The effects of somatostatin and octreotide on experimental and human acute pancreatitis

Relationship between somatostatin and interleukin-6: A cross-sectional study in patients with acute pancreatitis

OBJECTIVES

The aim of the analysis is to determine dynamic changes in somatostatin (SS) and interleukin-6 (IL-6) concentrations during in acute pancreatitis (AP).

METHODS

The influence of tobacco smoking on IL-6 and SS levels in the serum of non-smoking (n = 10) and smoking (n = 27) patients with diagnosed AP and control group: non-smoking (n = 44), smoking (n = 42) and passive smoking (n = 29) healthy persons was proved. The concentration of IL-6 and SS was determined by means of ELISA. Differences between the groups analyzed were tested using the U Mann Whitney test. The Spearman rank correlation analysis was used to evaluate the correlations.

RESULTS

The concentrations of IL-6 and SS were significantly higher in smoking patients with AP and healthy persons when compared with non-smoking population on every day (1 day: p = 0.0002, p = 0.015; 3 day: p = 0.005, p = 0.001 and 7 day: p = 0.025, p = 0.038). Dynamic changes in concentrations of IL-6 and SS in the serum of patients with AP were demonstrated in the ensuing days of the disease. In case of non-smoking and smoking patients, significant positive correlations between IL-6 and SS was observed.

CONCLUSIONS

These findings suggest that some of the antiinflammatory effects of SS against acute pancreatitis may be mediated by reducing the local proinflammatory cytokine secretion in the pancreas.

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.

Acute pancreatitis in children and adolescents

In this Topic Highlight, the causes, diagnosis, and treatment of acute pancreatitis in children are discussed. Acute pancreatitis should be considered during the differential diagnosis of abdominal pain in children and requires prompt treatment because it may become life-threatening. The etiology, clinical manifestations, and course of acute pancreatitis in children are often different than in adults. Therefore, the specific features of acute pancreatitis in children must be considered. The etiology of acute pancreatitis in children is often drugs, infections, trauma, or anatomic abnormalities. Diagnosis is based on clinical symptoms (such as abdominal pain and vomiting), serum pancreatic enzyme levels, and imaging studies. Several scoring systems have been proposed for the assessment of severity, which is useful for selecting treatments and predicting prognosis. The basic pathogenesis of acute pancreatitis does not greatly differ between adults and children, and the treatments for adults and children are similar. In large part, our understanding of the pathology, optimal treatment, assessment of severity, and outcome of acute pancreatitis in children is taken from the adult literature. However, we often find that the common management of adult pancreatitis is difficult to apply to children. With advances in diagnostic techniques and treatment methods, severe acute pancreatitis in children is becoming better understood and more controllable.

Prevention of severe acute pancreatitis with octreotide in obese patients: a prospective multi-center randomized controlled trial

OBJECTIVES

To evaluate the efficacy of octreotide in preventing severe acute pancreatitis (SAP) in obese patients.

METHODS

A prospective multi-center partly randomized control trial was conducted in patients with mild acute pancreatitis (AP). Nonobese patients received conventional management (nonobese-C, n = 82), whereas obese patients (body mass index ≥ 25 kg/m(2)) were randomized into 2 groups: obese-C (n = 79), who received conventional management, and obese-C+O (n = 82), who received conventional management plus intravenous infusion of octreotide, 50 μg/h for 72 hours.

RESULTS

The risk ratio and relative risk reduction in the development of SAP in the obese-C+O group were 0.27 (95% confidence interval, 0.10-0.69) and 0.73 (95% confidence interval, 0.31-0.90), respectively. The number of cases developing local complications in the obese-C+O group was significantly smaller than that in the obese-C group: 4.9% vs 19%, P = 0.006. The plasma level of somatostatin in the obese-C+O group was significantly higher than that in the obese-C group: 165.5 ± 42.6 vs 112.1 ± 24.86 pg/mL, P < 0.05. Supplement of octreotide also accompanied with reduction in plasma levels of tumor necrosis factor α and IL-6.

CONCLUSIONS

Intravenous administration of octreotide (50 μg/h) for 72 hours in the early stage of AP could prevent the development of SAP effectively in obese patients by raising plasma somatostatin to a normal level and reducing circulating cytokines.

