Morphology Of Pancreas Research Articles

The glucose-lowering effects of the PDE4 inhibitors roflumilast and roflumilast-N-oxide in db/db mice

The cAMP-degrading phosphodiesterase 4 (PDE4) enzyme has recently been implicated in the regulation of glucagon-like peptide-1 (GLP-1), an incretin hormone with glucose-lowering properties. We investigated whether the PDE4 inhibitor roflumilast elevates GLP-1 levels in diabetic db/db mice and whether this elevation is accompanied by glucose-lowering effects. Plasma GLP-1 was determined in db/db mice after single oral administration of roflumilast or its active metabolite roflumilast-N-oxide. Diabetes-relevant variables including HbA(1c), blood glucose, serum insulin, body weight, food and water intake, and pancreas morphology were determined in db/db mice treated daily for 28 days with roflumilast or roflumilast-N-oxide. Pharmacokinetic/pharmacodynamic analysis clarified the contribution of roflumilast vs its metabolite. In addition, the effect of roflumilast-N-oxide on insulin release was investigated in primary mouse islets. Single treatment of db/db mice with 10 mg/kg roflumilast or roflumilast-N-oxide enhanced plasma GLP-1 2.5- and fourfold, respectively. Chronic treatment of db/db mice with roflumilast or roflumilast-N-oxide at 3 mg/kg showed prevention of disease progression. Roflumilast-N-oxide abolished the increase in blood glucose, reduced the increment in HbA(1c) by 50% and doubled fasted serum insulin compared with vehicle, concomitant with preservation of pancreatic islet morphology. Furthermore, roflumilast-N-oxide amplified forskolin-induced insulin release in primary islets. Roflumilast-N-oxide showed stronger glucose-lowering effects than its parent compound, consistent with its greater effect on GLP-1 secretion and explainable by pharmacokinetic/pharmacodynamic modelling. Our results suggest that roflumilast and roflumilast-N-oxide delay the progression of diabetes in db/db mice through protection of pancreatic islet physiology potentially involving GLP-1 and insulin activities.

Trypanosoma cruzi infection alters glucose metabolism at rest and during exercise without modifying the morphology of pancreatic islets in rats

This study investigated the effects of Trypanosoma cruzi infection on pancreatic morphology and glucose metabolism at rest and during exercise. Wistar rats were randomized into control (CG=10) and infected (IG=10) groups. The IG animals were inoculated with T. cruzi Y strain (300,000 trypomastigotes/50g). After 9 weeks, the animals were subjected to glucose (OGTT) and insulin (ITT) tolerance tests and a treadmill running protocol. Blood glucose, lactate and time to fatigue were determined. After euthanasia, the pancreases were removed for morphological and biochemical analyses. The IG presented abnormal glucose kinetics in OGTT and a similar glucose curve in ITT compared to the CG. During the exercise test, the IG showed anticipation of time to fatigue. At the point of fatigue, no difference was found in blood glucose and lactate between the groups. There was a significant correlation between lactate levels and the time to fatigue. The IG presented marked pancreatic inflammation, fibrosis and protein oxidation. The number of β cells in the IG animals was not reduced. T. cruzi infection impaired pancreas morphology and glucose metabolism at rest and during exercise in rats, which could constitute an additional mechanism in the induction of exercise intolerance in Chagas’ disease.

Nonlinear Optical Microscopy for Histology of Fresh Normal and Cancerous Pancreatic Tissues

BackgroundPancreatic cancer is a lethal disease with a 5-year survival rate of only 1–5%. The acceleration of intraoperative histological examination would be beneficial for better management of pancreatic cancer, suggesting an improved survival. Nonlinear optical methods based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) of intrinsic optical biomarkers show the ability to visualize the morphology of fresh tissues associated with histology, which is promising for real-time intraoperative evaluation of pancreatic cancer.Methodology/Principal FindingsIn order to investigate whether the nonlinear optical imaging methods have the ability to characterize pancreatic histology at cellular resolution, we studied different types of pancreatic tissues by using label-free TPEF and SHG. Compared with other routine methods for the preparation of specimens, fresh tissues without processing were found to be most suitable for nonlinear optical imaging of pancreatic tissues. The detailed morphology of the normal rat pancreas was observed and related with the standard histological images. Comparatively speaking, the preliminary images of a small number of chemical-induced pancreatic cancer tissues showed visible neoplastic differences in the morphology of cells and extracellular matrix. The subcutaneous pancreatic tumor xenografts were further observed using the nonlinear optical microscopy, showing that most cells are leucocytes at 5 days after implantation, the tumor cells begin to proliferate at 10 days after implantation, and the extracellular collagen fibers become disordered as the xenografts grow.Conclusions/SignificanceIn this study, nonlinear optical imaging was used to characterize the morphological details of fresh pancreatic tissues for the first time. We demonstrate that it is possible to provide real-time histological evaluation of pancreatic cancer by the nonlinear optical methods, which present an opportunity for the characterization of the progress of spontaneous pancreatic cancer and further application in a non-invasive manner.

