A double-blind trial of synthetic salmon calcitonin in the treatment of acute pancreatitis

Historical review of our knowledge of acute pancreatitis

Acute pancreatitis is one of most common causes of consultation due to abdominal pain in medical emergency units and it requires hospital admission. Although the majority of cases are mild and patients tend to recover quickly, a small percentage of cases is severe, with mortality in the region of 5-10%. This historical review considers how our understanding of this disease has changed since it was first described in 1579 thanks to the contributions of renowned experts such as Nicolaes Tulp, Reginald Fitz, Nicholas Senn and many others who, through their expertise and dedication, have improved the survival of patients with this disease.

Pharmacological interventions for acute pancreatitis

BACKGROUND

In people with acute pancreatitis, it is unclear what the role should be for medical treatment as an addition to supportive care such as fluid and electrolyte balance and organ support in people with organ failure.

OBJECTIVES

To assess the effects of different pharmacological interventions in people with acute pancreatitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 9), MEDLINE, Embase, Science Citation Index Expanded, and trial registers to October 2016 to identify randomised controlled trials (RCTs). We also searched the references of included trials to identify further trials.

SELECTION CRITERIA

We considered only RCTs performed in people with acute pancreatitis, irrespective of aetiology, severity, presence of infection, language, blinding, or publication status for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and extracted data. We did not perform a network meta-analysis as planned because of the lack of information on potential effect modifiers and differences of type of participants included in the different comparisons, when information was available. We calculated the odds ratio (OR) with 95% confidence intervals (CIs) for the binary outcomes and rate ratios with 95% CIs for count outcomes using a fixed-effect model and random-effects model.

MAIN RESULTS

We included 84 RCTs with 8234 participants in this review. Six trials (N = 658) did not report any of the outcomes of interest for this review. The remaining 78 trials excluded 210 participants after randomisation. Thus, a total of 7366 participants in 78 trials contributed to one or more outcomes for this review. The treatments assessed in these 78 trials included antibiotics, antioxidants, aprotinin, atropine, calcitonin, cimetidine, EDTA (ethylenediaminetetraacetic acid), gabexate, glucagon, iniprol, lexipafant, NSAIDs (non-steroidal anti-inflammatory drugs), octreotide, oxyphenonium, probiotics, activated protein C, somatostatin, somatostatin plus omeprazole, somatostatin plus ulinastatin, thymosin, ulinastatin, and inactive control. Apart from the comparison of antibiotics versus control, which included a large proportion of participants with necrotising pancreatitis, the remaining comparisons had only a small proportion of patients with this condition. Most trials included either only participants with severe acute pancreatitis or included a mixture of participants with mild acute pancreatitis and severe acute pancreatitis (75 trials). Overall, the risk of bias in trials was unclear or high for all but one of the trials.

SOURCE OF FUNDING

seven trials were not funded or funded by agencies without vested interest in results. Pharmaceutical companies partially or fully funded 21 trials. The source of funding was not available from the remaining trials.Since we considered short-term mortality as the most important outcome, we presented only these results in detail in the abstract. Sixty-seven studies including 6638 participants reported short-term mortality. There was no evidence of any differences in short-term mortality in any of the comparisons (very low-quality evidence). With regards to other primary outcomes, serious adverse events (number) were lower than control in participants taking lexipafant (rate ratio 0.67, 95% CI 0.46 to 0.96; N = 290; 1 study; very low-quality evidence), octreotide (rate ratio 0.74, 95% CI 0.60 to 0.89; N = 770; 5 studies; very low-quality evidence), somatostatin plus omeprazole (rate ratio 0.36, 95% CI 0.19 to 0.70; N = 140; 1 study; low-quality evidence), and somatostatin plus ulinastatin (rate ratio 0.30, 95% CI 0.15 to 0.60; N = 122; 1 study; low-quality evidence). The proportion of people with organ failure was lower in octreotide than control (OR 0.51, 95% CI 0.27 to 0.97; N = 430; 3 studies; very low-quality evidence). The proportion of people with sepsis was lower in lexipafant than control (OR 0.26, 95% CI 0.08 to 0.83; N = 290; 1 study; very low-quality evidence). There was no evidence of differences in any of the remaining comparisons in these outcomes or for any of the remaining primary outcomes (the proportion of participants experiencing at least one serious adverse event and the occurrence of infected pancreatic necrosis). None of the trials reported heath-related quality of life.

