Endothelin-1 is a candidate mediating intestinal dysmotility in patients with acute pancreatitis

Efficacy and safety of neostigmine on treating gastrointestinal dysmotility in severe acute pancreatitis patients: study protocol for a randomized controlled trial

BACKGROUND

Acute pancreatitis is a serious threat to human health and gastrointestinal dysmotility is a common complication for acute pancreatitis patients, resulting in delayed feeding, oral feeding intolerance, paralytic ileus, and abdominal compartment syndrome. Currently, there are limited treatment for this complication. Neostigmine is known to increase gastrointestinal motility and has been used to treat gastrointestinal dysmotility after surgery. However, research in treating acute pancreatitis with neostigmine is currently limited.

METHODS

This trial is a randomized, placebo-controlled, double-blinded, mono-centric trial that will test the hypothesis that neostigmine can improve gastrointestinal motility in patients with severe acute pancreatitis. Up to 56 patients will be randomized in this study receiving 0.5 mg/1 ml of neostigmine methylsulfate injection twice per day or 1 ml of saline injection twice per day. Defection time (aim 1), mortality and organ failure (aim 2), borborygmus, starting of enteral nutrition and intra-abdominal pressure (aim 3), and length of ICU and hospital stay (aim 4) will be assessed.

DISCUSSION

Findings from this study will provide data supporting the usage of neostigmine for treating severe acute pancreatitis patients with gastrointestinal dysmotility.

TRIAL REGISTRATION

This study is registered on chictr.org.cn with the identifier as ChiCTR2200058305. Registered on April 5, 2022.

The protective effect of endothelin receptor antagonists against surgically induced impairment of gastrointestinal motility in rats

Endothelin (ET) receptor antagonists: BQ-123 (ET_A), BQ-788 (ET_B), tezosentan (dual ET receptor antagonist) protect against the development of postoperative ileus (POI) evoked by ischemia-reperfusion (I/R). The current experiments explored whether ET antagonists prevent the occurrence of POI evoked by surgical gut manipulation. Intestinal transit was assessed by measuring the rate of dye migration subsequent to skin incision (SI), laparotomy (L), or laparotomy and surgical gut handling (L+M) in diethyl ether anaesthesized rats (E). Experimental animals were randomly sub-divided into two groups depending on the time of recovery following surgery: viz. either 2 or 24 h (early or late phase POI). E and SI did not affect the gastrointestinal (GI) transit. In contrast, L and L+M significantly reduced GI motility in comparison to untreated group (UN). Tezosentan (10 mg/kg), BQ-123 and BQ-788 (1 mg/kg) protected against development of L+M evoked inhibition of intestinal motility in the course of late phase, but not early phase POI. Furthermore, tezosentan alleviated the decrease in the contractile response of the longitudinal jejunal smooth muscle strips to carbachol in vitro induced by L+M. The serum ET(1–21) concentration was not increased in either the early or the late phase POI groups after surgery compared to control animals. This study indicates that delay in the intestinal transit in late phase of surgically induced POI involves an ET-dependent mechanism.

Glucose Variability Measures as Predictors of Oral Feeding Intolerance in Acute Pancreatitis: A Prospective Pilot Study

BACKGROUND

Oral feeding intolerance (OFI) is a common complication in patients with acute pancreatitis (AP). Variations in blood glucose are associated with impaired gastrointestinal function but, to date, measures of glucose variability have not been investigated to predict OFI in patients with AP.

AIM

To investigate the usefulness of several glucose variability measures in predicting the occurrence of OFI early in the course of AP.

METHODS

In this prospective cohort study, six measures of glucose variability were calculated prior to the occurrence of OFI. Multivariate binary logistic regression analyses were conducted, and the diagnostic performance and accuracy of glucose variability measures were assessed.

RESULTS

Of the 95 prospectively enrolled patients, 21 (22%) developed OFI. After adjusting for confounders, admission blood glucose concentration and mean blood glucose concentration were significantly associated with OFI [odds ratio 1.49 (95% confidence interval 1.01-2.20) and odds ratio 1.67 (95% confidence interval 1.07-2.61), respectively]. Both admission blood glucose and mean blood glucose had an area under the curve of 0.83 and positive likelihood ratios of 6.45 and 10.19, respectively. Blood glucose concentration before refeeding, standard deviation of blood glucose concentration, coefficient of variation, and mean amplitude of glycemic excursions were not significantly associated with OFI.