Preliminary study on mechanisms of total saponins from Entada phaseoloides against diabetes

To study the effect of total saponins from Entada phaseoloides (TSEP) on islet morphology and skeletal muscle PI3K pathway-related protein expression of type 2 diabetic rats. Type 2 diabetic rats were induced by high-fat diet and low-dose streptozotocin and then randomly divided into 5 groups, i.e. the normal control, the model group, the positive control drug (200 mg x kg(-1) metformin), the low-dose TSEP (25 mg x kg(-1)) group and the high-dose TSEP (50 mg x kg(-1)). Three weeks later, the islet morphology of rat pancreas were observed by HE staining, and protein expressions of insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), protein tyrosine phosphatase-1B (PTP-1 B) and glucose transporter 4 (GLUT4) in rat skeletal muscle were detected by Western blot. Compared with the modal group, TSEP administration groups showed relatively normal structures, clear pancreatic cells and intact capsula structures in pancreatic tissue pathological sections, with the number of pancreatic islets close to the normal control group. Meanwhile, above TSEP administration groups showed increased IRS-1, PI3K and GLUT4 protein expressions in their skeletal muscle tissues and decreased PTP-1B protein expression compared with the model group. TSEP has an effect on protecting pancreatic tissues of type 2 diabetic rats and intervening in abnormal expression of proteins in skeletal muscle tissues.

Islet microarchitecture and glucose transporter expression of the pancreas of the marmoset monkey display similarities to the human

The common marmoset New World monkey (Callithrix jacchus), is a primate model with great potential for scientific research, including research on diabetes. However, in opposite to Rhesus and Java monkeys (Macaca mulatta and Macaca fascicularis) little is known about the marmosets islet microarchitecture, glucose transporter and pancreatic marker gene expression. In this work we analyze differences and similarities in size, shape, cellular composition and intra-islet topography between the common marmoset and the human endocrine pancreas. Different sized, circular and a-circular shaped islets of the common marmoset and human display α-cells in the whole islet organ leading to a ribbon-like islet type. The number of islets was significantly higher in the common marmoset compared with humans. However, the area of insulin-producing cells was significantly higher in the human pancreas. Intra-islet distribution pattern of δ- and β-cells was similar in both species. The morphology of the exocrine pancreas regarding acinar and ductal cells was quite similar as confirmed by ultrastructural analysis. Additionally the ultrastructure of secretory granules from α-, δ- and β-cells of human and non-human primate pancreas showed the same characteristics. Molecular analysis showed the presence of endocrine pancreatic marker genes like PMCA2, NCX1, SUR1, KIR6.2, MAFA, NGN3 and PDX1 also expressed in the human. For the first time we could show presence of Glut 5 and 9 transporters in addition to the low abundance transporter Glut2 and the highly expressed Glut1 glucose transporter. We propose that Callithrix jacchus displays a new animal model for diabetes research and regenerative medicine.

The Effects of Systemic Administration of Amylin on the Pancreas of Laying Hens

The aim of present study was to investigate the effects of systemic administration of amylin in laying hens and also to examine the localisation of amylin in the pancreas of laying hens at three different ages. It involved a variety of histological, immunohistochemical, and biochemical techniques. Thirty Super Nick laying hens of 10 weeks of age were used. The control group had no treatment. On alternate days the experimental group was injected subcutaneously in the loose skin at the nape of neck with recombinant rat amylin prepared in water at a dose of 75 μg kg−1. The morphology of pancreas was studied at 14, 16, and 18 weeks of age. Our immunohistochemical results conclusively showed that amylin was expressed in beta cells and yet to our knowledge, this is the first study to report the expression of amylin in serous acini of 14 and 16 weeks of age. It can be concluded that systemically administered amylin increased the stimulation of amylin synthesis from pancreas and also increased plasma amylin levels especially at 16 weeks of age.

