A pleiotropy scan to discover new susceptibility loci for pancreatic ductal adenocarcinoma.

Pleiotropic variants (i.e., genetic polymorphisms influencing more than one phenotype) are often associated with cancer risk. A scan of pleiotropic variants was successfully conducted ten years ago in relation to pancreatic ductal adenocarcinoma susceptibility. However, in the last decade, genetic association studies performed on several human traits have greatly increased the number of known pleiotropic variants. Based on the hypothesis that variants already associated with a least one trait have a higher probability of association with other traits, 61,052 variants reported to be associated by at least one genome wide association study (GWAS) with at least one human trait were tested in the present study consisting of two phases (discovery and validation), comprising a total of 16,055 pancreatic ductal adenocarcinoma (PDAC) cases and 212,149 controls. The meta-analysis of the two phases showed two loci (10q21.1-rs4948550 (P=6.52×10-5) and 7q36.3-rs288762 (P=3.03×10-5) potentially associated with PDAC risk. 10q21.1-rs4948550 shows a high degree of pleiotropy and it is also associated with colorectal cancer risk while 7q36.3-rs288762 is situated 28,558 base pairs upstream of the Sonic Hedgehog (SHH) gene, which is involved in the cell differentiation process and PDAC etiopathogenesis. In conclusion, none of the single nucleotide polymorphisms (SNPs) showed a formally statistically significant association after correction for multiple testing. However, given their pleiotropic nature and association with various human traits including colorectal cancer, the two SNPs showing the best associations with PDAC risk merit further investigation through fine mapping and ad hoc functional studies.

Reducing cardiovascular risk in immune-mediated inflammatory diseases: Tumour necrosis factor inhibitors compared to conventional therapies-A systematic review and meta-analysis.

Immune-mediated inflammatory disease (IMID) patients including psoriasis, inflammatory arthritides and bowel diseases have a higher risk of developing cardiovascular (CV) diseases compared to the general population. The increased CV risk may be promoted by tumour necrosis factor (TNF)-α-mediated immunological processes, which are present both in the pathomechanism of IMIDs and atherosclerosis. Our objective was to comprehensively investigate the effect of TNF inhibitors (TNFi) on CV risk compared with conventional therapies in IMIDs. The systematic literature search was conducted in three databases (MEDLINE, EMBASE, Cochrane Library) on 14 November 2022. Randomized controlled trials, cohort and case-control studies were eligible for inclusion. Outcomes consisted of the incidence of CV events, with major adverse cardiovascular events (MACE) as a main endpoint. A random-effects meta-analysis was performed by pooling fully adjusted multivariate hazard ratios (HR) and incidence rate ratios (IRR) with a 95% confidence interval (CI) comparing TNFis with conventional systemic non-biologicals (CSNBs). Of a total of 8724 search results, 56 studies were included overall, of which 29 articles were eligible for the meta-analysis, and 27 were involved in the systematic review. Including all IMIDs, the TNFi group showed a significantly reduced risk of MACE compared with the CSNB group (HR = 0.74, 95% confidence interval (CI) 0.58-0.95, p = 0.025; IRR = 0.77, 95% CI 0.67-0.88, p < 0.001). Subgroup analysis of Pso, PsA patients by pooling IRRs also confirmed the significantly decreased risk of MACE in TNFi-treated patients compared with CSNB groups (IRR = 0.79, 95% CI 0.64-0.98). The observational nature of most included studies leading to high heterogeneity represents a limitation. Based on the results, TNFis may reduce the risk of CV events compared to CSNBs. Therefore, earlier use of TNFis compared to conventional systemic agents in the therapeutic sequence may benefit CV risk in IMID patients.

Acupuncture increases parasympathetic tone, modulating HRV - Systematic review and meta-analysis.

INTRODUCTION: An increasing number of studies have demonstrated that acupuncture can influence Autonomic Nervous System functions. Heart Rate variability (HRV) is one widely used marker of autonomic activity. The main objective of this systematic review is to critically assess the evidence from randomized clinical trials (RCTs) regarding the effect of acupuncture on HRV as compared to placebo methods. METHOD: EMBASE, Pubmed, The Cochrane Library, Web of Science, Scopus electronic databases were searched until 9 September 2020 for RCTs in which human subjects were treated with needle acupuncture using acupoints of the body without electric stimulation. RESULTS: The searches identified 1698 potentially relevant articles, 9 RCTs were included. The statistical analysis of the available data showed that the changes between pre and post treatment HF (high frequency) and LF/HF (high frequency/low frequency) values in Verum group were significant, while there were no significant changes in these parameters in Sham groups. CONCLUSION: the results of this meta-analysis suggest that real acupuncture has superior effect over placebo acupuncture in increasing parasympathetic tone and in this way may improve physical well-being. Due to the quality of primary studies and degree of heterogeneity the results should be interpreted cautiously.