Targeting the metabolic microenvironment of tumors

The observation of aerobic glycolysis by tumor cells in 1924 by Otto Warburg, and subsequent innovation of imaging glucose uptake by tumors in patients with PET-CT, has incited a renewed interest in the altered metabolism of tumors. As tumors grow in situ, a fraction of it is further away from their blood supply, leading to decreased oxygen concentrations (hypoxia), which induces the hypoxia response pathways of HIF1α, mTOR, and UPR. In normal tissues, these responses mitigate hypoxic stress and induce neoangiogenesis. In tumors, these pathways are dysregulated and lead to decreased perfusion and exacerbation of hypoxia as a result of immature and chaotic blood vessels. Hypoxia selects for a glycolytic phenotype and resultant acidification of the tumor microenvironment, facilitated by upregulation of proton transporters. Acidification selects for enhanced metastatic potential and reduced drug efficacy through ion trapping. In this review, we provide a comprehensive summary of preclinical and clinical drugs under development for targeting aerobic glycolysis, acidosis, hypoxia and hypoxia response pathways. Hypoxia and acidosis can be manipulated, providing further therapeutic benefit for cancers that feature these common phenotypes.

Therapeutic applications of octreotide in pediatric patients

BACKGROUND/AIM

We report our experience with the use of octreotide as primary or adjunctive therapy in children with various gastrointestinal disorders.

PATIENTS AND METHODS

A pharmacy database identified patients who received octreotide for gastrointestinal diseases. Indications for octreotide use, dosing, effectiveness, and adverse events were evaluated by chart review.

RESULTS

A total of 21 patients (12 males), aged 1 month to 13 years, were evaluated. Eleven received octreotide for massive gastrointestinal bleeding caused by portal hypertension-induced lesions (n=7), typhlitis (1), Meckel's diverticulum (1), and indefinite source (2). Blood transfusion requirements were reduced from 23 ± 9 mL/kg (mean ± SD) to 8 ± 15 mL/kg (P<0.01). Four patients with pancreatic pseudocyst and/or ascites received octreotide over 14.0 ± 5.7 days in 2 patients. In 3 children, pancreatic pseudocyst resolved in 12 ± 2 days and pancreatic ascites resolved in 7 days in 2. Three patients with chylothorax received octreotide for 14 ± 7 days with complete resolution in each. Two infants with chronic diarrhea received octreotide over 11 ± 4.2 months. Stool output decreased from 85 ± 21 mL/kg/day to 28 ± 18 mL/kg/day, 3 months after initiation of octreotide. The child with dumping syndrome responded to octreotide in a week. Adverse events developed in 4 patients: Q-T interval prolongation and ventricular fibrillation, hyperglycemia, growth hormone deficiency, and hypertension.

CONCLUSION

Octreotide provides a valuable addition to the therapeutic armamentum of the pediatric gastroenterologist for a wide variety of disorders. Serious adverse events may occur and patients must be closely monitored.

Octreotide ameliorates intestinal dysmotility by interstitial cells of Cajal protection in a rat acute necrotizing pancreatitis model

OBJECTIVES

Intestinal motility is impaired in acute necrotizing pancreatitis (ANP). The aim of present study was to investigate the effects of octreotide on the small intestinal motor function during experimentally induced ANP.

METHODS

L-Ornithine was intraperitoneally injected to induce ANP. Octreotide was administrated subcutaneously every 8 hours. The small intestine migrating myoelectrical complexes and slow waves in vivo were recorded before and after (24, 48, and 72 hours) ANP induction. The morphological alterations of interstitial cells of Cajal (ICCs) in deep muscular plexus were evaluated by immunohistochemistry and Western blots.

RESULTS

Disturbed migrating myoelectrical complex cycle length and decreased dominant frequency of slow waves exacerbated gradually with time. The bolus applications of octreotide per 8 hours attenuated these functional abnormalities. The result of morphological study suggested that octreotide might ameliorate the damage of ICCs at 48 and 72 hours after ANP induction. Decreased expression of c-Kit protein at 72 hours was also attenuated by octreotide.

CONCLUSIONS

The pathogenesis of the ileus in ANP may be related to the sustained deficiencies in ICCs. Octreotide may ameliorate the severity of ileus by minimizing the injury of ICCs.

[The clinical relevance of experimental acute pancreatitis models]

The clinical diagnostics and therapeutic standards applied in the routine management of human acute pancreatitis are based on the results of animal experiments and human studies performed in the past several decades. During this time period, a number of experimental acute pancreatitis models have been developed, which allowed us to study the etiopathogenesis of acute pancreatitis, analyzing the local and remote complications of the inflammatory processes and also the preclinical testing of potentially effective drugs and agents. Only animal models are suitable to examine the very early phase of the pathogenetic processes in acute pancreatitis. In recent years, the progress in molecular genetic methods allowed us to create genetically engineered animal models to clarify the role of different mediators in the pathogenetic process. There is no doubt that the results gained from experimental animal studies are of limited value concerning human pancreatitis. Nevertheless, experimental studies seem to be indispensable in the progress of management of human pancreatic disorders.