Breviscapine attenuates acute pancreatitis by inhibiting expression of PKCα and NF-κB in pancreas

To study the effect of breviscapine (Bre) on activity of protein kinase Cα (PKCα) and nuclear factor (NF)-κB in pancreas, and the mechanism of Bre attenuating acute pancreatitis (AP). One hundred and eight rats were randomly divided into acute necrotizing pancreatitis (ANP) group, Bre group (ANP + Bre group) and sham operation (SO) group, 36 rats in each group. ANP model was induced by a retrograde injection of 4% sodium deoxycholate into the bilio-pancreatic duct. Fifteen minutes after the ANP model was induced, the rats in Bre group were intraperitoneally injected with Bre (0.4 mg/100 g body weight or 0.1 mL/100 g body weight). Survival time and mortality of rats were calculated. Serum amylase and malondialdehyde levels were measured, volume of ascites was recorded and morphology of pancreas and lung was evaluated at 1, 5 and 10 h, after the ANP model was induced, respectively. Expressions of PKCα and subunit p65 of NF-κB in pancreas were detected by immunohistochemistry and Western blotting. The life span of rats was longer and the mortality was lower in Bre group than in ANP group 13.51 ± 5.46 vs. 25.36 ± 8.11 (P < 0.05). The amylase and MDA levels as well as the volume of ascites were lower and the pathological changes in pancreas and lung were less in Bre group than ANP group (P < 0.05), indicating that the pancreatitis is less severe in Bre group than ANP group. The activation of PKCα and NF-κB p65 in pancreas was induced rapidly and reached their peak at 1 h or 5 h after ANP, but their activity in Bre group was significantly inhibited. Bre exerts its therapeutic effect on AP by inhibiting the activation of PKCα and NF-κB p65 in pancreas.

Nutritional programming of pancreatic β-cell plasticity

Nutritional insufficiency during pregnancy has been shown to alter the metabolism of the offspring and can increase the risk of type 2 diabetes. The phenotype in the offspring involves changes to the morphology and functional capacity of the endocrine pancreas, and in the supporting islet microvasculature. Pancreatic β-cells possess a plastic potential and can partially recover from catastrophic loss. This is partly due to the existence of progenitors within the islets and the ability to generate new islets by neogenesis from the pancreatic ducts. This regenerative capacity is induced by bone marrow-derived stem cells, including endothelial cell progenitors and is associated with increased angiogenesis within the islets. Nutritional insults in early life, such as feeding a low protein diet to the mother, impair the regenerative capacity of the β-cells. The mechanisms underlying this include a reduced ability of β-cells to differentiate from the progenitor population, changes in the inductive signals from the microvasculature and an altered presence of endothelial progenitors. Statin treatment within animal models was associated with angiogenesis in the islet microvasculature, improved vascular function and an increase in β-cell mass. This demonstrates that reversal of the impaired β-cell phenotype observed following nutritional insult in early life is potentially possible.

The effects of acquired paternal obesity on the next generation

The effects of acquired paternal obesity on the next generation

Blood glucose and morphology of the liver and pancreas in garlic-fed Wistar rats.

The effect of aqueous fresh garlic (Allium sativum) cloves extracts on blood glucose level and on the morphology of liver and pancreas of Wistar rats was determined. Four groups of 5 each of preweighed male and female (controls) as well as 5 each of male and female experimental Wistar albino rats were administered with 500 mg/kg body weight of extracts for 12 weeks and blood glucose analysis was done after a 10 h fast before and at the 3rd, 6th, 9th and 12thweek of garlic administration and the liver and pancreas were also taken for histological analysis. Results showed that at the end of the 3rd and 6th week of garlic administration, there was a slight decrease in blood glucose levels in both the male and female rats, and at the end of the 9th and 12th week, there was a very significant decrease in the blood glucose levels of both the male and female garlic-fed rats. There were morphological changes in the liver and pancreas of the garlic-fed rats. The results suggest that chronic garlic feeding decreases blood glucose level. Key words: Garlic, blood glucose level, liver, pancreas.