AUTHORS' CONCLUSIONS

Very low-quality evidence suggests that none of the pharmacological treatments studied decrease short-term mortality in people with acute pancreatitis. However, the confidence intervals were wide and consistent with an increase or decrease in short-term mortality due to the interventions. We did not find consistent clinical benefits with any intervention. Because of the limitations in the prognostic scoring systems and because damage to organs may occur in acute pancreatitis before they are clinically manifest, future trials should consider including pancreatitis of all severity but power the study to measure the differences in the subgroup of people with severe acute pancreatitis. It may be difficult to power the studies based on mortality. Future trials in participants with acute pancreatitis should consider other outcomes such as complications or health-related quality of life as primary outcomes. Such trials should include health-related quality of life, costs, and return to work as outcomes and should follow patients for at least three months (preferably for at least one year).

Acute Pancreatitis: Work-up and Management

Acute pancreatitis is still a common clinical entity that causes significant morbidity and mortality. The most common etiological associations include chronic al coholism, biliary tract disease, iatrogenic (e.g., endo scopic retrograde cholangiopancreatography-induced), hypertriglyceridemia, and idiopathic varieties. New radiological techniques such as dynamic pancreatog raphy appear to be useful in diagnosing and determin ing the extent of necrotizing pancreatitis. Biochem ical variables such as the C-reactive protein and the trypsinogen-activated peptide seem promising in de tecting severe disease within the first few days of hospi talization. Computed tomographic-guided percutane ous aspiration of phlegmonous pancreatitis may be helpful in differentiating infected from noninfected masses. Although current studies have not identified any pharmacological agent as efficacious in improving sur vival, emergency sphincterotomy and removal of im pacted gallstones in severe gallstone pancreatitis may be beneficial in this regard. Prolonged (i.e., 7 day) perito neal dialysis may reduce the severity of pancreatic sep sis. Surgical drainage of infected fluid collections such as abscesses is a well-accepted adjunct to medical therapy. Surgical necrosectomy for necrotizing pancreatitis, however, which is advocated in some aggressive surgi cal units, is not yet commonplace and its role needs to be determined in controlled studies.

Pharmacologic therapy for acute pancreatitis

While conservative management such as fluid, bowel rest, and antibiotics is the mainstay of current acute pancreatitis management, there is a lot of promise in pharmacologic therapies that target various aspects of the pathogenesis of pancreatitis. Extensive review of preclinical studies, which include assessment of therapies such as anti-secretory agents, protease inhibitors, anti-inflammatory agents, and anti-oxidants are discussed. Many of these studies have shown therapeutic benefit and improved survival in experimental models. Based on available preclinical studies, we discuss potential novel targeted pharmacologic approaches that may offer promise in the treatment of acute pancreatitis. To date a variety of clinical studies have assessed the translational potential of animal model effective experimental therapies and have shown either failure or mixed results in human studies. Despite these discouraging clinical studies, there is a great clinical need and there exist several preclinical effective therapies that await investigation in patients. Better understanding of acute pancreatitis pathophysiology and lessons learned from past clinical studies are likely to offer a great foundation upon which to expand future therapies in acute pancreatitis.

Clinical pancreatology I: Pancreatic medical history

The present article and subsequent reviews will not be to report all what has been published, but rather to give an introduction samples that hopefully make the reader eager to read the whole article or articles with "a taste of clinical pancreatology in 2010". The main sources of literatures were PubMed, and the additional Journals such as Pancreas, Pancreatology and Journal of the Pancreas were also scrutinized. Only some full articles in almost all languages were included in the review, other articles, however, that were too superficial or too poor in other ways, were omitted, and the publications of non-human study were excluded.

Treatment of acute pancreatitis: an attempted historical review

This attempt at a historical review of the treatment of acute pancreatitis summarizes the findings of studies carried out in decades long past and shows their impact on the therapy of this disease today. It identifies in retrospect the correct avenues of research and the blind alleys, and describes the ebb and flow of interest in various forms of management. Acquaintance with the work of previous investigators may prevent the unnecessary rediscovery of old principles of treatment. Not all of the studies discussed can be found with search engines: they come from the author's personal library, collected over his 40 years as an active pancreatologist, and from the knowledge of the early literature bequeathed to him by his teachers and mentors.

Pharmacological prevention and treatment of acute pancreatitis: where are we now?

