol/liter/120 min) and from that in normal subjects, but it was significantly increased at two weeks after cessation of octreotide (P < 0.05 vs 45 min and 8 hr).(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreatic morphology and function in adult patients with cystic fibrosis

To determine the relation between pancreatic morphology and pancreatic exocrine and endocrine function, we have studied 8 adult cystic fibrosis patients and 14 normal control subjects by ultrasonography and pancreatic function testing. In the patients with cystic fibrosis the maximum anteroposterior diameter of the pancreatic head was significantly increased over that in control subjects (p less than 0.01), whereas the maximum diameter of the body was significantly decreased (p = 0.05). Increased echogenicity of the pancreatic body was observed in most patients. In the cystic fibrosis patients postprandial insulin secretion was reduced in the 1st h (p less than 0.005 versus control), whereas pancreatic polypeptide secretion was virtually abolished for at least 3 h (p less than 0.01 versus control). All cystic fibrosis patients had evidence of exocrine pancreatic dysfunction as reflected by a diminished urinary para-aminobenzoic acid excretion. Intraduodenal enzyme and bicarbonate output in response to secretin-cholecystokinin was reduced in all of three patients studied. It is concluded that loss of endocrine and exocrine pancreatic function in adult cystic fibrosis patients is accompanied by a small and echo-dense pancreatic body relative to a large pancreatic head.

Fasting gallbladder volume, postprandial emptying and cholecystokinin release in gallstone patients and normal subjects

Since abnormal gallbladder emptying may be a contributing factor in the development of gallstone disease, we determined fasting gallbladder volume and postprandial contraction in 20 gallstone patients and 20 normal subjects with the aid of ultrasonography. Moreover, basal plasma cholecystokinin levels and postprandial cholecystokinin (CCK) release were determined. Gallstone patients were divided into strong contractors (13 pts) and weak contractors (below 95% confidence interval for AUC contraction in % during 90 min: 7 pts). Strong contractor patients had significantly larger mean fasting volumes than normal subjects (mean +/- S.E.: 34.9 +/- 6.1 ml and 18.9 +/- 1.6 ml, respectively). This was not true for weak contractor patients (mean fasting volume 23.2 +/- 3.2 ml). Both strong contractor and weak contractor patients had significantly higher mean residual volumes than normal subjects (17.0 +/- 4.1 ml, 18.0 +/- 2.9 ml, and 8.8 +/- 1.1 ml, respectively). Absolute gallbladder emptying was significantly higher for strong contractor patients than for normal subjects, but relative emptying was the same. Opposite patterns of CCK release occurred in gallstone patients and normal subjects. In normal subjects, more CCK release was associated with stronger gallbladder emptying. In contrast, weak contractor gallstone patients had significantly higher CCK release than strong contractor patients. (AUC CCK: 304 +/- 89 pmol/l x 90 min and 106 +/- 29 pmol/l x 90 min, respectively). The present study indicates that strong contractor gallstone patients may have large residual gallbladder volumes due to large starting volumes, whereas weak contractor patients may have large residual volumes due to impaired contraction. Subjects with large fasting and residual volumes may be at increased risk for gallstone disease.(ABSTRACT TRUNCATED AT 250 WORDS)

A decade of experiences with radioimmunoassays for cholecystokinin in The Netherlands

The radioimmunologic determination of cholecystokinin (CCK) has proved to be notoriously difficult. This is due to the specificity of antibodies, preparation of radiolabeled CCK and low CCK concentrations in human plasma. About 10 years ago we succeeded in developing two highly sensitive region-specific radioimmunoassays for CCK. Antibody T204 binds to the sulfated tyrosine region of CCK, while antibody 1703 reacts with biologically active molecular forms of CCK containing at least 14 amino acid residues. Both antibodies are devoid of significant cross-reaction with gastrin. By means of these two radio-immunoassays CCK concentrations were measured in both tissue and plasma of various species, including man. In addition, the molecular forms of CCK in tissue and plasma were characterized. These CCK assays were used to study the mechanism of CCK secretion. It appeared that digested rather than intact protein and fat stimulated CCK release from the small intestine. The physiologic and pathophysiologic role of CCK in humans was studied using CCK radioimmunoassays and specific CCK-receptor antagonists. CCK was found to play an important role in pancreatic enzyme secretion, gallbladder contraction, and gastrointestinal motility but possibly also in pancreatic carcinogenesis and regulation of satiety and satiation.