CONCLUSION

In-hospital blood glucose concentrations are associated with subsequent development of OFI in patients with AP. In particular, admission blood glucose and mean blood glucose could be useful predictors of OFI in this setting.

How does cigarette smoking cause acute pancreatitis?

INTRODUCTION

Acute Pancreatitis (AP) is an emerging health problem world-wide and it is a major cause of admissions for gastrointestinal disease in many countries. Amongst the more common causes (alcohol and gallstones), recent evidence has emerged indicating that smoking is an independent risk factor for AP. However, the mechanisms involved in smoking-induced AP have not been completely elucidated. This review puts together all the published evidence in literature to present the clinical and laboratory evidence relating smoking to the causation of AP.

DISCUSSION

The two main metabolites from cigarette smoke, namely nicotine and NNK are able to induce functional and histological changes within the pancreas consistent with AP. The major mechanisms involved include their action on acinar cells and zymogen secretion through pathways involving CCK and the nicotinic preganglionic receptors. Effects on the pancreatic microvasculature may be mediated through the nitric oxide pathway. There is indirect evidence to suggest that nicotine and acrolein may lead to CFTR dysfunction thereby influencing ductal secretion. However, direct evidence for this effect is needed. The effect of cigarette smoke metabolites on stellate cells and the islets warrants further investigation in the context of pathogenesis of AP.

CONCLUSION

Using a step-wise approach, the review revisits the effects of the various metabolites of cigarette smoke on the constituents of the pancreas (exocrine, endocrine, neurohormonal, stellate cells, ductal system) and highlights their proven, and potential, mechanisms in triggering off an attack of AP.

Effect of Nasogastric Tube Feeding vs Nil per Os on Dysmotility in Acute Pancreatitis: Results of a Randomized Controlled Trial

BACKGROUND

Evidence from animal studies suggests that gastrointestinal motility is impaired in acute pancreatitis. Enteral nutrition, and more specifically nasogastric tube feeding, has emerged as a key treatment modality in patients with acute pancreatitis, but its effect on motility has not been investigated in this setting. The aim was to validate the Gastroparesis Cardinal Symptom Index (GCSI) in patients with acute pancreatitis and determine the effect of nasogastric tube feeding on GCSI.

METHODS

The study design was a randomized controlled trial. Patients were allocated to nasogastric tube feeding or nil per os within 24 hours of hospital admission. GCSI data from before randomization to 72 hours after randomization were analyzed. The test-retest reliability analysis was used to calculate Cronbach's α.

RESULTS

Seventeen patients were randomized to nasogastric tube feeding and 18 to nil per os. Overall, the total GCSI score significantly decreased over the study (F = 8.537; P = .001) but was not significantly different between the 2 study groups during hospitalization (F = 1.159; P = .322). However, patients on nasogastric tube feeding did show improved appetite compared with nil per os (F = 3.526; P = .036). The GCSI was found to be a reliable tool in the setting of acute pancreatitis (Cronbach's α = 0.852).

CONCLUSIONS

Nasogastric tube feeding does not appear to affect dysmotility symptoms in acute pancreatitis as measured by the GCSI, although appetite improved. Use of the simple, noninvasive, and inexpensive GCSI tool to evaluate motility is recommended in future clinical trials in pancreatology.

Response of blood endothelin-1 and nitric oxide activity in duodenal ulcer patients undergoing Helicobacter pylori eradication

AIM: To investigate the effect of Helicobacter pylori eradication on endothelin-1 (ET-1) and nitric oxide (NO) in duodenal ulcer (DU) patients.

METHODS: Sixty-six H pylori-infected active DU patients were consecutively enrolled to receive one-week triple therapy (rabeprazole, amoxicillin and metronidazole) and then one-month rabeprazole therapy. They were asked back to determine ulcer and H pylori status using endoscopy one month later. Thirty-seven healthy controls (H pylori +/-: 17/20) were enrolled for comparison. Blood samples were collected in each visit to measure plasma ET-1 and nitrate/nitrite levels using an enzyme immunoassay kit.