Acute pancreatitis is a disease of increasing prevalence, unchanged mortality over many decades, and limited treatment strategies. Progress has been made in developing therapies that reduce the rate of endoscopic retrograde cholangiopancreatography (ERCP)-associated pancreatitis and in preventing infected pancreatic necrosis with intravenous carbapenems. Attempts at reducing pancreatic enzyme output or inhibiting the activity of digestive enzyme proteases have not yielded encouraging results - nor have anti-inflammatory strategies for the treatment of acute pancreatitis been found to be effective so far. Future therapeutic options that are presently being developed or under investigation attempt to restore pancreatic secretory function, interfere with inflammatory pathways in a more effective manner, or inhibit digestive enzyme proteases more selectively.

Dose-response for inhibition by amylin of cholecystokinin-stimulated secretion of amylase and lipase in rats

BACKGROUND AND AIMS

The neuroendocrine hormone amylin, cosecreted with insulin from pancreatic beta-cells in response to nutrient ingestion, has several physiologic actions to limit the rate of nutrient uptake, including the slowing of gastric emptying.

METHODS

To investigate whether amylin might modulate digestive enzyme secretion from the exocrine pancreas, anesthetized Sprague Dawley rats were cannulated via the pancreatic duct and the secretory response (flow, amylase and lipase) to cholecystokinin (1 microg s.c.) was measured in the absence and in the presence of 0.1, 0.3 and 1 microg s.c. doses of amylin.

RESULTS

Amylin alone did not affect pancreatic secretion, but it dose-dependently inhibited cholecystokinin-stimulated amylase secretion by up to 58% and lipase secretion by up to 67%. The ED50's for these responses were 0.21 microg+/-0.18 log and 0.11 microg+/-0.05 log, respectively, doses that result in excursions of plasma amylin concentration that are within the reported physiological range. Amylin did not evoke cell signalling in the Ar42j model of pancreatic acinar cells, and responses to amylin were not observed in either Ar42j cells or isolated pancreatic acini in a microphysiometer indicating that the effect of amylin was indirect.

CONCLUSIONS

Inhibition of stimulated pancreatic enzyme secretion is likely to be a physiological, extrapancreatic, action of amylin. Amylinergic mechanisms modulating both gastric emptying and pancreatic enzyme secretion may thus match, respectively, the appearance of substrate and enzymes in the gut lumen.

Effects on digestive secretions

Rat amylin subcutaneously injected into rats dose-dependently inhibits pentagastrin-stimulated gastric acid secretion and protects the stomach from ethanol-induced gastritis. The ED50s for these actions (0.050 and 0.036 microg, respectively) are the lowest for any dose-dependent effect of amylin thus far described, and their similar potencies are consistent with a mechanistic (causal) association. At higher amylin doses, inhibition of gastric acid secretion was almost complete (93.4%). Gastric injury (measured by a subjective analog scale) was inhibited by up to 67%. The observation that effective doses of amylin result in plasma concentrations of 7-10 pM (i.e., within the reported range; Pieber et al., 1994) supports the interpretation that inhibition of gastric acid secretion and maintenance of gastric mucosal integrity are physiological actions of endogenous amylin. The pharmacology of these responses fits with one mediated via amylin-like receptors. Rat amylin inhibited CCK-stimulated secretion of pancreatic enzymes,amylase, and lipase by up to approximately 60% without having significant effect in the absence of CCK. ED50s for the effect were in the 0.1-0.2 microg range, calculated to produce plasma amylin excursions within the physiological range. Effects of informative ligands are consistent with the concept of amylin receptor mediation. Amylin was effective in ameliorating the severity of pancreatitis in a rodent model. The amylin analog pramlintide inhibited gallbladder emptying in mice as measured by total weight of acutely excised gallbladders. Amylin inhibition of gastric acid secretion, pancreatic enzyme secretion, and bile secretion likely represents part of an orchestrated control of nutrient appearance. Modulation of digestive function fits with a general role of amylin in regulating nutrient uptake. Rate of ingestion, rate of release from the stomach, and rate of digestion of various food groups appear to be under coordinate control.

