H. A. J. Gielkens

Effect of insulin on basal and cholecystokinin-stimulated gallbladder motility in humans

BACKGROUND/AIMS Acute hyperglycemia inhibits gallbladder contraction. In non-diabetic subjects this inhibitory effect may result from endogenous hyperinsulinemia. Therefore we investigated the effects of acute hyperglycemia and euglycemic hyperinsulinemia on basal and cholecystokinin-stimulated gallbladder motility. METHODS Gallbladder volume (ultrasonography) and duodenal bilirubin output were studied simultaneously in nine healthy volunteers (age 20-52 years) on 3 separate occasions in random order during: (a) saline infusion (control), (b) hyperglycemic hyperinsulinemic clamping (HG; plasma glucose at 15 mmol/l), and (c) euglycemic hyperinsulinemic clamping (HI; plasma insulin at 150 mU/l, glucose at 4-5 mmol/l). After a 2-h basal clamp period, cholecystokinin was infused intravenously for 60 min at 0.25 IDU x kg(-1) x h(-1), followed by another 60 min at 0.5 IDU x kg(-1) x h(-1). RESULTS HI and HG significantly (p<0.05) reduced basal duodenal bilirubin output compared to control, while basal gallbladder volume did not change. At the low dose cholecystokinin, gallbladder emptying during HG (25+/-3%) and HI (39+/-4%) was significantly (p<0.01) reduced compared to control (61+/-4%). The inhibitory effect of HG was significantly (p<0.05) stronger compared to HI. Duodenal bilirubin output during the low dose cholecystokinin was significantly (p<0.05) reduced by HG, but not by HI. No inhibitory effect of HG and HI on gallbladder emptying and duodenal bilirubin output was observed with the high dose of cholecystokinin. CONCLUSIONS In healthy subjects acute hyperglycemia and euglycemic hyperinsulinemia reduce basal duodenal bilirubin output and inhibit gallbladder emptying stimulated by low dose cholecystokinin. These results suggest that insulin is involved in the inhibitory effect of hyperglycemia on basal and cholecystokinin-stimulated gallbladder motility.

Effect of gastrin on antroduodenal motility: role of intraluminal acidity

The effect of gastrin on the migrating motility complex (MMC) was studied in seven healthy subjects. It was hypothesized that a potential effect of gastrin on the MMC may result from intraluminal acidification through increased gastric acid secretion. Therefore, antroduodenal manometry and intraluminal acidity were recorded simultaneously. The effect of gastric acid inhibition, with and without administration of gastrin, on antroduodenal motility and intraluminal acidity was also evaluated and compared with saline infusion (control). Continuous infusion of gastrin-17 (20 pmol ⋅ kg-1 ⋅ h-1) increased intragastric and intraduodenal acidity and suppressed phase II and phase III motor activity in both antrum and duodenum. Concomitant gastric acid inhibition with intravenous famotidine, as demonstrated by intragastric neutralization of pH, completely antagonized the effect of gastrin on the MMC. In fact, famotidine infusion, both with and without administration of gastrin, significantly shortened MMC cycle length. It is concluded that the effect of gastrin on interdigestive antroduodenal motility results from increased intraluminal acidity.The effect of gastrin on the migrating motility complex (MMC) was studied in seven healthy subjects. It was hypothesized that a potential effect of gastrin on the MMC may result from intraluminal acidification through increased gastric acid secretion. Therefore, antroduodenal manometry and intraluminal acidity were recorded simultaneously. The effect of gastric acid inhibition, with and without administration of gastrin, on antroduodenal motility and intraluminal acidity was also evaluated and compared with saline infusion (control). Continuous infusion of gastrin-17 (20 pmol. kg-1. h-1) increased intragastric and intraduodenal acidity and suppressed phase II and phase III motor activity in both antrum and duodenum. Concomitant gastric acid inhibition with intravenous famotidine, as demonstrated by intragastric neutralization of pH, completely antagonized the effect of gastrin on the MMC. In fact, famotidine infusion, both with and without administration of gastrin, significantly shortened MMC cycle length. It is concluded that the effect of gastrin on interdigestive antroduodenal motility results from increased intraluminal acidity.

Post-prandial intragastric and duodenal acidity are increased in patients with chronic pancreatitis

: Patients with chronic pancreatitis and exocrine insufficiency have lower intraduodenal pH compared to controls. It has been assumed that abnormal low intraduodenal pH in these patients not only results from impaired pancreatic bicarbonate secretion but also from an increased gastric acid load to the duodenum.