RESULTS: Sixty DU patients finished trial per protocol. The ulcer healing and H pylori-eradication rates were 86.7% and 83.3%, respectively. Plasma ET-1 level in DU patients was higher than that of H pylori-negative and positive controls (3.59±0.96 vs 0.89±0.54 vs 0.3±0.2 pg/mL, P<0.01), while nitrate/nitrite levels among them were also significantly different (8.55±0.71 vs 5.27±0.68 vs 6.39±0.92 µmol/L, P<0.05). H pylori eradication diminished ET-1 levels (3.64±0.55 vs 2.64±0.55 pg/mL, P<0.01) but elevated nitrate/nitrite level (8.16±0.84 vs 11.41±1.42 µmol/L, P<0.05).

CONCLUSION: Both plasma ET-1 and nitrate/nitrite levels increase in active DU patients. After an effective H pylori eradication, DU healing is associated with diminished blood ET-1 level and elevated nitrate/nitrite level.

The endothelin-1 receptor antagonists ameliorate histology and ultrastructural alterations in the pancreas and decrease trypsinogen activation in severe taurocholate pancreatitis in rats

The role of potent vasoconstrictor endothelin-1 (ET-1) in acute pancreatitis (AP) remains controversial. The aim was to compare the effect of nonselective ET RA/B (LU-302872) and selective ET RA (LU-302146) antagonists on pancreatic histology, ultrastructure and trypsinogen activation in severe taurocholate AP in rats. Male Wistar rats with AP were treated with an intraperitoneous injection of 1, 5 and 10 mg/kg of body weight of each antagonist at 0, 6, 12 and 18 h after taurocholate administration. After 24 h, the samples of pancreases were taken for histological and ultrastructural examinations and for assessment of trypsinogen activation. Both antagonists, at all investigated doses, decreased the damage to the acinar cells detected in the light microscope and ultrastructurally. Trypsinogen activation increased to 29.7 +/- 3.9% in the AP untreated in comparison to the control group [12.7 +/- 1.4% (P<0.001)]. This increase was attenuated to 13.8 +/- 2.2% in AP treated with a high dose of the nonselective antagonist and to 8.4 +/- 1.7% with low dose of selective antagonist. The obtained results indicate that ET-1 could participate in the damage to the pancreas during AP. Both antagonists of ET-1 receptors exerted a similar beneficial effect on the morphological changes of the pancreas in AP. One of the probable mechanism could be the attenuation of trypsinogen activation.

Endothelin-1 stimulates sphincter of Oddi motility and decreases trans-sphincteric flow: a possible mechanism contributes to cholestasis in disease states

Endothelin-1 (ET-1) is a potent stimulator of gallbladder contractility. Its role in modulation of sphincter of Oddi (SO) motility and trans-sphincteric flow (TSF) has not been evaluated. To characterize the effects of ET-1 on SO motility and TSF, 10 anaesthetized Australian possums (in vivo, n = 6) were given graded doses of ET-1 (5-200 pmol kg-1) via closed intra-arterial injection. Blood pressure, TSF and SO motility (basal pressure, phasic amplitude, contraction frequency) were analysed. For in vitro studies, eight SO rings were subjected to 10-12-10-7 mol L-1 cumulative concentrations of ET-1 in organ bath and SO motility was measured. Data are expressed as mean +/- SEM. Statistical analysis used anova. ET-1 induced a dose-related increase in blood pressure with a maximal increase of 37.5 +/- 2.5 mmHg at 200 pmol kg-1, (P < 0.001). ET-1 also increases SO basal pressure (P < 0.001) and contraction frequency (P < 0.0001). However, the contraction amplitude was not significantly affected. ET-1 decreased TSF in a dose-related manner (P < 0.001) with cessation of TSF at the highest dose (P < 0.001). In vitro studies showed a significant increase in mean SO motility index, and frequency of contractions at higher ET-1 concentrations (10-9-10-7 mol L-1). ET-1 is a potent stimulator of SO motility resulting in a reduction in TSF.