MIF is a common genetic determinant of COVID-19 symptomatic infection and severity.

BACKGROUND: Genetic predisposition to coronavirus disease 2019 (COVID-19) may contribute to its morbidity and mortality. Because cytokines play an important role in multiple phases of infection, we examined whether commonly occurring, functional polymorphisms in macrophage migration inhibitory factor (MIF) are associated with COVID-19 infection or disease severity. AIM: To determine associations of common functional polymorphisms in MIF with symptomatic COVID-19 or its severity. METHODS: This retrospective case-control study utilized 1171 patients with COVID-19 from three tertiary medical centers in the USA, Hungary and Spain, together with a group of 637 pre-pandemic, healthy control subjects. Functional MIF promoter alleles (-794 CATT5-8,rs5844572), serum MIF and soluble MIF receptor levels, and available clinical characteristics were measured and correlated with COVID-19 diagnosis and hospitalization. Experimental mice genetically engineered to express human high- or low-expression MIF alleles were studied for response to coronavirus infection. RESULTS: In patients with COVID-19, there was a lower frequency of the high-expression MIF CATT7 allele when compared to healthy controls [11% vs. 19%, odds ratio (OR) 0.54 [0.41-0.72], P < 0.0001]. Among inpatients with COVID-19 (n = 805), there was a higher frequency of the MIF CATT7 allele compared to outpatients (n = 187) (12% vs. 5%, OR 2.87 [1.42-5.78], P = 0.002). Inpatients presented with higher serum MIF levels when compared to outpatients or uninfected healthy controls (87 ng/ml vs. 35 ng/ml vs. 29 ng/ml, P < 0.001, respectively). Among inpatients, circulating MIF concentrations correlated with admission ferritin (r = 0.19, P = 0.01) and maximum CRP (r = 0.16, P = 0.03) levels. Mice with a human high-expression MIF allele showed more severe disease than those with a low-expression MIF allele. CONCLUSIONS: In this multinational retrospective study of 1171 subjects with COVID-19, the commonly occurring -794 CATT7MIF allele is associated with reduced susceptibility to symptomatic SARS-CoV-2 infection but increased disease progression as assessed by hospitalization. These findings affirm the importance of the high-expression CATT7MIF allele, which occurs in 19% of the population, in different stages of COVID-19 infection.

Prevalence of other autoimmune diseases in polyglandular autoimmune syndromes type II and III.

PURPOSE: Polyglandular autoimmune syndromes (PAS) are complex, heterogeneous disorders in which various autoimmune diseases can occur, affecting both endocrine and non-endocrine organs. In this meta-analysis, the prevalence of associated autoimmune disorders was investigated in PAS II and III. METHODS: A comprehensive search in MEDLINE and Embase databases identified 479 studies with the keywords of PAS II and PAS III. 18 records containing a total of 1312 patients fulfilled our inclusion criteria (original studies reporting at least 10 cases and containing the combination of other autoimmune disorders) and were selected for further analysis. A meta-analysis of prevalence was performed using the random-effects model with the calculation of 95% confidence intervals (CI). Results of each meta-analysis were displayed graphically using forest plots. RESULTS: Distinction between PAS II and PAS III was made in 842 cases, of which 177 and 665 were PAS II and III (21.1 vs 78.9%), respectively. The prevalence of Hashimoto's thyroiditis was significantly higher than that of Graves's disease (39% [95% CI 17-65%] vs. 4% [95% CI 0-10%], respectively; p = 0.001). In PAS II, Addison's disease (AD) coexisted with AITDs, T1DM or the combination of these conditions in 65, 18 and 10% of cases, respectively. In addition, one other endocrine and five non-endocrine organ-specific autoimmune disorders were reported. In PAS III, two other autoimmune endocrinopathies, six non-endocrine organ-specific, and four systemic autoimmune disorders were found in combination with AITDs. CONCLUSIONS: AITDs, T1DM and AD are the most common combinations in PAS, thus screening for these conditions seems to be reasonable.