Linoleic acid supplement in cystic fibrosis: friend or foe?

Linoleic acid supplement in cystic fibrosis: friend or foe?

Hyperglycaemia but not hyperlipidaemia decreases serum amylase and increases neutrophils in the exocrine pancreas of cats

The goal of the study was to determine whether hyperglycaemia or hyperlipidaemia causes pancreatitis in cats and to assess the effect of excess serum glucose and lipids on amylase and lipase activity. Ten-day hyperglycaemic and hyperlipidaemic clamps were carried out in five and six healthy cats, respectively. Ten healthy cats received saline and served as controls. The activity of amylase was below the normal range in 4 of 5 hyperglycaemic cats by day 10. The activity of lipase did not vary in any of the cats. Samples of exocrine pancreas were normal on histological examination, but the number of tissue neutrophils was increased in hyperglycaemic cats (P<0.05). In a retrospective study 14 of 40 (35%) cats with naturally occurring diabetes mellitus had amylase activities below the reference range at the time of admission. Amylase activities normalised within 1 week of insulin therapy and subsequent glycaemic control. Lipase activity was increased in 26 of 40 (65%) diabetic cats and remained elevated despite glycaemic control. In conclusion, hyperglycaemia, but not hyperlipidaemia, increases pancreatic neutrophils in cats. However, because the histological morphology of the exocrine pancreas was normal, hyperglycaemia may play only a minor role in the pathogenesis of pancreatitis. Low amylase activities in diabetic cats may reflect an imbalance in glucose metabolism rather than pancreatitis.

424 DOMINANT-NEGATIVE GLUCOSE-DEPENDENT INSULINOTROPIC POLYPEPTIDE (GIP) RECEPTOR (GIPRdn)TRANSGENIC PIGS — A LARGE ANIMAL MODEL FOR TYPE 2 DIABETES MELLITUS

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted in response to nutrients and enhance glucose-induced insulin secretion. The insulinotropic action of GIP is impaired in type 2 diabetes (T2D) whereas that of GLP-1 is preserved. To evaluate the role of an impaired GIP function in the pathogenesis of T2D in a large animal model, we generated transgenic pigs expressing a dominant-negative GIP receptor (GIPRdn) in the pancreatic islets. GIPRdn transgenic pigs were generated using lentiviral transgenesis. Metabolic tests and quantitative stereological analyses of the pancreas were performed in 3 different age groups to investigate the effects of an impaired insulinotropic action of GIP on glucose metabolism and pancreas morphology. The insulinotropic action of GIP was significantly reduced, whereas insulin secretion in response to the GLP-1 receptor agonist exendin-4 was enhanced in 11-week-old GIPRdn transgenic pigs compared with control pigs. Eleven-week-old GIPRdn transgenic pigs (n = 5) exhibited significantly reduced oral glucose tolerance (P &lt; 0.05) with a delay in insulin secretion compared with controls (n = 5). The area under the insulin curve (AUC) during the first 45 min following glucose load was 31% smaller (P &lt; 0.05) in transgenic pigs compared with controls. The total insulin secretion capacity was not different between the 2 groups indicating that GIPRdn expression initially only interferes with the incretin effect. This was supported by the fact that intravenous glucose tolerance and insulin secretion in transgenic pigs were not different from controls. Five-month-old GIPRdn transgenic pigs revealed markedly reduced insulin secretion in response to oral glucose challenge (P &lt; 0.01), resulting in significantly elevated glucose levels (P &lt; 0.05). Also, intravenous glucose tolerance and insulin secretion were diminished in 11-month-old transgenic pigs. To determine the reason for the alterations in glucose metabolism, quantitative-stereological analyses of the pancreas were performed. In 11-week-old pigs, transgenic and control groups showed similar β-cell mass (n = 5 in each group). However, pancreatic β-cell mass was reduced by almost 40% (P &lt; 0.05) in 5-month-old pigs and by 60% (P &lt; 0.01) in adult (1 to 1.4 years) GIPRdn transgenic pigs compared with controls. To investigate the reason for the progressive reduction of pancreatic β-cell mass in GIPRdn transgenic pigs, β-cell proliferation rate was determined performing a double-immunohistochemistry for insulin and the proliferation marker Ki67. Eleven-week-old GIPRdn transgenic pigs showed significantly fewer Ki67-positive cell nuclei compared with controls (P &lt; 0.05). In conclusion, GIPRdn transgenic pigs exhibit a comparable situation to T2D, such as impaired insulinotropic action of GIP, disturbed oral and intravenous glucose tolerance, and progressive reduction of β-cell mass. These alterations are at least partly attributable to diminished proliferation of β-cells. Grant support: Deutsche Forschungsgemeinschaft (GRK 1029), Bayerische Forschungsstiftung (492/02).