Effects of Parenteral Nutrients on Gastrointestinal Motility and Secretion

BACKGROUND The stimulation of gastrointestinal motility and secretion during nutrient digestion is generally divided into a cephalic, gastric and intestinal phase. Little is known about the effects of macronutrients on gastrointestinal function during the postabsorptive or circulatory phase of digestion. METHODS Review of studies investigating the effects of circulating macro-nutrients such as fat, amino acids and glucose on gastrointestinal motility and secretion. RESULTS Intravenous infusion of fat emulsions delays gastric emptying and interrupts the interdigestive intestinal motor pattern. Intravenous amino acids, administered in high doses, stimulate gastric acid secretion, pancreatic secretion, gallbladder contraction, and intestinal motility. Patients receiving total parental nutrition (TPN) have inert gallbladders and are at risk of developing gallbladder sludge and stones. Administering a proportion of the daily amino acid requirement by rapid intravenous infusion may prove useful in the prevention of sludge and stone formation during TPN by promoting gallbladder contraction. Intravenous infusion of glucose, already at physiological postprandial plasma levels, inhibits gastrointestinal motility and secretion. The inhibitory effect of glucose is dose-dependent, that is, more pronounced at higher plasma glucose levels. Recent studies have indicated that in patients with diabetes mellitus alterations in gastrointestinal function are related to the degree of hyperglycaemia. CONCLUSIONS Nutrients during the circulatory phase of digestion influence gastrointestinal motility and secretion. Knowledge of these effects is relevant for conditions with increased plasma levels of macro-nutrients such as in patients with diabetes mellitus or during total parenteral nutrition.

Gallbladder motility and cholecystokinin secretion in chronic pancreatitis: relationship with exocrine pancreatic function

BACKGROUND/AIMS Postprandial gallbladder motility is regulated mainly by the hormone cholecystokinin (CCK). Since CCK secretion may be reduced in patients with pancreatic insufficiency (PI), we studied postprandial gallbladder motility in these patients. METHODS Fifteen patients with PI due to chronic pancreatitis and 17 healthy control subjects were studied. Gallbladder volumes (ultrasonography) and plasma CCK concentrations (RIA) were determined at regular intervals for 120 min after meal ingestion. Urinary PABA and faecal fat excretion were measured to determine pancreatic exocrine function. RESULTS Patients with PI had larger fasting gallbladder volumes than controls (48 +/- 6 cm3 versus 29 +/- 2 cm3; p < 0.01). Gallbladder ejection volume at time 120 min was not significantly different between patients with PI (14 +/- 4 cm3) and controls (20 +/- 2 cm3). However, the percentage postprandial gallbladder emptying in patients with PI was significantly reduced compared to controls (at 120 min: 29 +/- 8% versus 68 +/- 3%; p < 0.001). Residual postprandial gallbladder volume was increased in patients with PI compared to controls (at 120 min: 34 +/- 4 cm3 versus 9 +/- 1 cm3; p < 0.001). Postprandial endogenous CCK secretion was significantly reduced in patients with PI compared to controls (78 +/- 13 pM.120 min versus 155 +/- 14 pM.120 min; p < 0.001). Postprandial gallbladder emptying (%) was related to the degree of exocrine pancreatic insufficiency (r = 0.81; p < 0.001). CONCLUSIONS In patients with pancreatic insufficiency due to chronic pancreatitis: 1) fasting and residual postprandial gallbladder volumes are significantly increased; 2) postprandial CCK secretion and percentage gallbladder contraction are significantly reduced; 3) percentage postprandial gallbladder emptying is related to the degree of pancreatic exocrine insufficiency.

Gallbladder Motility in Crohn Disease: Influence of Disease Localization and Bowel Resection