Germline BRCA2 K3326X and CHEK2 I157T mutations increase risk for sporadic pancreatic ductal adenocarcinoma.

Rare truncating BRCA2 K3326X (rs11571833) and pathogenic CHEK2 I157T (rs17879961) variants have previously been implicated in familial pancreatic ductal adenocarcinoma (PDAC), but not in sporadic cases. The effect of both mutations in important DNA repair genes on sporadic PDAC risk may shed light on the genetic architecture of this disease. Both mutations were genotyped in germline DNA from 2,935 sporadic PDAC cases and 5,626 control subjects within the PANcreatic Disease ReseArch (PANDoRA) consortium. Risk estimates were evaluated using multivariate unconditional logistic regression with adjustment for possible confounders such as sex, age and country of origin. Statistical analyses were two-sided with p values <0.05 considered significant. K3326X and I157T were associated with increased risk of developing sporadic PDAC (odds ratio (ORdom ) = 1.78, 95% confidence interval (CI) = 1.26-2.52, p = 1.19 × 10-3 and ORdom = 1.74, 95% CI = 1.15-2.63, p = 8.57 × 10-3 , respectively). Neither mutation was significantly associated with risk of developing early-onset PDAC. This retrospective study demonstrates novel risk estimates of K3326X and I157T in sporadic PDAC which suggest that upon validation and in combination with other established genetic and non-genetic risk factors, these mutations may be used to improve pancreatic cancer risk assessment in European populations. Identification of carriers of these risk alleles as high-risk groups may also facilitate screening or prevention strategies for such individuals, regardless of family history.

Efficacy and Safety of FOLFIRINOX in Locally Advanced Pancreatic Cancer. A Single Center Experience.

The management of locally advanced pancreatic cancer (LAPC) is a major challenge. Although new drugs are available for the treatment of metastatic disease, the optimal treatment of non-metastatic cases remains controversial. The role of neoadjuvant therapy is still a question of debate in this setting. The aim of the study was to prospectively collect and analyse data on efficacy and safety of a modified FOLFIRINOX regimen in LAPC patients treated in a single institution. Another major objective was to assess the capability of FOLFIRINOX to render primary non-resectable cancer to resectable. No bolus fluorouracil was given and a 20% dose reduction of oxaliplatin and irinotecan was applied. Primary G-CSF prophylaxis was applied to prevent febrile neutropenia. Thirty-two patients (mean age 60.2 years, range: 40-77 years) have been enrolled into the study. All patients had ECOG performance status of 0 or 1. Best response to therapy was stable disease (SD) or partial regression (PR) in 18 (56.2%) and 6 (18.8%) cases. Two patients (6.3%) underwent surgical resection (100% R0). The most frequent grade 3/4 adverse events were nausea (18.8%), fatigue (12.5%) and diarrhea (12.5%). The incidence of severe neutropenia was 28.1%, with only one documented case of febrile neutropenia. The probability of disease progression was 25% and 50% after 75 and 160 days with 88.4% of possibility of disease progression after 500 days. OS probability was 92.1, 71.5% and 49.5% at 180-, 365 and 540 days. Our data does not support the capability of FOLFIRINOX to render primary non-resectable cancer to resectable. However, due to the high disease control rate observed, FOLFRINOX might be recommended as first line option for the palliative treatment of LAPC. Despite reduced chemotherapy doses significant toxicity has been seen.

Bile acids inhibit Na⁺/H⁺ exchanger and Cl⁻/HCO3⁻ exchanger activities via cellular energy breakdown and Ca²âº overload in human colonic crypts.