TT232, A Novel Signal Transduction Inhibitory Compound in the Therapy of Cancer and Inflammatory Diseases

TT-232 is a structural analogue of somatostatin exhibiting strong and selective growth-inhibitory effects, inhibition of neurogenic inflammation, as well as general anti-inflammatory and analgesic potential without the wide-ranging endocrine side effects of the parent hormone and its "traditional" analogues. The anti-inflammatory action of TT-232 is mediated through the SSTR4 receptor, and its antitumor activity is mediated through the SSTR1 receptor and by the tumor-specific isoform of pyruvate kinase. Its mechanism of action is in line with a new era of molecular medicine called signal transduction therapy, where "false" intracellular or intercellular communication is inhibited or corrected without interfering with basic cell functions and machinery. TT232 has passed phase I clinical trials without toxicity and significant side effects, and phase II studies are running for oncological and anti-inflammatory indications, respectively. This compound has the perspective to become the first drug in molecularly targeted therapy of inflammation where a combined effect of anti-inflammatory, analgesic, and neurogenic inflammation-inhibiting activity can be achieved.

Octreotide prevents L-asparaginase-induced pancreatic injury in rats

OBJECTIVE

L-asparaginase (ASNase) is one of the most effective chemotherapeutic means for inducing remission in acute lymphoblastic leukemia. However, because of unknown risk factors, severe pancreatitis sometimes occurs in patients receiving ASNase. We assessed the effect of ASNase on pancreatic acinar cells and then investigated the preventive effects of octreotide against ASNase-induced pancreatic injury in rats.

MATERIALS AND METHODS

Rats received intraperitoneal injections of an Escherichia coli ASNase solution (200, 500, or 1000 IU/kg) or normal saline as a control every 24 hours for 5 days. Octreotide (3 microg/kg) was injected subcutaneously with ASNase (1000 IU/kg) every 8 hours for 5 days. Rats were sacrificed 24 hours after the last injection of ASNase or normal saline.

RESULTS

Only the rats given 1000 IU/kg ASNase had significantly increased levels of pancreatic amylase (1962 +/- 152 vs 2179 +/- 84 IU/L, p < 0.01), trypsin (27.3 +/- 3.6 vs 41.1 +/- 22.8 IU/L, p < 0.05), and pancreatic secretory trypsin inhibitor (0.03 +/- 0.09 vs 0.27 +/- 0.10 ng/mL, p < 0.01) as compared to the control group. In addition, the acinar cells showed histological damage; however, octreotide injection provided protection against histological damage and the pancreatic enzymes remained within normal limits.

CONCLUSIONS

Although ASNase by itself did not cause pancreatitis, it did cause increased levels of pancreatic enzymes and histological damage to the pancreas associated with pancreatic injury or pre-pancreatitis. Prior treatment with octreotide prevented the development of ASNase-induced pancreatic injury.

Current pharmacotherapeutic recommendations for acute pancreatitis

Disease severity in patients with acute pancreatitis varies from mild disease with minimal morbidity to severe disease in which a whole spectrum of local and systemic complications may occur. Infectious complications frequently arise, and pancreatic necrosis in particular is an important risk factor for mortality. Several strategies have been investigated to stop the progression of organ dysfunction, targeting different steps in the pathogenesis, but none of these have proved beneficial. In recent years, the widespread use of prophylactic antibiotics has also been in question, as one blinded study could not demonstrate an advantage. Better risk stratification methods should improve the design of future trials, so that only patients with a high probability of complications can be studied.

Octreotide hardens the pancreas

BACKGROUND AND AIMS

Leakage from pancreaticojejunostomy and development of pancreatic fistulas are the major postoperative complications in patients undergoing duodenopancreatectomy. The risk of developing these complications is higher when surgery is performed on a soft pancreas. A recent report suggests that octreotide hardens the pancreas when given intraoperatively. The present study aims at verifying this observation by measuring tissue hardness of the pancreas by a commercially available durometer in pigs with and without octreotide pretreatment.