BACKGROUND Patients with Crohn disease (CD) have an increased risk of developing gallstones. Among other factors, gallbladder motility may have a role in the pathogenesis of gallstone formation. We have evaluated whether gallbladder motor function is affected in Crohn disease with special emphasis on the influence of disease localization and previous bowel resection. METHODS Thirty-seven patients (20 females and 17 males, age 36 +/- 2 years) with inactive Crohn disease (CDAI < 150) were studied: 15 patients after ileocecal resection and 22 non-operated patients; 12 had small bowel disease and 10 had large bowel disease. Nineteen healthy subjects (10 female; 9 male, age 30 +/- 2 years) served as controls. Gallbladder volumes were measured in the fasting state and at regular intervals for 2 h after ingestion of a solid meal (780 kcal). Blood samples were drawn at regular intervals for determination of cholecystokinin (CCK) and peptide YY (PYY). RESULTS Fasting gallbladder volumes were significantly (P < 0.05) reduced in patients with large bowel disease (20.8 +/- 2.1 ml) or after ileocecal resection (18.3 +/- 2.4 ml) compared to patients with small bowel disease (28.0 +/- 2.1 ml) and controls (27.2 +/- 1.8 ml). Fasting plasma CCK levels were significantly (P < 0.05) higher in patients with large bowel disease or after ileocecal resection compared to patients with small bowel disease and controls. Postprandial gallbladder emptying and endogenous plasma CCK and PYY secretion in patients with Crohn disease were not different from controls. CONCLUSIONS Fasting gallbladder volume is decreased and fasting plasma CCK levels are increased in patients with Crohn disease of the large bowel and patients after ileocecal resection. Postprandial gallbladder motility, CCK and PYY release were not affected in patients with Crohn disease.Background: Patients with Crohn disease (CD) have an increased risk of developing gallstones. Among other factors, gallbladder motility may have a role in the pathogenesis of gallstone formation. We have evaluated whether gallbladder motor function is affected in Crohn disease with special emphasis on the influence of disease localization and previous bowel resection. Methods: Thirty-seven patients (20 females and 17 males, age 36 2 years) with inactive Crohn disease (CDAI < 150) were studied: 15 patients after ileocecal resection and 22 non-operated patients; 12 had small bowel disease and 10 had large bowel disease. Nineteen healthy subjects (10 female; 9 male, age 30 2 years) served as controls. Gallbladder volumes were measured in the fasting state and at regular intervals for 2 h after ingestion of a solid meal (780 kcal). Blood samples were drawn at regular intervals for determination of cholecystokinin (CCK) and peptide YY (PYY).Results: Fasting gallbladder volumes were significantly ( P< 0.05) reduced in patients with large bowel disease (20.8 2.1 ml) or after ileocecal resection (18.3 2.4 ml) compared to patients with small bowel disease (28.0 2.1 ml) and controls (27.2 1.8 ml). Fasting plasma CCK levels were significantly ( P< 0.05) higher in patients with large bowel disease or after ileocecal resection compared to patients with small bowel disease and controls. Postprandial gallbladder emptying and endogenous plasma CCK and PYY secretion in patients with Crohn disease were not different from controls.Conclusions:Fasting gallbladder volume is decreased and fasting plasma CCK levels are increased in patients with Crohn disease of the large bowel and patients after ileocecal resection. Postprandial gallbladder motility, CCK and PYY release were not affected in patients with Crohn disease.

Influence of hyperglycemia on the satiating effect of CCK in humans

In the present study the effects of intraduodenal (i.d.) fat (endogenous CCK) and of CCK infusion on satiety were studied during normo-and hyperglycemic conditions. Eight healthy subjects participated in two protocols consisting of two experiments each. First protocol: (a) normoglycemia (control) with i.d. emulsified fat (i.d. fat) infusion, (b) acute hyperglycemia (HG) with plasma glucose levels stabilized at 15 mmol/L and i.d. fat infusion. In the second protocol the effect of exogenous cholecystokinin (CCK) on satiety was studied during normo- and hyperglycemia. Intraduodenal fat (Intralipid 10%) was infused at a dose of 1 g/h via a nasoduodenal tube in the first protocol, whereas in the second protocol CCK-33 was infused intravenously at a dose of 0.5 IDU/kg x h. Satiety was scored using visual analog scales (VAS). Plasma CCK levels were determined at regular intervals. During infusion of i.d. fat and i.v. CCK the VAS scores of wish to eat, hunger, and prospective feeding decreased significantly (p<0.05) in the normoglycemic experiments. During hyperglycemia satiety did not significantly change in the basal period; however, the scores of wish to eat, hunger, and prospective feeding increased significantly (p<0.05) when i.d. fat or i.v. CCK was administered. Plasma CCK levels in the basal and the stimulated period were not significantly different between normo- and hyperglycemia. In summary, the present study shows that in healthy humans volunteers 1) during normoglycemic conditions satiety can be induced by very low dose of i.d. fat and by CCK infusion, 2) during hyperglycemia the effect of i.d. fat and CCK on satiety are reversed, resulting in increased appetite.