Bile acids play important physiological role in the solubilisation and absorption of dietary lipids. However, under pathophysiological conditions, such as short bowel syndrome, they can reach the colon in high concentrations inducing diarrhoea. In this study, our aim was to characterise the cellular pathomechanism of bile-induced diarrhoea using human samples. Colonic crypts were isolated from biopsies of patients (controls with negative colonoscopic findings) and of cholecystectomised/ileum-resected patients with or without diarrhoea. In vitro measurement of the transporter activities revealed impaired Na⁺/H⁺ exchanger (NHE) and Cl⁻/HCO3⁻ exchanger (CBE) activities in cholecystectomised/ileum-resected patients suffering from diarrhoea, compared to control patients. Acute treatment of colonic crypts with 0.3 mM chenodeoxycholate caused dose-dependent intracellular acidosis; moreover, the activities of acid/base transporters (NHE and CBE) were strongly impaired. This concentration of chenodeoxycholate did not cause morphological changes in colonic epithelial cells, although significantly reduced the intracellular ATP level, decreased mitochondrial transmembrane potential and caused sustained intracellular Ca²âº elevation. We also showed that chenodeoxycholate induced Ca²âº release from the endoplasmic reticulum and extracellular Ca²âº influx contributing to the Ca²âº elevation. Importantly, our results suggest that the chenodeoxycholate-induced inhibition of NHE activities was ATP-dependent, whereas the inhibition of CBE activity was mediated by the sustained Ca²âº elevation. We suggest that bile acids inhibit the function of ion transporters via cellular energy breakdown and Ca²âº overload in human colonic epithelial cells, which can reduce fluid and electrolyte absorption in the colon and promote the development of diarrhea.

Ethanol and its non-oxidative metabolites profoundly inhibit CFTR function in pancreatic epithelial cells which is prevented by ATP supplementation.

Excessive alcohol consumption is a major cause of acute pancreatitis, but the mechanism involved is not well understood. Recent investigations suggest that pancreatic ductal epithelial cells (PDECs) help defend the pancreas from noxious agents such as alcohol. Because the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel plays a major role in PDEC physiology and mutated CFTR is often associated with pancreatitis, we tested the hypothesis that ethanol affects CFTR to impair ductal function. Electrophysiological studies on native PDECs showed that ethanol (10 and 100 mM) increased basal, but reversibly blocked, forskolin-stimulated CFTR currents. The inhibitory effect of ethanol was mimicked by its non-oxidative metabolites, palmitoleic acid ethyl ester (POAEE) and palmitoleic acid (POA), but not by the oxidative metabolite, acetaldehyde. Ethanol, POAEE and POA markedly reduced intracellular ATP (ATPi) which was linked to CFTR inhibition since the inhibitory effects were almost completely abolished if ATPi depletion was prevented. We propose that ethanol causes functional damage of CFTR through an ATPi-dependent mechanism, which compromises ductal fluid secretion and likely contributes to the pathogenesis of acute pancreatitis. We suggest that the maintenance of ATPi may represent a therapeutic option in the treatment of the disease.

Central role of mitochondrial injury in the pathogenesis of acute pancreatitis.

Acute pancreatitis is an inflammatory disease with no specific treatment. One of the main reasons behind the lack of specific therapy is that the pathogenesis of acute pancreatitis is poorly understood. During the development of acute pancreatitis, the disease-inducing factors can damage both cell types of the exocrine pancreas, namely the acinar and ductal cells. Because damage of either of the cell types can contribute to the inflammation, it is crucial to find common intracellular mechanisms that can be targeted by pharmacological therapies. Despite the many differences, recent studies revealed that the most common factors that induce pancreatitis cause mitochondrial damage with the consequent breakdown of bioenergetics, that is, ATP depletion in both cell types. In this review, we summarize our knowledge of mitochondrial function and damage within both pancreatic acinar and ductal cells. We also suggest that colloidal ATP delivery systems for pancreatic energy supply may be able to protect acinar and ductal cells from cellular damage in the early phase of the disease. An effective energy delivery system combined with the prevention of further mitochondrial damage may, for the first time, open up the possibility of pharmacological therapy for acute pancreatitis, leading to reduced disease severity and mortality.

Effects of bile acids on pancreatic ductal bicarbonate secretion in guinea pig.

BACKGROUND AND AIMS: Acute pancreatitis is associated with significant morbidity and mortality. Bile reflux into the pancreas is a common cause of acute pancreatitis and, although the bile can reach both acinar and ductal cells, most research to date has focused on the acinar cells. The aim of the present study was to investigate the effects of bile acids on HCO(3)(-) secretion from the ductal epithelium. METHODS: Isolated guinea pig intralobular/interlobular pancreatic ducts were microperfused and the effects of unconjugated chenodeoxycholate (CDC) and conjugated glycochenodeoxycholate (GCDC) on intracellular calcium concentration ([Ca(2+)](i)) and pH (pH(i)) were measured using fluorescent dyes. Changes of pH(i) were used to calculate the rates of acid/base transport across the duct cell membranes. RESULTS: Luminal administration of a low dose of CDC (0.1 mM) stimulated ductal HCO(3)(-) secretion, which was blocked by luminal H(2)DIDS (dihydro-4,4'-diisothiocyanostilbene-2,2'-disulfonic acid). In contrast, both luminal and basolateral administration of a high dose of CDC (1 mM) strongly inhibited HCO(3)(-) secretion. Both CDC and GCDC elevated [Ca(2+)](i), and this effect was blocked by BAPTA-AM (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid), caffeine, xestospongin C and the phospholipase C inhibitor U73122. BAPTA-AM also inhibited the stimulatory effect of low doses of CDC on HCO(3)(-) secretion, but did not modulate the inhibitory effect of high doses of CDC. CONCLUSIONS: It is concluded that the HCO(3)(-) secretion stimulated by low concentrations of bile acids acts to protect the pancreas against toxic bile, whereas inhibition of HCO(3)(-) secretion by high concentrations of bile acids may contribute to the progression of acute pancreatitis.