METHODS

Three groups of pigs were investigated: Group 1 (n=6) received no treatment; group 2 (n=6) was treated with 3x100 microg octreotide for 1 day; group 3 (n=6) for 5 days. Thereafter, animals were killed and the pancreas was harvested for performing measurements: Tissue hardness was assessed by a commercially available durometer, and a suture holding test was performed using a Newton dynamometer.

RESULTS

There was a significant increase in tissue hardness between untreated control animals [26.3+/-2.5 S.U. (shore units)] and animals with 1 day octreotide pretreatment (29.8+/-2.6 S.U.; p=0.04) as well as between the groups treated for 1 and 5 days (34.8+/-2.8 S.U.; p=0.01). Suture holding capacity was higher in animals treated for 5 days.

CONCLUSION

The present study agrees with a recent report suggesting that octreotide hardens the pancreas. Octreotide pretreatment may therefore be an advantage when performing surgery on a soft pancreas, i.e., in patients scheduled for duodenopancreatectomy for ampullary carcinomas or circumscript pancreatic tumors not associated with chronic pancreatitis.

Effects of octreotide on acute necrotizing pancreatitis in rabbits

AIM: To assess the role of oxygen-derived free radicals and cytokines in the pathogenesis of taurocholic acid-induced acute pancreatitis, and to evaluate the preventive effects of octreotide towards the development of acute pancreatitis.

METHODS: Acute pancreatitis was induced in male New Zealand white rabbits by retrograde injection of 0.8 mL/kg·b.m. of 50 g/L sodium taurocholate (NaTC) in the pancreatic duct. Sham-operated animals served as control. Octreotide 1 mg/kg·b.m. was administered subcutaneously before the induction of pancreatitis. Blood was taken from the jugular vein before and at 1, 3, 6, 12 and 24 h after pancreatitis induction. Serum activities of amylase, IL-6 and TNF-α and levels of malonyl dialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), catalase and superoxide dismutase (Mn-, Cu-, and Zn-SOD) in pancreatic tissue were measured.

RESULTS: Serum TNF-α and IL-6 levels increased significantly 3 h after the onset of pancreatitis, and then returned to control level. The tissue concentration of MDA was significantly elevated at 24 h, while the GSH level and GPx, catalase, Mn-SOD, Cu-, Zn-SOD activities were all significantly decreased in animals with pancreatitis as compared to the control. Octreotide pretreatment significantly reversed the changes in cytokines and reactive oxygen metabolites. Octreotide treatment did not alter the serum amylase activity and did not have any beneficial effects on the development of histopathological changes.

CONCLUSION: Oxygen-derived free radicals and proinflammatory cytokines are generated at an early stage of NaTc-induced acute pancreatitis in rabbits. Prophylactic octreotide treatment can prevent release of cytokines and generation of reactive oxygen metabolites, but does not have any beneficial effects on the development of necrotizing pancreatitis.

Effects of octreotide pretreatment in experimental acute pancreatitis

BACKGROUND

Severity of systemic lesions and mortality of experimental acute pancreatitis (AP) are reduced after pancreatic enzyme content reduction induced by cerulein administration. Octreotide has been used both prophylatically and therapeutically in AP. The possible effects of octreotide on pancreatic enzyme content and its influence on pulmonary lesions of experimental AP were assessed in this study.

METHODS

Wistar male rats were divided in two branches: BRANCH I - Animals divided into three groups: Group Sa (n = 10) intravenous saline infusion; Group Ce (n = 10) intravenous cerulein infusion, (0.133 micro g/kg(-1).h(-1)) and Group Oc (n = 10) SC octreotide (10 micro g/kg(-1)). Trypsin, elastase and amylase pancreatic contents as well as serum amylase were determined thereafter in all three groups; BRANCH II - Rats treated as in branch I, were submitted to sodium taurocholate AP (Groups Sa+AP, Ce+AP and Oc+AP). Two hours thereafter amylase and TAP assays were performed in serum, ascites and pancreatic tissue in eight animals of each group. Pulmonary histology was studied by morphometry 24 h after AP in the remaining animals.

RESULTS

Increased serum amylase and pancreatic enzyme contents were observed in octreotide-treated animals when compared to animals receiving saline or cerulein. After AP increases of serum and ascitic fluid amylase and of pancreatic TAP were observed in octreotide pre-treated animals when compared to saline and cerulein groups. Pulmonary interstitial and alveolar edema after AP was significantly increased in rats receiving octreotide as compared to the cerulein group.

CONCLUSION

Octreotide administration acutely increases the enzymatic content of the pancreas and thus may have a potential deleterious influence in the evolution of AP.