Gallbladder Motility in Response to Sham Feeding and Cholecystokinin in Lean and Obese Subjects

The risk of developing gallstones is increased in obese subjects. We have investigated whether gallbladder motility in obese subjects is different from that in lean control subjects. In 25 healthy non-diabetic obese subjects and 20 age- and sex-matched lean controls, fasting gallbladder volumes, gallbladder contraction in response to cephalic vagal cholinergic stimulation by modified sham feeding (MSF) and to hormonal stimulation with cholecystokinin (CCK) were studied. Gallbladder volumes were measured during a 30-min MSF period followed 1 h later by a 1-hour continuous i.v. infusion of 0.5 IDU/kg ideal weight of CCK-33. Fasting gallbladder volumes were significantly (p < 0.001) larger in obese (47 +/- 4 cm3) compared to lean subjects (24 +/- 2 cm3). Fasting gallbladder volume was correlated with body mass index (p < 0.01). Gallbladder contraction during MSF was significantly (p < 0.01) reduced in obese (12 +/- 2%) compared to lean subjects (22 +/- 3%). CCK infusion, leading to physiological post-prandial plasma CCK levels, induced a significantly (p < 0.001) greater absolute gallbladder contraction in obese (27 +/- 3 cm3) compared to lean subjects (15 +/- 1 cm3) but the percentage gallbladder contraction was in the same range (64 +/- 3% vs. 67 +/- 4%, respectively). In addition, residual gallbladder volumes after CCK infusion were significantly (p < 0.001) larger in obese (15 +/- 2 cm3) than in lean subjects (7 +/- 1 cm3). Two groups of obese subjects were identified: one with increased (>40 cm3) and one with normal (< or = 40 cm3) fasting gallbladder volumes. Only obese subjects with increased fasting volumes showed abnormal gallbladder motility.

Effect of IV Amino Acids on Satiety in Humans

BACKGROUND Parenteral nutrients suppress oral food intake. Separate i.v. infusion of amino acids (IVAA) at high doses affects gastrointestinal motility and secretion. However, little is known on the effects of separate i.v. infusion of amino acids at these high doses on satiety. Therefore, we have studied the effect of two different doses of a commercially available mixed amino acids solution on satiety and food intake. METHODS Six healthy volunteers (ages 20 to 34 years) were studied on three separate occasions in random order during (a) i.v. saline (control), (b) low-dose IVAA ([LDA] 125 mg protein/kg/h, Vamin 18EF; Kabi Pharmacia BV, Woerden, The Netherlands), or (c) high-dose IVAA ([HDA] 250 mg protein/kg/h) for 360 minutes. Subjective criteria such as wish to eat, prospective feeding intentions, and feelings of hunger and fullness were scored on 100-mm visual analog scales at 30-minute intervals. Food preference also was measured every 60 minutes with food selection lists. At the end of the experiment a meal was presented. RESULTS Feelings of fullness were significantly (p < .05) increased during both LDA and HDA. The wish to eat was significantly (p < .05) decreased during HDA compared with control and LDA. Prospective feeding intentions also tended to be reduced during HDA (not significant). Feelings of hunger were not significantly different between the three experiments. Total food selection was significantly (p < .05) decreased during LDA and HDA, mainly because of a significantly (p < .05) decreased preference for fat-rich items. However, the total amount of food consumed at the end of the experiment was not significantly different between the three experiments. CONCLUSIONS The present study shows that in healthy volunteers, IVAA (1) increase satiety ratings, (2) increase feelings of fullness, (3) decrease preprandial food selection, and (4) have no effect on subsequent oral food intake.

Reproducibility of antroduodenal motility during prolonged ambulatory recording

Ambulatory recording of antroduodenal manometry is a novel technique with several advantages over standard stationary manometry recording. Although the feasibility of this technique in clinical practice has been demonstrated, reproducibility of antroduodenal motility recorded by means of ambulatory manometry has not been investigated. To test whether antroduodenal motility recorded by ambulatory manometry is reproducible, we performed two 24-h ambulatory antroduodenal manometry recordings in 18 healthy subjects according to an identical protocol with a 1-week interval. Motility was recorded with a five-channel solid-state catheter. Postprandial motility was recorded after consumption of two test meals and interdigestive motility was recorded nocturnally. Postprandial antroduodenal motor characteristics were identical between the separate recordings. The number and duration of nocturnal cycles of the interdigestive migrating motor complex were also in the same range. Phase III characteristics in general were not different between the two recordings. Only minor alterations were observed in the duration of phase III motor fronts with duodenal onset and in the number of interdigestive cycles concluded by duodenal onset phase III. Parameters obtained by qualitative analysis were comparable between the two recordings. The antroduodenal motility pattern, when measured by ambulatory recording with solid state catheters under standardized conditions, is very reproducible.