The role of NF-kappaB activation in the pathogenesis of acute pancreatitis.

Acute pancreatitis is an inflammatory disease of the pancreas which, in its most severe form, is associated with multi-organ failure and death. Recently, signalling molecules and pathways which are responsible for the initiation and progression of this disease have been under intense scrutiny. One important signalling molecule, nuclear factor kappaB (NF-kappaB), has been shown to play a critical role in the development of acute pancreatitis. NF-kappaB is a nuclear transcription factor responsible for regulating the transcription of a wide variety of genes involved in immunity and inflammation. Many of these genes have been implicated as central players in the development and progression of acute pancreatitis. This review discusses recent advances in the investigation of pancreatic and extrapancreatic (lungs, liver, monocytes and macrophages, and endothelial cells) NF-kappaB activation as it relates to acute pancreatitis.

[Diagnosis of magnesium deficiency in the body, personal experience]. / Diagnostika deficitu horcíku v organismu, vlastní zkusenosti.

Magnesium as a component of a range of enzymatic systems is a very important intracellular cation in the organism. Its monitoring is limited in many observations only to determination of its concentration in blood serum. We have done an analysis of serum and erythrocyte magnesium concentrations in 23 healthy women, 70 healthy men and in 184 patients with ulcerative disease of gastroduodenum. It was proved in all the monitored groups that erythrocyte concentrations of magnesium were lower compared to values which were estimated from serum concentrations in 9 from 23 healthy women, in 3 from 60 healthy men, in 10 from 101 ill men with ulcerative gastroduodenal disease, and in 17 from 83 women with ulcerative gastroduodenal disease. The highest rate of low concentrations of erythrocyte magnesium in healthy women with physiologic concentrations of magnesium in serum was also confirmed by currently created subgroup of healthy women (n = 11) who undergone together with other analysis peroral Mg2+ load test. This test confirmed magnesium deficiency in 10 from 11 women. The results showed there are more frequent deficiencies of magnesium in organisms then it is generally assumed. They also proved the importance of nutrition and regular food in population of healthy, young women.

[Double blind randomized multicentre study of a seven-day eradication regime of Helicobacter pylori by omeprazole, clarithromycin and ornidazole vs. omeprazole, clarithromycin and metronidazole]. / Dvojite slepá, randomizovaná multicentrická studie 7denního eradikacního rezimu Helicobacter pylori omeprazolem, clarithromycinem a ornidazolem vs. omeprazolem, clarithomycinem a metronidazolem.

Effective eradication regimes of Helicobacter pylori infections are nowadays based on administration of a substance with a strong suppressive effect on production of gastric HCl combined with two antibiotics. As suppressor of gastric HCl production unequivocally some drug from the group of proton pump blockers is used. As to antibiotics, in first line therapy the following are recommended: clarithromycin, amoxicillin, metronidazole. A problem in the eradication therapy of Helicobacter pylori infection in recent years is the increasing resistance to clarithromycin and apparently also metronidazole. In the Czech Republic the resistance to clarithromycin in relation to Helicobacter pylori is stabilized at a level lower than 3.0 %. Resistance to metronidazole was reported in 1992 within the range of 24 % - 26 %, however in 2001 it was already 36.0 %. Therefore the question arises whether it is possible under our conditions to check the increasing metronidazole resistance by a drug which by its spectrum of action resembles metronidazole while it differs from it as to its chemical structure. This is the reason why the authors implemented a trial where metronidazole was replaced by tinodazole (Avrazor, Léciva Co.). The results revealed that in the group treated with tinidazole eradication was achieved after 7-day administration of ornidazole in 93.0 %, in the group where part of the eradication regime was metronidazole eradication was 82.6 %. The tolerance of both drugs was very good. The authors recommend to include the pattern omeprazole 2 x 20 mg, clarithromycin 2 x 500 mg and tinidazole 2 x 500 mg among first line therapeutic regimes.