Omeprazole. A pharmaco-epidemiological study of its use in a university hospital

A pharmaco-epidemiologic study in hospitalized patients was carried out in order to establish the place and use of omeprazole (Losec), a new and promising drug in the treatment of acid-related diseases. A comparison is made with cimetidine and ranitidine use. It appeared that prescribed omeprazole doses were high in relation to the established defined daily doses and that substitution of H2 receptor antagonists by omeprazole led to tremendously increased drug costs. From the clinical indication data it could be established that the drug was prescribed appropriately.

Increased plasma cholecystokinin levels and small gall bladders in adult patients with cystic fibrosis

1. In patients with cystic fibrosis, abnormalities in plasma cholecystokinin level and gall-bladder emptying may contribute to the development of maldigestion and gall-stones. 2. Therefore, we have measured plasma cholecystokinin levels and gall-bladder volumes before and after ingestion of a standard breakfast in eight adult patients with cystic fibrosis and in eight normal control subjects. 3. In the patients with cystic fibrosis basal (2.8 +/- 0.4 pmol/l; P less than 0.05, t-test) and maximum post-prandial (5.7 +/- 0.5 pmol/l; P less than 0.05, t-test) plasma cholecystokinin levels were significantly higher than those in the control subjects (1.9 +/- 0.1 pmol/l, and 4.5 +/- 0.2 pmol/l, respectively). On the other hand, integrated plasma cholecystokinin secretion in response to the meal was similar (t-test, P = 0.4 versus control subjects). The increased plasma cholecystokinin levels in the patients with cystic fibrosis were accompanied by reduced gallbladder volumes in both the basal (7.8 +/- 2.1 cm3 versus 20.9 +/- 2.3 cm3 in control subjects; P less than 0.005, t-test) and the post-prandial state (2.2 +/- 1.0 cm3 versus 4.8 +/- 0.8 cm3 in control subjects; P = 0.06, t-test). Gall-bladder emptying in the patients with cystic fibrosis was well preserved (70 +/- 7% versus 78 +/- 9% in control subjects; P = 0.4, t-test). 4. In comparison with normal control subjects, patients with cystic fibrosis have an increased basal plasma cholecystokinin level and a reduced gall-bladder volume, whereas post-prandial gall-bladder emptying and plasma cholecystokinin secretion are not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Severely impaired postprandial gallbladder emptying despite unchanged cholecystokinin release in the early phase of biliary colic

In the present article we report transitory severely impaired postprandial gallbladder emptying preceding biliary colic in a cholesterol gallstone patient. Gallbladder emptying 1 wk before and 3 wk after the biliary colic was normal. Treatment with ursodeoxycholic acid led to increased fasting gallbladder volumes, but the postprandial residual volume did not change. Postprandial cholecystokinin release appeared not to change during ursodeoxycholic acid treatment or during biliary colic.