The role of the intestine in the pathophysiology and management of severe acute pancreatitis

BACKGROUND

The outcome of severe acute pancreatitis has scarcely improved in 10 years. Further impact will require new paradigms in pathophysiology and treatment. There is accumulating evidence to support the concept that the intestine has a key role in the pathophysiology of severe acute pancreatitis which goes beyond the notion of secondary pancreatic infection. Intestinal ischaemia and reperfusion and barrier failure are implicated in the development of multiple organ failure.

DISCUSSION

Conventional management of severe acute pancreatitis has tended to ignore the intestine. More recent attempts to rectify this problem have included 1) resuscitation aimed at restoring intestinal blood flow through the use of appropriate fluids and splanchnic-sparing vasoconstrictors or inotropes; 2) enteral nutrition to help maintain the integrity of the intestinal barrier; 3) selective gut decontamination and prophylactic antibiotics to reduce bacterial translocation and secondary infection. Novel therapies are being developed to limit intestinal injury, and these include antioxidants and anti-cytokine agents. This paper focuses on the role of the intestine in the pathogenesis of severe acute pancreatitis and reviews the implications for management.

The effect of endothelin-1 receptor antagonists in acute experimental pancreatitis in the rats

The relative role of endothelin-1 receptors, ET(A) and ET(B) blockade in acute pancreatitis (AP) remains controversial. The aim of the study was to compare the effect of nonselective ET(A/B) antagonist (LU 302872) and selective ET(A)antagonist (LU 302146) in severe taurocholate AP in rats. Male Wistar rats with AP were treated with increasing doses: 1, 5 or 10 mg/kg b.w. of antagonists i.p. at 0, 6, 12, 18 h after induction of AP. In 24 h survivors, free active trypsin (FAT) and total potential trypsin (TPT), chymotrypsin and lipase in 12,000 x g supernatants of the pancreases were assayed. The index of trypsinogen activation (% FAT/TPT) was elevated in untreated AP to 29.2 +/- 5.0 vs 5.4 +/- 0.9 in the control (p < 0.001). ET(A/B) antagonist at increasing doses, diminished this index to 9.8 +/- 2.7, 10.3 +/- 1.6 and 10.1 +/- 2.0 respectively (p < 0.005). ET(A) antagonist reduced % FAT/TPT ratio to 10.6 +/- 1.9 (p < 0.005), 13.4 +/- 0.5 (p < 0.001) and 10.2 +/- 2.4 (p < 0.005) at respective doses. Both antagonists to a similar degree reduced the histological scores of inflammation, hemorrhages and necrosis. The increase in chymotrypsin and lipase activities after 24 h was not significant. In conclusion, both nonselective ET(A/B) and selective ET(A) antagonists attenuated to similar degree the augmented trypsinogen activation and pancreatic injury in taurocholate acute experimental pancreatitis in rats. Endothelin-1 receptor antagonists could be beneficial in the course of acute pancreatitis by the attenuation of trypsinogen activation.

Gastrointestinal dysmotility in patients with acute pancreatitis

BACKGROUND AND AIMS

Gut-origin bacterial translocation is one of the major causes of pancreatic necrotic tissue infection in patients with severe acute pancreatitis (SAP). The gastrointestinal dysmotility is supposed to be the fundamental event in this process. To test this hypothesis, alteration of colonic transit time (CTT) in patients with acute pancreatitis (AP) was investigated. In order to evaluate the possible mechanisms involved in gastrointestinal dysmotility, changes of serum motilin (MTL), cholecystokinin (CCK) and vasoactive intestinal peptide (VIP) in patients with AP were also measured.

METHODS

Twenty-four non-consecutive patients with AP and 25 controls were included in this study. The diagnosis of AP was based upon clinical features, biochemical indices and radiological investigation. The severity of AP at admission was evaluated according to the APACHE-II and Balthazar computed tomography (CT) scoring system. Total and segmental CTT in patients with AP and in controls were determined by ingestion of radiopaque markers (Sitzmarks(R)) according to the modified Metcalf's method. Meanwhile, serum MTL and CCK were assessed using radioimmunoassay (RIA), and serum VIP was measured by using ELISA in this study.