Cholecystokinin fails to promote pancreatic regeneration in diabetic rats following the induction of experimental pancreatitis.

The aim of the present study was to investigate the spontaneous and cholecystokinin-octapeptide (CCK-8)-promoted laboratory changes and morphological alterations in rats with arginine (Arg)-induced pancreatitis in which diabetes had been induced with streptozotocin (STZ). Male Wistar rats were used in our experiments. Pancreatitis was induced by arginine, diabetes by STZ and regeneration was promoted by CCK-8. The serum amylase, glucose and insulin levels, the pancreatic contents of protein, DNA, amylase, trypsinogen and lipase, the pancreatic weight/body- weight ratio (pw/bw) and the plasma glucagon level were examined 1, 3, 7, 14 and 28 days after pancreatitis induction. Pancreatic tissue samples were examined by light microscopy and immunostaining on paraffin-embedded sections. The insulin and glucagon-containing cells were visualized by using monoclonal antibodies. The administration of low doses of CCK-8 accelerated the processes of regeneration following Arg-induced pancreatitis, but in rats that were also diabetic, pancreatic regeneration was not observed. The administration of low doses of CCK-8 seems to reduce the pancreatic beta -cell number and function in diabetic rats. The pancreatic endocrine function was further deteriorated by simultaneous Arg-induced pancreatitis. The diabetic state appeared to shift the normal pancreatic enzyme content (decreased amylase and increased trypsinogen) in this study.

Oxidative stress in distant organs and the effects of allopurinol during experimental acute pancreatitis.

BACKGROUND: The present study was aimed at an assessment of the role of oxygen-derived free radicals in the development of local and systemic manifestations of L-arginine (Arg)-induced acute pancreatitis and at an evaluation of the protective effect of the xanthine oxidase inhibitor allopurinol. METHODS: Acute pancreatitis was induced in male Wistar rats by injecting 2 x 250 mg/100 g body weight of Arg intraperitoneally at an interval of 1 h, as a 20% solution in 0.15 M NaCl. Control rats received the same quantity of glycine. In a third group, 200 mg/kg of allopurinol was administered subcutaneously 30 min before the first Arg injection. Rats were killed at 6, 12, 24, or 48 h following Arg administration. Acute pancreatitis was confirmed by a serum amylase level elevation and typical inflammatory features were observed microscopically. Tissue concentrations of malonyl dialdehyde (MDA), superoxide dismutase (Mn- and Cu,Zn-SOD), glutathione peroxidase (GPx), and catalase were measured in the pancreas, liver, and kidney. RESULTS: The tissue concentration of MDA was significantly elevated in each organ. The activities of Mn-SOD, Cu,Zn-SOD, GPx, and catalase were quickly depleted in the pancreas and kidney, whereas only the Mn-SOD and GPx activities were reduced in the liver after the onset of pancreatitis. Histologic examination revealed acinar cell necrosis in the pancreas, but only mild alterations in the liver and kidney. Allopurinol pretreatment prevented the generation of reactive oxygen metabolites in the pancreas and reduced their formation in the kidney. CONCLUSION: Oxygen-derived free radicals are generated in the pancreas, liver, and kidney at an early stage of Arg-induced acute pancreatitis. The liver and the kidney, but not the pancreas, are able to defend against oxidative stress. The prophylactic application of allopurinol significantly restrains the generation of free radicals in pancreas and kidney.

Effects of galanin(1-16) on pancreatic secretion in anesthetized and conscious rats.