Optimising outcomes in acute pancreatitis

Acute pancreatitis is a common cause for presentation to emergency departments. Common causes in Western societies include biliary pancreatitis and alcohol (the latter in the setting of chronic pancreatitis). Acute pancreatitis also follows endoscopic retrograde pancreatography in 5 to 10% of patients, a group that could potentially benefit from prophylactic treatment. Although episodes of pancreatitis usually run a relatively benign course, up to 20% of patients have more severe disease, and this group has significant morbidity and mortality. Therefore, attempts have been made to identify, at or soon after presentation, those patients likely to have a poor outcome and to channel resources to this group. The mainstay of treatment is aggressive support and monitoring of those patients likely to have a poor outcome. Pharmacotherapy for acute pancreatitis (both prophylactic and in the acute setting) has been generally disappointing. Efforts initially focused on protease inhibitors, of which gabexate shows some promise as a prophylactic agent. Agents that suppress pancreatic secretion have produced disappointing results in human studies. Infection of pancreatic necrosis is associated with high mortality and requires surgical intervention. In view of the seriousness of infected necrosis, the use of prophylactic antibacterials such as carbapenems and quinolones has been advocated in the setting of pancreatic necrosis. Similarly, data are accumulating to support the use of prophylactic antifungal therapy. Recently, it has become apparent that the intense inflammatory response associated with acute pancreatitis is responsible for much of the local and systemic damage. With this realisation, future efforts in pharmacotherapy are likely to focus on suppression or antagonism of pro-inflammatory cytokines and other inflammatory mediators. Similarly, animal studies have demonstrated the importance of oxidative stress in acute pancreatitis, although to date there is a paucity of information regarding the efficacy of antioxidants. Although the clinical course for most patients with acute pancreatitis is mild, severe acute pancreatitis continues to be a clinical challenge, requiring a multidisciplinary approach of physician, intensivist and surgeon.

Acute pancreatitis: nonsurgical management

The care of patients with severe acute pancreatitis is complex. Although numerous medical therapies have been proposed, few interventions have been shown to be of benefit in patients with severe disease. This review summarizes the nonoperative management of patients with acute pancreatitis, including therapies shown to be of little value, the role of antibiotics in patients with acute pancreatitis, the importance of monitoring and supportive care, and the rationale of endoscopic and surgical intervention.

A double-blind, placebo-controlled, dose-finding trial of intermittent nasal salmon calcitonin for prevention of postmenopausal lumbar spine bone loss

PURPOSE

Nasal administration of salmon calcitonin (SCT) has been suggested for preventing trabecular bone loss during the first years following the menopause, but no conclusive evidence has appeared about the minimal effective dose. Since nasal calcitonin is highly expensive, it makes sense to define this dose.

PATIENTS AND METHODS

We performed a double-blind, placebo-controlled, randomized, single-center study with a 3-arm parallel-group design. The subjects were 251 healthy women who had experienced natural menopause within the past 6 to 72 months and were not affected by any diseases or treatments that interfere with calcium metabolism. They were randomly allocated in groups of 6 to receive intranasal SCT 50 IU (n = 84), SCT 200 IU (n = 84), or placebo (n = 83). All treatments were given on 5 consecutive days per week. Statistical analysis was based on two populations: intention-to-treat (IT) and valid completers (VC). The main assessments performed were bone mineral density of the lumbar spine (LSBMD) and biochemical parameters reflecting bone turnover (serum alkaline phosphatase, urinary calcium/creatinine, and hydroxyproline/creatinine ratios).

RESULTS

Changes over the treatment period were comparable in the IT and VC populations. In the group receiving the placebo, LSBMD decreased from baseline to end point by a mean of 6.28% (95% confidence interval [CI] -7.69 to -4.89) in the IT population and 6.98% (95% CI -8.86 to -5.11) in the VC population (P = 0.0001, end LSBMD versus baseline LSBMD). LSBMD increased slightly with the 50-IU/d dose of SCT, by 0.82% (95% CI -0.26 to 1.89) in the IT population, and 0.51% (95% CI -0.69 to 1.72) in the VC (P = NS, versus baseline). Subjects who received SCT 200 IU/d experienced significant increases of 2.03% (95% CI 0.92 to 3.15) in the IT population and 2.26% (95% CI 1.01 to 3.51) in the VC (both P = 0.001). The difference between the evolution of the combined groups receiving nasal SCT and the group treated with the placebo was highly significant (P = 0.0001). No significant changes were recorded in biochemical parameters reflecting bone turnover.