RESULTS

Compared to the controls, the total CTT and segmental CTT (mainly right and left hemicolon) were prolonged significantly in 10 patients with SAP and 14 patients with MAP; P < 0.05. Moreover, the total CTT and segmental CTT were markedly more delayed in patients with SAP than in patients with MAP; P < 0.05. The concentrations of serum MTL and CCK were significantly decreased in both MAP and SAP patients compared with those in controls (P < 0.01). There was no significant differences in serum MTL and CCK levels between the SAP and MAP groups; P > 0.05. In addition, the concentration of serum VIP was increased in AP patients, and it reached statistical significance in patients with SAP (P < 0.05).

CONCLUSIONS

In conclusion, gastrointestinal dysmotility often occurred in patients with AP, especially more severely in SAP patients. One of the possible mechanisms might be related to the synergic actions of gut hormones, such as MTL, CCK and VIP.

Delayed gastrointestinal transit in patients with hepatocellular carcinoma

BACKGROUND AND AIM

Disturbed gastrointestinal (GI) motility exists in cirrhotic patients; however, less is known about the character of GI transit in hepatocellular carcinoma (HCC) patients. It is interesting to study the GI transit in HCC patients and to explore the patient factors modulating GI transit.

METHODS

A non-invasive hydrogen breath test, which measured the orocecal transit time (OCTT), was used to study GI transit in 40 HCC patients, 20 cirrhotics and 40 age- and sex-matched healthy volunteers with normal bowel habits. Meanwhile, their clinical manifestations and various blood parameters, such as platelet count, prothrombin time, erythrocyte sedimentation rate etc. were collected. The plasma endothelin-1 and nitrate/nitrite levels were also measured.

RESULTS

The OCTT were delayed in HCC and cirrhotic patients compared with controls (116.3 +/- 7.8 and 104.5 +/- 10.6 vs 75.3 +/- 5.1 min, P < 0.05). Neither the severity of liver damage, presence of ascites, tumor size, portal hypertension, nor various blood parameters, such as nitrate/nitrite, endothelin-1, platelet count etc., had any influence on GI transit. Only serum alpha-fetoprotein levels exhibited a trend toward positive correlation with the OCTT (r = 0.271, P = 0.091).

CONCLUSIONS

Hepatocellular carcinoma patients have delayed GI transit. The confounding factor responsible for the disturbance of GI transit in HCC patients needs further exploration.

Regulation of guinea pig intestinal peristalsis by endogenous endothelin acting at ET(B) receptors

BACKGROUND & AIMS

Endothelins are expressed in many enteric neurons of the gut. Because activation of endothelin ET(A) and ET(B) receptors is known to alter intestinal muscle activity, the effect of ET(A) and ET(B) receptor agonists and antagonists on propulsive peristalsis was examined.

METHODS

Repetitive peristalsis in fluid-perfused segments of the guinea pig isolated small intestine was elicited by a rise of the intraluminal pressure and recorded via the pressure changes generated by the peristaltic waves.

RESULTS

Endothelin 1 (0.3-10 nmol/L added to the organ bath) stimulated peristalsis as shown by a decrease in the pressure threshold at which peristaltic waves were triggered, whereas the endothelin analog sarafotoxin 6c (0.3-10 nmol/L) inhibited peristalsis as reflected by an increase in the pressure threshold. The ET(A) receptor antagonist BQ-123 (3 micromol/L) converted the properistaltic action of endothelin 1 to an antiperistaltic action, whereas the ET(B) receptor antagonist BQ-788 (3 micromol/L) prevented the antiperistaltic action of sarafotoxin 6c. BQ-788, but not BQ-123, facilitated peristalsis on its own. Additional experiments indicated that the properistaltic action of endothelin 1 is mediated by enteric neurons, whereas the peristaltic motor effects of sarafotoxin 6c and BQ-788 are caused by a direct action on the muscle.

CONCLUSIONS

ET(A) receptor activation stimulates, whereas ET(B) receptor activation inhibits, intestinal peristalsis. The ability of BQ-788 to facilitate peristalsis per se points to a physiologic role of ET(B) receptors in peristaltic motor regulation.