Galanin, a 29-amino acid peptide, has been demonstrated in pancreatic nerve endings and found to inhibit insulin release in the rat. However, the data available concerning its effects on exocrine pancreatic secretion are contradictory. The aim of the present study was to evaluate the effects of a synthetic porcine galanin sequence, Gal(1-16), on stimulated pancreatic secretion in hyperglycemic anesthetized and conscious rats. Male Wistar rats were anesthetized and surgically prepared with pancreatic and femoral vein catheters. In anesthetized animals, the pancreatic secretion was continuously stimulated with 150 ng cholecystokinin octapeptide (CCK-8)/kg body weight per 30 min, dissolved in saline or 10% glucose. Synthetic Gal(1-16) (0.3 or 1 nmol/kg per h) was infused over a 60-min period. In conscious rats, 1, 3, or 10 nmol Gal(1-16)/kg per h was administered in a continuous saline or 10% glucose infusion over a 30-min period. The pancreatic secretory volume and protein output were determined in 30-min samples in both models. In anesthetized rats, 0.3 nmol Gal(1-16)/kg per h did not modify pancreatic secretion during CCK-8 stimulation. However, both the pancreatic secretory volume and the protein output were significantly inhibited compared with the basal levels by 1 nmol Gal(1-16)/kg per h. The inhibitory effect of Gal(1-16) on pancreatic secretion was more marked with CCK-8/glucose (53.9%) than with CCK-8/saline stimulation (20.1%). In conscious rats, significant inhibitory effects of 1 nmol Gal(1-16)/kg per h in saline were observed (18%). During glucose infusion, a dose-dependent inhibition of 1, 3, and 10 nmol Gal(1-16)/kg per h on pancreatic secretory volume and protein output (35% inhibition at 1 nmol/kg per h) was observed. In conclusion, the inhibitory effect of Gal(1-16) on exogenous and endogenous CCK-stimulated pancreatic secretion was found to be more potent in the presence of glucose both in anesthetized and in conscious rats. These results may suggest an indirect (insulin-mediated) inhibitory effect of porcine Gal(1-16) on pancreatic secretion in the rat.

The pathogenesis of L-arginine-induced acute necrotizing pancreatitis: inflammatory mediators and endogenous cholecystokinin.

This study was aimed at an assessment of the role of oxygen-derived free radicals, cytokines and endogenous cholecystokinin (CCK) in the pathogenesis of L-arginine (Arg)-induced acute pancreatitis in rat. We measured the levels of malonyl dialdehyde (MDA), glutathione peroxidase (GPx), catalase and superoxide dismutase (Mn- and Cu, Zn-SOD) in pancreatic tissue, the serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and CCK, and evaluated the protective effect of the xanthine oxidase inhibitor allopurinol and a novel CCK receptor antagonist KSG-504. Acute pancreatitis was induced in male Wistar rats by injecting 2x 250 mg/100 g body weight of Arg intraperitoneally in an 1-h interval, as a 20% solution in 0.15 M NaCl. Control rats received the same quantity of glycine. 200 mg x kg(-1) allopurinol 30 min before the first Arg treatment or 50 mg x kg(-1) KSG-504 30 min before and 6, 18 and 36 h after the first Arg injection was administered subcutaneously. Rats were killed at 6, 12, 24 and 48 h following Arg administration, and acute pancreatitis was confirmed by a serum amylase level elevation and typical inflammatory features observed microscopically. The serum level of amylase reached the peak level at 24 h after the Arg injection (30,800 +/- 3,813 versus 6,382 +/- 184 U x L(-1) in the control) and normalized at 48 h. The tissue concentration of MDA was significantly elevated at 24 h, and reached the peak value at 48 h (5.00 +/- 1.75 versus 0.28 +/- 0.05 nM x mg(-1) protein in the control). The catalase and Mn-SOD activities were significantly decreased throughout the study, while the GPx activity was significantly reduced at 6 and 12 h, and the Cu, Zn-SOD activity was significantly lower at 12 h after the Arg injection as compared with the controls. Both the TNF-alpha and the IL-6 levels were already elevated significantly at 12 h and peak at 24 h versus the controls (19.1 +/- 7.9 U x mL(-1) and 57.6 +/- 11.2 pg x mL(-1) versus 3.1 +/- 0.8 U x mL(-1) and 15.2 +/- 3.1 pg x mL(-1), respectively). No significant changes in plasma CCK levels were observed. Allopurinol treatment markedly reduced the serum amylase elevation (12.631 +/- 2.257 U x L(-1) at 24 h), prevented the increase in tissue MDA concentration (0.55 +/- 0.09 nM x mg(-1) protein at 48 h) and significantly ameliorated the pancreatic edema, necrosis and inflammation at 48 h after Arg administration. KSG-504 administration did not exert any beneficial effect on the development of histopathological changes neither modified the serum amylase or cytokine levels. Oxygen-derived free radicals and cytokines are involved, while endogenous CCK does not seem to play a role in the pathogenesis of Arg-induced acute pancreatitis.