CONCLUSIONS

SCT 50 IU/d administered nasally and intermittently appears to prevent lumbar bone loss in nonobese early postmenopausal women.

Exocrine pancreatic function in the early phase of human acute pancreatitis

BACKGROUND

Little is known about exocrine pancreatic function during human acute pancreatitis. We aimed to evaluate interdigestive exocrine pancreatic secretion and pancreatic polypeptide (PP) release during the early phase of acute pancreatitis in humans.

METHODS

Eight patients with acute pancreatitis (six biliary, one alcoholic, and one idiopathic acute pancreatitis) were studied within 72 h from the onset of symptoms. Four patients had necrotizing and four had edematous acute pancreatitis. Normal values were obtained from 26 normal subjects matched by sex and age. Interdigestive pancreatic secretion was studied by a duodenal intubation perfusion technique. Enzyme output was calculated for consecutive 15-min periods over 3-4 h and expressed as units per hour within a secretion cycle and units per hour around a secretion peak. Plasma PP concentrations were measured by radioimmunoassay in 15-min intervals.

RESULTS

All variables studied were similar in patients with acute pancreatitis and in controls. PP release in acute pancreatitis was maintained in a normal cyclical pattern closely related to the secretory cycles.

CONCLUSIONS

Interdigestive exocrine pancreatic secretion in the early phase of mild to moderate acute pancreatitis in humans remains within the normal range. This finding provides a rational basis for early therapeutic inhibition of pancreatic secretion in human acute pancreatitis.

Inflammatory mediators in acute pancreatitis

The cellular events leading to acute pancreatitis are not well defined and the mechanism by which known aetiological factors initiate the disease process remains to be established. Inflammatory mediators have recently been implicated as potential early markers of disease severity and may help elucidate the pathophysiology of the disease. Oxidative stress is emerging as a common effector of the acinar cell injury in experimental acute pancreatitis and clinical findings indicate that neutrophil activation is a significant early event. In common with neutrophil-mediated tissue damage in states of tissue hypoperfusion, acute pancreatitis shows many features of an ischaemia-reperfusion injury. Increased levels of phospholipase A2 have been demonstrated; this enzyme induces synthesis of prostaglandins and platelet-activating factor, a potent inflammatory mediator. New therapeutic approaches to the complications of acute pancreatitis may be through manipulation of such mediators of inflammation.

Gabexate mesilate in human acute pancreatitis. German Pancreatitis Study Group

BACKGROUND

A multicenter controlled study was performed to evaluate the effect of high doses of the low molecular weight protease inhibitor gabexate mesilate on mortality and complications associated with moderate and severe acute pancreatitis.

METHODS

Two hundred twenty-three patients from 29 hospitals were entered in the randomized, double-blind trial. Admission to the study was based on strict criteria excluding mild acute pancreatitis. The patients received placebo or 4 g gabexate mesilate per day intravenously for 7 days. All patients were followed up for 90 days after randomization. The analysis was based on 14 complications, including death.

RESULTS

There was no statistical difference in either mortality or complications associated with acute pancreatitis between the placebo and gabexate mesilate groups.

CONCLUSIONS

The results show that gabexate mesilate was not effective in preventing complications and mortality in acute pancreatitis.

Cloning, characterization, and expression of a human calcitonin receptor from an ovarian carcinoma cell line

A human ovarian small cell carcinoma line (BIN-67) expresses abundant calcitonin (CT) receptors (CTR) (143,000 per cell) that are coupled, to adenylate cyclase. The dissociation constants (Kd) for the CTRs on these BIN-67 cells is approximately 0.42 nM for salmon CT and approximately 4.6 nM for human CT. To clone a human CTR (hCTR), a BIN-67 cDNA library was screened using a cDNA probe from a porcine renal CTR (pCTR) that we recently cloned. One positive clone of 3,588 bp was identified. Transfection of this cDNA into COS cells resulted in expression of receptors with high affinity for salmon CT (Kd = approximately 0.44 nM) and for human CT (Kd = approximately 5.4 nM). The expressed hCTR was coupled to adenylate cyclase. Northern analysis with the hCTR cDNA probe indicated a single transcript of approximately 4.2 kb. The cloned cDNA encodes a putative peptide of 490 amino acids with seven potential transmembrane domains. The amino acid sequence of the hCTR is 73% identical to the pCTR, although the hCTR contains an insert of 16 amino acids between transmembrane domain I and II. The structural differences may account for observed differences in binding affinity between the porcine renal and human ovarian CTRs. The CTRs are closely related to the receptors for parathyroid hormone-parathyroid hormone-related peptide and secretin; these receptors comprise a distinct family of G protein-coupled seven transmembrane domain receptors. Interestingly, the hCTR sequence is remotely related to the cAMP receptor of Dictyostelium discoideum (21% identical), but is not significantly related to other G protein-coupled receptor sequences now in the data bases.