Long-Term Prognosis of Acute Pancreatitis in Japan

This study was undertaken to evaluate the long-term prognosis of acute pancreatitis (AP) in Japan and to identify factors that predict major complications. In 1987, 2533 patients with moderate or severe acute pancreatitis were registered in a national survey in Japan. Follow-up studies were done in 2000 and in 2004 to evaluate recurrence of acute pancreatitis, transition to chronic pancreatitis, development of diabetes mellitus, and mortality. The relationship between incidence of complications and alcohol consumption during follow-up period was also analyzed. Valid replies were obtained from 714 cases in 2000 and 450 cases in 2004. Recurrence of acute pancreatitis occurred in 145 cases, and the recurrence rate was significantly higher in alcoholic pancreatitis compared with other etiologies. A transition to chronic pancreatitis occurred frequently in alcoholic pancreatitis and inversely correlated with existence of pancreatic necrosis in the initial disease. Complication with diabetes mellitus and the transition to chronic pancreatitis strongly correlated with persistent alcohol intake during follow-up period. During the follow-up period, 199 patients died, and 43 died of malignant disease. Recurrence of acute pancreatitis and a transition to chronic pancreatitis frequently occurred in alcoholic pancreatitis. Transition to chronic pancreatitis was inversely correlated with the existence of pancreatic necrosis at the initial presentation. Mortality as a result of malignant disease was not excessive in the patients with history of acute pancreatitis.

Disruption of GPR39 Impairs Insulin Secretion In Vivo

GPR39 is a G protein-coupled receptor expressed in liver, gastrointestinal tract, adipose tissue and pancreas. We have recently shown that young GPR39 mice have normal body weight, food intake, and fasting glucose and insulin levels. In this study, we examined the role of GPR39 in aging and diet-induced obese mice. Body weight and food intake were similar in wild-type (WT) and GPR39 / mice as they aged from 12 to 52 weeks or when fed a low-fat/high-sucrose (LFHS) or high-fat/high-sucrose (HFHS) diet. 52-week-old GPR39 / mice showed a trend toward decreased insulin levels after oral glucose challenge. When fed either a LFHS or HFHS diet, GPR39 / mice had increased fed glucose levels and showed decreased serum insulin levels during an oral glucose tolerance test in the face of unchanged insulin tolerance. Pancreas morphology and glucose-stimulated insulin secretion in isolated islets from WT and GPR39 / mice were comparable, suggesting that GPR39 is not required for pancreas development or ex vivo insulin secretion. Small interfering RNA-mediated knockdown of GPR39 in clonal NIT-1 -cells revealed that GPR39 regulates the expression of IRS-2 and PDX-1 in a cell-autonomous manner; IRS-2 mRNA was also significantly decreased in the pancreas of GPR39 / mice. Taken together, our data indicate that GPR39 is required for the increased insulin secretion in vivo under conditions of increased demand, i.e. upon development of age-dependent and diet-induced insulin resistance. Thus, GPR39 agonists may have potential for the treatment of type 2 diabetes. Minireview: Thyrotropin-Releasing Hormone and the Thyroid Hormone Feedback Mechanism Maria Izabel Chiamolera and Fredric E. Wondisford (Endocrinology, published January 29, 2009, 10.1210/en.2008-1795) ABSTRACT Thyroid hormone (TH) plays a critical role in development, growth, and cellular metabolism. TH production is controlled by a complex mechanism of positive and negative regulation. Hypothalamic TRH stimulates TSH secretion from the anterior pituitary. TSH then initiates TH synthesis and release from the thyroid gland. The synthesis of TRH and TSH subunit genes is inhibited at the transcriptional level by TH, which also inhibits posttranslational modification and release of TSH. Although opposing TRH and TH inputs regulate the hypothalamic-pituitary-thyroid axis, TH negative feedback at the pituitary was thought to be the primary regulator of serum TSH levels. However, study of transgenic animals showed an unexpected, dominant role for TRH in regulating the hypothalamic-pituitary-thyroid axis and an unanticipated involvement of the thyroid hormone receptor ligand-dependent activation function (AF-2) domain in TH negative regulation. These results are summarized in the review. T R A N S L A T I O N A L H I G H L I G H T S F R O M E N D O C R I N O L O G YThyroid hormone (TH) plays a critical role in development, growth, and cellular metabolism. TH production is controlled by a complex mechanism of positive and negative regulation. Hypothalamic TRH stimulates TSH secretion from the anterior pituitary. TSH then initiates TH synthesis and release from the thyroid gland. The synthesis of TRH and TSH subunit genes is inhibited at the transcriptional level by TH, which also inhibits posttranslational modification and release of TSH. Although opposing TRH and TH inputs regulate the hypothalamic-pituitary-thyroid axis, TH negative feedback at the pituitary was thought to be the primary regulator of serum TSH levels. However, study of transgenic animals showed an unexpected, dominant role for TRH in regulating the hypothalamic-pituitary-thyroid axis and an unanticipated involvement of the thyroid hormone receptor ligand-dependent activation function (AF-2) domain in TH negative regulation. These results are summarized in the review. T R A N S L A T I O N A L H I G H L I G H T S F R O M E N D O C R I N O L O G Y

