Obesity is clearly an independent risk factor for increased severity of acute pancreatitis (AP), although the mechanisms underlying this association are unknown. Adipokines (including leptin and adiponectin) are pleiotropic molecules produced by adipocytes that are important regulators of the inflammatory response. We hypothesized that the altered adipokine milieu observed in obesity contributes to the increased severity of pancreatitis. Lean (C57BL/6J), obese leptin-deficient (LepOb), and obese hyperleptinemic (LepDb) mice were subjected to AP by six hourly intraperitoneal injections of cerulein (50 microg/kg). Severity of AP was assessed by histology and by measuring pancreatic concentration of the proinflammatory cytokines IL-1beta and IL-6, the chemokine MCP-1, and the marker of neutrophil activation MPO. Both congenitally obese strains of mice developed significantly more severe AP than wild-type lean animals. Severity of AP was not solely related to adipose tissue volume: LepOb mice were heaviest; however, LepDb mice developed the most severe AP both histologically and biochemically. Circulating adiponectin concentrations inversely mirrored the severity of pancreatitis. These data demonstrate that congenitally obese mice develop more severe AP than lean animals when challenged by cerulein hyperstimulation and suggest that alteration of the adipokine milieu exacerbates the severity of AP in obesity.
Background Peri-coronary epicardial adipose tissue (cEAT) serves as a metabolic and paracrine organ that contributes to inflammation and is associated with macrovascular coronary artery disease (CAD) development. While there is a strong correlation in humans between cEAT volume and CAD severity, there remains a paucity of experimental data demonstrating a causal link of cEAT to CAD. The current study tested the hypothesis that surgical resection of cEAT attenuates inflammation and CAD progression. Methods Female Ossabaw miniature swine (n=12) were fed an atherogenic diet for 8 months and randomized into sham (n=5) or adipectomy (n=7) groups. Both groups underwent a thoracotomy, opening of the pericardial sac, and placement of radio-opaque clips to mark the proximal left anterior descending artery. Adipectomy swine underwent removal of 1–1.5 cm2 of cEAT from the proximal artery. Following sham or adipectomy, CAD severity was assessed with intravascular ultrasound. Swine recovered for an additional 3 months on atherogenic diet and CAD was assessed immediately prior to euthanasia. Artery sections were processed for histological and immunohistochemical analysis. Results CAD severity, as assessed by percent stenosis, was reduced in the adipectomy cohort compared to shams; however, plaque size remained unaltered, while sham-operated swine developed greater plaque sizes. Adipectomy resulted in an expanded arterial diameter, similar to the Glagov phenomenon of positive outward remodeling. No differences in inflammatory marker expression were observed. Conclusions These data indicate that cEAT resection did not alter inflammatory marker expression, but arrested CAD progression through increased positive outward remodeling and arrest of atherogenesis.
Objectives The aims of this study were to characterize the proteome of normal pancreatic juice, to analyze the effect of secretin on the normal proteome, and to compare these results with published data from patients with pancreatic cancer. Methods Paired pancreatic fluid specimens (before and after intravenous secretin stimulation) were obtained during endoscopic pancreatography from three patients without significant pancreatic pathology. Proteins were identified and quantified by mass spectrometry-based protein quantification technology. The human RefSeq (NCBI) database was used to compare the data in normal patient samples with published data from three pancreatic cancer patients. Results A total of 285 proteins were identified in normal pancreatic juice. Ninety had sufficient amino acid sequences identified to characterize the protein with a high level of confidence. All 90 proteins were present before and after secretin administration but with altered relative concentrations, usually by 1-2 folds, after stimulation. Comparison with 170 published pancreatic cancer proteins yielded an overlap of only 42 proteins. Conclusions Normal pancreatic juice contains multiple proteins related to many biological processes. Secretin alters the concentration but not the spectrum of these proteins. The pancreatic juice proteome of normal and pancreatic cancer patients differ markedly.
Microtubules are ubiquitous in eukaryotic cells and play key roles in many cellular activities. The purpose of this study was to investigate the influence of microtubules on vascular smooth muscle contraction. Quantitative immunocytochemical analysis of rat aortic tissue revealed that, relative to the control group, colchicine (15 muM, 90 min) and nocodazole (15 muM, 90 min) decreased the microtubule density by 40-50% while taxol (10 muM, 90 min) increased the microtubule density by 33%. Isometric contraction studies demonstrated that both colchicine and nocodazole caused an upward shift in the phenylephrine (10(-8) to 10(-5) M) dose-response curve while taxol caused no significant change when compared to the control group. Potassium chloride (30 mM) induced 55 +/- 5% P0 contraction in DMSO treated vessel rings. The active tension increased to 73 +/- 5% P0 and 71 +/- 6% P0 after pretreatment of the aortic rings with colchicine or nocodazole, respectively. Taxol did not cause a significant change in the active tension (56 +/- 7% P0). These results indicate that microtubule depolymerization enhances isometric contraction of vascular smooth muscle and this enhanced contraction is not receptor dependent. Pretreatment of the aortic rings with an inhibitor of nitric oxide synthase (NOS) (Nomega-nitro-L-arginine) did not change the increased contractile response to phenylephrine due to microtubule depolymerization suggesting that this phenomenon is not mediated by endothelium dependent relaxation.
Dysregulation of gallbladder ion and water absorption and/or secretion has been linked to cholesterol crystal and gallstone formation. We have recently demonstrated that obese, leptin-deficient (Lep(ob)) mice have enlarged gallbladder volumes and decreased gallbladder contractility and that leptin administration to these mice normalizes gallbladder function. However, the effect of leptin on gallbladder absorption/secretion is not known. Therefore, we sought to determine whether leptin would alter the expression of genes involved in water and ion transport across the gallbladder epithelium. Affymetrix oligonucleotide microarrays representing 39,000 transcripts were used to compare gallbladder gene-expression profiles from 12-wk-old control saline-treated Lep(ob) and from leptin-treated Lep(ob) female mice. Leptin administration to Lep(ob) mice decreased gallbladder volume, bile sodium concentration, and pH. Leptin repletion upregulated the expression of aquaporin 1 water channel by 1.3-fold and downregulated aquaporin 4 by 2.3-fold. A number of genes involved in sodium transport were also influenced by leptin replacement. Epithelial sodium channel-alpha and sodium hydrogen exchangers 1 and 3 were moderately downregulated by 2.0-, 1.6-, and 1.3-fold, respectively. Carbonic anhydrase-IV, which plays a role in the acidification of bile, was upregulated 3.7-fold. In addition, a number of inflammatory cytokines that are known to influence gallbladder epithelial cell absorption and secretion were upregulated. Thus leptin, an adipocyte-derived cytokine involved with satiety and energy balance, influences gallbladder bile volume, sodium, and pH as well as multiple inflammatory cytokine genes and genes related to water, sodium, chloride, and bicarbonate transport.
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