New perspectives on acute pancreatitis

The past decade has witnessed considerable changes in the clinical management of acute pancreatitis. Simultaneously, significant advances have been made in understanding the cellular and biochemical events involved in the initiation of this disease. This review summarizes recent clinical and scientific progress regarding acute pancreatitis and suggests areas for future investigation.

Clinical usefulness of polymorphonuclear elastase in predicting the severity of acute pancreatitis: results of a multicentre study

The usefulness and clinical applicability of quantitative plasma polymorphonuclear elastase determinations in the diagnosis of the severity of acute pancreatitis was analysed in a multicentre study and was compared with the usual prognostic systems of Ranson and Osborne et al. The study comprised 182 patients, 154 with a mild episode of acute pancreatitis and 28 with a severe episode, defined by the development of major complications or a fatal outcome. In the severe cases neutrophilic elastase reached significantly higher values than in mild cases (P less than 0.001) by the time the patient was admitted (2-12 h after the onset of the disease), reflecting considerable leucocyte activation. The sensitivity and specificity of this test are therefore greater than 90 per cent, with a positive severity predictive value of almost 80 per cent at the time of admission and 97 per cent after 24 h, and a negative predictive value of approximately 98 per cent. In addition to requiring 48 h for evaluation, the usual prognostic systems show a sensitivity of 77-85 per cent, a specificity of 70-77 per cent, a positive predictive value of 40-48 per cent, and a negative predictive value of 92-95 per cent, clearly lower than those obtained with leucocyte elastase. Polymorphonuclear elastase is therefore a very early and reliable marker in the diagnosis of the severity of acute pancreatitis, in addition to being easily adaptable to the routine of any hospital laboratory.

Current concepts in the management of pancreatitis

Acute pancreatitis is often a mild, self-limiting illness that responds to simple supportive therapy in the form of intravenous fluids and analgesics. More severe attacks may result in organ failure or pancreatic necrosis. Such patients should be identified early in the course of an attack and actively monitored within an intensive care unit or high dependency area. Supportive therapy remains the basis of management. Attention to the adequacy of the fluid balance and oxygenation are of prime importance and supportive therapy may include inotropic support, assisted ventilation and renal dialysis. Pancreatic necrosis should be sought by contrast-enhanced computed tomography (CT) scanning, and surgical intervention may be required if the patient's clinical condition continues to deteriorate. Surgery should ideally be delayed until the second or subsequent week when necrosectomy (debridement of necrotic pancreatic tissue) may be possible rather than formal pancreatic resection. The role of various drugs to suppress pancreatic secretion and inhibit pancreatic enzymes, although shown to be consistently effective in experimental pancreatitis, has not been established by controlled clinical trials in humans. Recent controlled studies examining peritoneal lavage in humans have failed to confirm the beneficial results suggested in earlier studies. Early endoscopic sphincterotomy for patients with severe gallstone pancreatitis and ductal calculi has been reported to reduce mortality and morbidity in one controlled clinical trial and may prove to be an important advance.