Increased insulin sensitivity in mice lacking collectrin, a downstream target of HNF-1alpha.

Collectrin is a downstream target of the transcription factor hepatocyte nuclear factor-1alpha (HNF-1alpha), which is mutated in maturity-onset diabetes of the young subtype 3 (MODY3). Evidence from transgenic mouse models with collectrin overexpression in pancreatic islets suggests divergent roles for collectrin in influencing beta-cell mass and insulin exocytosis. To clarify the function of collectrin in the pancreas, we used a mouse line with targeted deletion of the gene. We examined pancreas morphology, glucose homeostasis by ip glucose tolerance testing (IPGTT) and insulin tolerance testing (IPITT), and pancreas function by in vivo acute-phase insulin response determination and glucose-stimulated insulin secretion from isolated islets. We find no difference in either pancreas morphology or function between wild-type and collectrin-deficient animals (Tmem27(-/y)). However, we note that by 6 months of age, Tmem27(-/y) mice exhibit increased insulin sensitivity by IPITT and decreased adiposity by dual-energy x-ray absorptiometry scanning compared with wild-type. We have previously reported that Tmem27(-/y) mice exhibit profound aminoaciduria due to failed renal recovery. We now demonstrate that Tmem27(-/y) animals also display inappropriate excretion of some short-chain acylcarnitines derived from amino acid and fatty acid oxidation. We provide further evidence for compensatory up-regulation of oxidative metabolism in Tmem27(-/y) mice, along with enhanced protein turnover associated with preserved lean mass even out to 1.5 yr of age. Our studies suggest that collectrin-deficient mice activate a number of adaptive mechanisms to defend energy homeostasis in the setting of ongoing nutrient losses.

Disruption of G Protein-Coupled Receptor 39 Impairs Insulin Secretion in Vivo

GPR39 is a G protein-coupled receptor expressed in liver, gastrointestinal tract, adipose tissue, and pancreas. We have recently shown that young GPR39(-/-) mice have normal body weight, food intake, and fasting glucose and insulin levels. In this study, we examined the role of GPR39 in aging and diet-induced obese mice. Body weight and food intake were similar in wild-type and GPR39(-/-) mice as they aged from 12 to 52 wk or when fed a low-fat/high-sucrose or high-fat/high-sucrose diet. Fifty-two-week-old GPR39(-/-) mice showed a trend toward decreased insulin levels after oral glucose challenge. When fed either a low-fat/high-sucrose or high-fat/high-sucrose diet, GPR39(-/-) mice had increased fed glucose levels and showed decreased serum insulin levels during an oral glucose tolerance test in the face of unchanged insulin tolerance. Pancreas morphology and glucose-stimulated insulin secretion in isolated islets from wild-type and GPR39(-/-) mice were comparable, suggesting that GPR39 is not required for pancreas development or ex vivo insulin secretion. Small interfering RNA-mediated knockdown of GPR39 in clonal NIT-1 beta-cells revealed that GPR39 regulates the expression of insulin receptor substrate-2 and pancreatic and duodenal homeobox-1 in a cell-autonomous manner; insulin receptor substrate-2 mRNA was also significantly decreased in the pancreas of GPR39(-/-) mice. Taken together, our data indicate that GPR39 is required for the increased insulin secretion in vivo under conditions of increased demand, i.e. on development of age-dependent and diet-induced insulin resistance. Thus, GPR39 agonists may have potential for the treatment of type 2 diabetes.