Gallbladder volume and contraction measured by sum-of-cylinders method compared with ellipsoid and area-length methods

Gallbladder volume, determined by ultrasonography (US) using the sum-of-cylinders (SOC) method, is tedious and time-consuming. We therefore examined whether ellipsoid (ELL) or area-length (A-L) methods, which are easier to perform, could reliably replace the SOC method. Fasting gallbladder volume and emptying were determined according to these 3 methods in 20 normal subjects and 20 gallstone patients. Excellent correlations were found but the ELL method yielded significantly larger mean volumes and the A-L method revealed significantly smaller volumes than the SOC method. Analysis of differences between methods revealed a considerable lack of consistency. Volumes according to the ELL method were 35 percent larger to 46 percent smaller for normal subjects and 34 percent larger to 41 percent smaller for gallstone patients than volumes according to the SOC method. Volumes according to the A-L method were 35 percent larger to 15 percent smaller for normal subjects and 51 percent larger to 17 percent smaller for gallstone patients. Maximal decrement of gallbladder volume in ml and in percentage according to the 3 different methods did not differ. Regardless of the method used, both fasting and minimal gallbladder volumes were significantly larger in gallstone patients than in normal subjects, whereas maximal decrement of gallbladder volume in ml and percentage was not different. The present study indicates that the SOC method remains the method of choice for US determination of gallbladder volume for scientific purposes.

Effects of ursodeoxycholic acid on gallbladder contraction and cholecystokinin release in gallstone patients and normal subjects

It has been previously suggested that treatment with ursodeoxycholic acid leads to decreased gallbladder emptying. The proposed mechanism is decreased release of cholecystokinin through negative feedback control by an increased amount of intraduodenal bile acids. In the present study we examined cholecystokinin release and gallbladder contraction after oral administration of a commercial fatty meal (Sorbitract; Dagra, Diemen, The Netherlands) using ultrasonography in eight normal subjects and eight gallstone patients before and after 1 and 4 weeks of treatment with ursodeoxycholic acid (10 mg kg-1.day-1). Fasting gallbladder volume increased in 15 of 16 subjects during treatment (P less than 0.01). Minimal volume did not change. Therefore, both absolute and relative gallbladder emptying increased during therapy. Maximal decrement of gallbladder volume in milliliters and percentage as well as integrated gallbladder contraction during 90 minutes in milliliters and percentage were significantly increased after 1 and 4 weeks of treatment with ursodeoxycholic acid when compared with data before therapy. Gallstone patients tended to have larger fasting and residual gallbladder volumes than normal subjects, whereas parameters for the amount of bile expelled (maximal decrement of gallbladder volume and integrated gallbladder contraction in milliliters and percentage) did not differ. Release of cholecystokinin did not change during treatment and did not differ significantly between patients and normal subjects. Mean relative percentage of ursodeoxycholic acid in bile during treatment in 13 subjects consenting to have duodenal intubation was 47% (range 31%-60%). Changes of fasting gallbladder volume after institution of bile acid treatment correlated significantly (r = 0.74, P less than 0.01) with changes of cholesterol saturation index but not with relative percentage of ursodeoxycholic acid in bile. This study indicates that gallbladder emptying does not decrease during treatment with ursodeoxycholic acid. Moreover, there is no evidence of decreased cholecystokinin release.

Effect of partial gastrectomy with Billroth II or Roux-en-Y anastomosis on postprandial and cholecystokinin-stimulated gallbladder contraction and secretion of cholecystokinin and pancreatic polypeptide

This prospective study was undertaken to determine the effect of partial gastrectomy without vagotomy on postprandial gallbladder contraction and secretion of cholecystokinin (CCK) and pancreatic polypeptide (PP) in 22 peptic ulcer patients randomly assigned to either Billroth II (N = 11) or Roux-en-Y (N = 11) anastomosis. The patients were studied within two weeks before surgery and at six months postoperatively. After surgery basal gallbladder volumes were larger than preoperatively (P less than 0.02). Integrated postprandial gallbladder contraction was not significantly affected by gastrectomy, either in the patients with Billroth II anastomosis (2276 +/- 268 vs 1985 +/- 362%/60 min) or in those with Roux-en-Y anastomosis (2045 +/- 327 vs 2445 +/- 352%/60 min) when studied pre- and postoperatively, respectively. Similarly, integrated postprandial plasma CCK secretion was not significantly changed by either Billroth II gastrectomy (200 +/- 31 vs 166 +/- 21 pM/60 min) or Roux-en-Y gastrectomy (146 +/- 26 vs 147 +/- 12 pM/60 min). However, integrated postprandial PP secretion was significantly (P less than 0.05) lower after Billroth II gastrectomy (6.8 +/- 2.4 vs 2.2 +/- 1.0 nM/60 min), while the reduction in plasma PP after Roux-en-Y gastrectomy just failed to reach statistical significance (6.0 +/- 1.5 vs 3.4 +/- 0.9 nM/60 min). Similarly, the PP response, but not the gallbladder response, to an intravenous bolus injection of 1 IDU CCK/kg body weight was significantly decreased after gastrectomy independent of the type of anastomosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Postprandial exocrine pancreatic function during long-term treatment with the somatostatin analogue SMS 201-995 in acromegalic patients