Pancreatic exocrine secretion in acute experimental pancreatitis

Little is known about exocrine pancreatic secretory function in patients with acute pancreatitis, in particular during the early phase of the disease. Therefore, this study evaluates basal and stimulated pancreatic secretion in vivo and in vitro in four different models of acute pancreatitis which reflect its clinical spectrum of severity: (a) edematous pancreatitis induced in the rat by seven IP injections of 50 micrograms/kg cerulein at hourly intervals; (b) edematous pancreatitis with cellular necrosis induced in the mouse by seven IP injections of 50 micrograms/kg cerulein at hourly intervals; (c) hemorrhagic pancreatitis induced in the mouse by feeding an ethionine-supplemented, choline-deficient diet for 66 hours; and (d) hemorrhagic pancreatitis induced in the rat by retrograde infusion of 0.6 mL 5% sodium taurocholate into the pancreatic duct. Secretory studies were performed in vivo and in vitro at various times after onset of pancreatitis. The results show that the exocrine pancreas gradually became resistant to cholecystokinin stimulation after the onset of acute pancreatitis in all four animal models. Cholecystokinin-stimulated secretion was almost abolished in vivo and in vitro at the time of maximal histological damage. In vivo basal secretion was also reduced. In vitro there was an increase in basal release of amylase from isolated acini that was not caused by an increase in luminal secretion but by enzyme release from damaged cells. The time course of improvement of secretory function after acute experimental pancreatitis depended on the severity of the pancreatitis. Recovery of secretory capacity took longer after severe necrotizing pancreatitis than after edematous pancreatitis. However, the ultimate resolution of secretory function was remarkable, in particular after severe hemorrhagic pancreatitis. In all four models, secretory capacity became indistinguishable from normal before the morphological alterations had completely resolved. The present experimental data suggest that pancreatic secretion, and particularly pancreatic secretory response to cholecystokinin, may also be reduced in patients early after the onset of acute pancreatitis.

Acute pancreatitis at its centenary. The contribution of Reginald Fitz

1989 represents the 100th anniversary of Reginald Fitz's initial characterization of acute pancreatitis. Our current understanding of this disease has advanced little beyond Fitz's early description. While survival from pancreatitis has improved largely through advancements in critical care techniques, no medical or surgical therapy exists that can limit pancreatic autodigestion and inflammation. Recent investigations have suggested that pancreatitis may result from a disruption of normal stimulus-secretion coupling within the acinar cell. Future research based on these observations may ultimately result in successful therapy for this disease.

Treatment of acute pancreatitis. Comparison of animal and human studies

In this review, we compared the outcome of 25 studies of experimentally induced pancreatitis in animals with 13 studies of human acute pancreatitis in which the same therapeutic agents were used (aprotinin, glucagon, 5-fluorouracil, somatostatin, peritoneal lavage). Whereas 81% of the animal studies had a positive outcome (improvement in survival), only 7.7% of the human studies showed a positive outcome on survival. Most animal studies suffered from a protocol in which treatment was not significantly delayed after induction of acute pancreatitis. Of the 12 human studies that showed no effect of treatment on survival, none had sufficient statistical power (1 - beta error) for the investigators to have confidence in the negative outcomes. This was due to the fact that the studies had too few patients or that the event rates in the untreated populations were too low. Only five of the human studies reported the complication rates of acute pancreatitis in patients who did not die of their disease. Treatment (by any agent) did not improve the complication rate in these studies, but only one of the five reports had sufficient statistical power for the investigators to have confidence in these negative results. Large multicenter studies with sufficient numbers of patients with severe pancreatitis (high mortality and complication rates) are needed to evaluate new therapies in this disease.

Effects of somatostatin on acute canine experimental pancreatitis

Somatostatin is an inhibitory hormone that decreases the secretion and end organ response of cholecystokinin (CCK). Inhibition of hormonal stimulation of pancreatic exocrine secretion by somatostatin may improve the course of acute pancreatitis. Anesthetized dogs underwent cholecystectomy and cannulation of the pancreatic duct, thoracic duct, and portal vein. Twenty experiments were performed in random order with 5 dogs in each group. Hourly measurements of lymph flow and portal and thoracic duct amylase were made. Portal blood insulin, glucagon, and CCK concentrations were determined by radioimmunoassay on samples obtained at the beginning and end of the experiments. Pancreatitis was induced by injecting, under constant pressure, 10 ml bile into the pancreatic duct during 1 min. Somatostatin was administered intravenously (20 micrograms/kg/hr). After 5 h, the dogs were killed, pancreas glands removed and weighed and tissue samples obtained for histologic evaluation. There was a significant increase in lymph amylase output and portal venous amylase and CCK concentrations in the dogs with pancreatitis compared to the control dogs. In dogs with pancreatitis, lymphatic amylase secretion and portal CCK concentrations were significantly decreased by somatostatin. Somatostatin did not significantly alter portal amylase concentrations, pancreas gland weights or histologic inflammation when compared to values from dogs with pancreatitis not treated with somatostatin.