Endocrine pancreas development at weaning in goat kids

Eighteen three-day old Saanen goat kids were divided into MILK and WEAN groups. MILK kids received goat milk to age 48 days; WEAN kids were initially fed milk but started weaning at 25 days and were completely weaned by 40 days. Total intake per group was recorded daily. On day 25, 40 and 48, body weights were recorded, and plasma samples were taken and analyzed for glucose, free amino-acids and insulin. On day 48, all animals were slaughtered and pancreas samples were analyzed for total DNA and RNA content. Histological sections of pancreas were examined by light microscope and images analyzed by dedicated software. Seve days after the beginning of the weaning program, dry matter intake in the WEAN group began to decrease compared to the MILK one. Nonetheless, body weight did not differ throughout the study period. Weaning significantly decreased plasma levels of glucose, amino-acids and insulin. No difference was observed in pancreatic DNA and RNA content. Histological analysis of pancreas showed that the size of pancreatic islets was not different, but islet number per section was lower in the pancreas of WEAN animals. In conclusion, weaning affects glucose and amino-acid metabolism and influences endocrine pancreas activity and morphology.

Pancreatic Response to Hind Limb Suspension in Rats is Affected by Age

Disuse and aging are associated with changes in glucose metabolism and insulin responsiveness of skeletal muscle. However, their combined effects on the islets of Langerhans in the pancreas and serum insulin levels have not been studied. The goal of this study was to investigate the response of the pancreas to disuse, induced by hind limb sus- pension (HS), in young and old animals. Male Fisher 344 X Brown Norway rats at 6 (young) and 32 (old) months of age were subjected to 14 days HS. Serum insulin and pancreas morphology were examined. Serum insulin concentration was lower in old rats, and decreased significantly following HS in young, but not old rats. Islets of Langerhans in the pancreas showed a more diffuse appearance in the old rats independent of HS, but no statistically significant differences were ob- served in islet area, cells per islet, or area occupied by islets. However, in old animals, but not young, HS was associated with an increase in islet number. No differences were observed in the percentage or area of insulin positive cells in the pancreas. We conclude that the insulin secretion response to disuse is lost at old age, and this can not be explained by changes in islet size or insulin positive cell number. The implications of changed appearance and number of islets in old rats in response to HS remain to be investigated.

TOWARD IMPROVED SURGICAL TECHNIQUES FOR PIG PANCREAS PROCUREMENT

Background: Warm ischemia time (WIT) and elevated temperature during pancreas procurement can significantly affect the viability of transplanted tissue. Quantitative information on these parameters is currently lacking and needed. Aim: To evaluate and optimize the efficiency, effectiveness, and practicality of existing and emergent pancreas procurement techniques in non-heart beating donor pigs by measuring the WIT and the organ temperature in situ. Methods: Pancreata were removed by en bloc viscerectomy from 81 female Landrace pigs. The first procurement method (27%) utilized only crushed ice for cooling. The second method (25%) utilized crushed ice and a vascular flush of cold preservation solution by cannulation of the suprarenal aorta. A third method (48%) was developed to selectively flush through the celiac trunk (CT) and the superior mesenteric artery (SMA). Ductal infusion with preservation solution was also investigated in conjunction with all three methods. Temperature measurements were taken by needle probe in several organs. Results: Vascular flush (methods 2 and 3) resulted in improved cooling and macroscopic pancreas morphology compared to surface cooling (method 1) which can take >30 min to cool the core to 4 °C. Method 3 eliminates solution waste without increasing WIT. Ductal infusion improved organ cooling but was not as effective as the vascular flush. Conclusions: Selective CT and SMA flush with cold storage solution in conjunction with ductal infusion promotes rapid cooling and improves pancreas preservation.