Long-term treatment with the somatostatin analogue SMS 201-995 (SMS) might impair exocrine pancreatic function, secretion of cholecystokinin (CCK) and pancreatic polypeptide (PP), and pancreatic size. In five acromegalics on chronic treatment with SMS, we investigated postprandial 6-h urinary excretion of p-aminobenzoic acid (PABA) and p-aminosalicylic acid (PAS) after s.c. injection of 100 micrograms SMS or placebo and after ingestion of 2 mmol nBT-PABA and 2 mmol PAS. In the acromegalics, urinary PABA/PAS ratio (reflecting exocrine pancreatic function) after SMS was similar to that after placebo (P greater than 0.10) and higher than in healthy volunteers (n = 8, P = 0.05). The initial inhibition of plasma CCK secretion by SMS was cancelled during the 3rd h after the meal, whereas PP release remained completely abolished. Pancreatic size as measured by ultrasonography, was not reduced in seven acromegalics compared with 14 healthy volunteers. It is concluded that despite a blunted release of the trophic hormone CCK, long-term treatment with SMS 201-995 neither induces an abnormally small pancreas nor deterioration of postprandial exocrine pancreatic function in patients with acromegaly.

Role of cholecystokinin and the cholinergic system in intestinal stimulation of gallbladder contraction in man

To determine the role of cholecystokinin and the cholinergic system in intestinal stimulation of gallbladder contraction, we studied the effects of atropine on plasma cholecystokinin and gallbladder contraction in six healthy volunteers (four men and two women aged 20 to 27 yr). Effects were noted after intraduodenal fat instillation and after dosage with exogenous cholecystokinin inducing plasma cholecystokinin concentrations similar to those after intraduodenal fat instillation. At regular intervals before and after administration of each stimulus, plasma cholecystokinin concentrations and gallbladder volumes were measured by radioimmunoassay and real-time ultrasonography, respectively. Intraduodenal infusion of 250 ml 20% Intralipid induced a peak plasma cholecystokinin increment of 10.2 +/- 1.6 pmol/L compared with 10.7 +/- 0.7 pmol/L during infusion of 1 Ivy dog unit per kilogram per hour of cholecystokinin. The increases in plasma cholecystokinin after fat and exogenous cholecystokinin administration were accompanied by similar decreases in gallbladder volume. Integrated gallbladder contraction after fat instillation was 3,939% +/- 288%.min compared with 3,301% +/- 359%.min during cholecystokinin infusion (NS). Atropine (0.015 mg/kg as bolus followed by 0.005 mg/kg/hr) did not change plasma cholecystokinin concentrations but induced similar inhibition of gallbladder contraction to 2,296% +/- 511%.min (p less than 0.05) after intraduodenal fat instillation and to 1,756% +/- 456%.min (p less than 0.05) during cholecystokinin infusion. We conclude that cholecystokinin is of major importance in intestinal stimulation of gallbladder contraction. Atropine inhibits the gallbladder response to intraduodenal fat. This inhibition is not due to a reduction in cholecystokinin secretion but to a diminished gallbladder response to cholecystokinin.