Acute and chronic pancreatitis. An update on management

Therapeutic measures for acute pancreatitis depend on the severity of the disease and its complications. Since complications of acute pancreatitis may develop at any time, patients should be admitted to an intensive care unit for assessment (and frequent reassessment) of the severity of the disease and the development of complications. Basic therapy should include relief of pain, total fasting, nasogastric suction, parenteral replacement of fluids, electrolytes, albumin and blood, and antibiotics. Hyperglycaemia should be corrected and heparin should be given in cases of disseminated intravascular coagulation. In renal insufficiency, peritoneal dialysis is important, and in respiratory complications, humidified oxygen or artificial ventilation including positive and expiratory pressure therapy should be applied. Although the effect of peritoneal dialysis has been proven only in animal experiments and in retrospective studies in man, it is recommended in severe cases for shock therapy and for correction of electrolyte imbalance when ascites is present, even before anuria occurs. Conservative treatment measures in chronic pancreatitis are limited to the management of pain and of exocrine and endocrine pancreatic insufficiency.

Calcitonin: analgesic effects

Animal experiments demonstrate that the intracerebro-ventricular administration of calcitonin induces analgesia. During the treatment of such diseases as osteitis deformans Paget and acute pancreatitis with calcitonin no spectacular pain-relieving effect was evident, but the application of calcitonin in hypercalcemic patients with bone tumors led to considerable pain relief. Recent double-blind studies document the analgesic effectiveness of calcitonin in malignant diseases, but also against postoperative pains in nontumor patients. Calcitonin as an analgesic drug deserves further investigation.

Beneficial effect of pancreatic polypeptide in experimental pancreatitis

Two animal models have been employed to examine the role of pancreatic polypeptide, a potent and selective inhibitor of pancreatic exocrine secretion, in the treatment of acute pancreatitis. In one model pancreatitis was induced by feeding young female Swiss Webster mice an ethionine-supplemented, choline-deficient diet for 48 hr. Animals (N = 30 per group) were injected subcutaneously every 8 hr for 7 days with pancreatic polypeptide (0, 2, 20, and 200 micrograms/kg/day). Treatment with 20 and 200 micrograms/kg/day pancreatic polypeptide significantly (P less than 0.05) reduced mortality from a control rate of 70% to 42% and 33%, respectively. Treated animals also exhibited significant (P less than 0.05) decreases in pancreatic content of activated chymotrypsin and an improvement in pancreatic histology. Pancreatic polypeptide was effective whether treatment was started before or at the same time the test diet was introduced. In contrast, pancreatic polypeptide failed to protect dogs with acute pancreatitis induced by retrograde injection of the pancreas with bile, which may reflect the rapid and mechanical nature of pancreatic damage in this animal model.

Antiproteinase chemotherapy of acute experimental pancreatitis using the low molecular weight oligopeptide aldehyde leupeptin

Continuous intravenous infusion of the low molecular weight trypsin inhibitor leupeptin prolonged the survival of rats with acute haemorrhagic pancreatitis (p less than 0.001) compared with controls receiving saline alone. Rats receiving high dose intravenous Trasylol (aprotinin) survived no longer than saline-only controls. Combination therapy of leupeptin with Trasylol conferred no additional benefit over animals treated with leupeptin alone. The nature of the infusion was selected blind after the induction of pancreatitis and survival was quantified by recording of body temperature. These preliminary results suggest that sterically favourable molecules which can complete the inhibiton of alpha 2-macroglobulin bound proteinases should contribute to the effective specific chemotherapy of the disease.

Similar modes of action of calcitonin and glucagon in inhibiting pancreatic enzyme secretion in man

The inhibitory action of both calcitonin (CT) and glucagon (GK) on human pancreatic secretion has been evaluated in detail. The reduction of enzyme secretion expressed as percentage corresponded to 60--80% of the initial values in response to both CT and GK when the hormones were given as single infusions during background stimulation with secretin or with secretin plus cholecystokinin-pancreozymin (CCK-PZ). After withdrawal of GK-infusion the return to normal values of enzyme secretion was distinctly faster than after CT, thus reflecting a more rapid degradation of circulating GK than of CT. In the presence of stimulation with secretin plus CCK-PZ, the combined administration of CT and GK did not enhance the inhibitory actions of CT and GK. Fluid and bicarbonate secretions were not affected by either CT or GK. The results suggest that CT and GK inhibit human pancreatic enzyme secretion by similar modes of action. Therefore, the combined administration of both CT and GK does not offer a reasonable approach to the treatment of acute pancreatitis.