Effect of increasing oral doses of loperamide on gallbladder motility in man

1. Loperamide, a peripherally acting opiate receptor agonist with antidiarrhoeal action, inhibits ileal and colonic motor function. To determine the effect of loperamide on gallbladder motility, we have pretreated five healthy volunteers with 2 mg oral loperamide 24 h, 20, 12 and 2.5 h before; six healthy volunteers with 16 mg oral loperamide 2.5 h before; and eight healthy volunteers with 16 mg oral loperamide 12 and 2.5 h before intravenous infusion of a 'physiological dose' of 12.5 pmol kg-1 cholecystokinin (CCK) for 1 h to stimulate gallbladder contraction. All subjects served as their own controls. Gallbladder volume was measured by ultrasonography and plasma CCK by radioimmunoassay until 90 min after start of the CCK infusion. 2. Infusion of CCK resulted in plasma CCK concentrations similar to those after intraduodenal fat. Integrated gallbladder contraction after 4 X 2 mg loperamide (4600 +/- 891% min) was similar to that without pretreatment (5270 +/- 1037% min; NS). Integrated gallbladder contraction after 1 X 16 mg loperamide diminished from 5458 +/- 412% min without to 2632 +/- 816% min with loperamide (P less than 0.05), and was completely abolished to -596 +/- 762% min (P less than 0.0005 vs without loperamide) after 2 X 16 mg loperamide. 3. It is concluded that loperamide inhibits gallbladder contraction in response to a physiological dose of cholecystokinin in a dose-dependent manner.

Pancreatic exocrine and gallbladder function during long-term treatment with octreotide (SMS 201-995)

Since octreotide (SMS 201-995, Sandostatin; Sandoz Pharmaceuticals) is a potent inhibitor of pancreatic exocrine secretion and gallbladder contraction, long-term treatment with this drug may theoretically result in impaired pancreatic function and gallstones. However, we observed excellent pancreatic exocrine function--as assessed by the PABA/PAS test--in acromegalics who received octreotide treatment for more than 6 months. Plasma cholecystokinin showed a significant, although blunted, postprandial response, which exceeded the threshold for gallbladder contraction in healthy controls. Remarkably, postprandial gallbladder contraction was completely abolished for at least 2 h during octreotide treatment. In contrast to other studies, none of 16 acromegalic patients on long-term octreotide treatment developed gallstones. Although the incidence of gallstones in patients on long-term octreotide treatment may be increased, the risk seems to be variable.

Simultaneous measurement of gallbladder emptying with cholescintigraphy and US during infusion of physiologic doses of cholecystokinin: a comparison

Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying.

Postprandial gallbladder motility during long term treatment with the long-acting somatostatin analog SMS 201-995 in acromegaly

The effects on gallbladder motility of long term treatment with the somatostatin analog SMS 201-995 (SMS) were studied in five patients with acromegaly treated for 6-32 months with 200-300 micrograms SMS daily. SMS (100 micrograms) or placebo was injected sc 45 min before a standard breakfast. Gallbladder volume (ultrasonography), plasma cholecystokinin (CCK), and pancreatic polypeptide (PP) were measured until 120 min after the meal. SMS completely suppressed the postprandial gallbladder contraction, despite a blunted, though still statistically significant, increase in plasma CCK from 1.6 +/- 0.2 pmol/L to an average of 3.7 +/- 1.7 pmol/L (P less than 0.01). The postprandial plasma PP peak after placebo was replaced by a slight but statistically significant decrease after SMS (P less than 0.05). A statistically significant correlation between the plasma CCK values and corresponding gallbladder volumes was seen only after placebo injection, not in the SMS study. We conclude that during long term treatment of acromegalics with SMS, an injection of 100 micrograms, sc, completely abolishes gallbladder contraction for at least 2 h after a standard breakfast, despite blunted, but still significant, CCK release. The data suggest a decreased sensitivity of the gallbladder to endogenous CCK during long term treatment with SMS. Careful control of patients with respect to the formation of gallstones is recommended.