Pancreas Of Streptozotocin-induced Diabetic Rats Research Articles

Effects of Creatine Supplementation on Histopathological and Biochemical Parameters in the Kidney and Pancreas of Streptozotocin-Induced Diabetic Rats.

Diabetes mellitus (DM) is a worldwide health concern, and projections state that cases will reach 578 million by 2030. Adjuvant therapies that can help the standard treatment and mitigate DM effects are necessary, especially those using nutritional supplements to improve glycemic control. Previous studies suggest creatine supplementation as a possible adjuvant therapy for DM, but they lack the evaluation of potential morphological parameters alterations and tissue injury caused by this compound. The present study aimed to elucidate clinical, histomorphometric, and histopathological consequences and the cellular oxidative alterations of creatine supplementation in streptozotocin (STZ)-induced type 1 DM rats. We could estimate whether the findings are due to DM or the supplementation from a factorial experimental design. Although creatine supplementation attenuated some biochemical parameters, the morphological analyses of pancreatic and renal tissues made clear that the supplementation did not improve the STZ-induced DM1 injuries. Moreover, creatine-supplemented non-diabetic animals were diagnosed with pancreatitis and showed renal tubular necrosis. Therefore, even in the absence of clinical symptoms and unaltered biochemical parameters, creatine supplementation as adjuvant therapy for DM should be carefully evaluated.

Effect of Propolis Administration on the Endocrine Functions and Histopathology of Pancreas in Streptozotocin-Induced Diabetic Rats

This study was performed to investigate the hypoglycemic properties of Propolis and their possible role on pancreatic's tissue. Diabetes mellitus was induced in 45 adult male albino rats and the animals were divided into three groups; Negative control group received standard diet; Positive group diabetic untreated group; Propolis treated group supplemented with (0.3 g/Kg/day) for 2 weeks after the induction of diabetes by streptozotocin. At the end of the experiment, blood was collected from the abdominal aorta. A heparinized tube was used for collection of plasma for measurement of lipid peroxidation products, insulin, glucagon and fasting blood glucose. Pancreas were isolated and stained with hematoxylin and eosin (HE), histoimmunological and morphometric factors were studied. The results of this study showed that Propolis was able to reduce blood glucose significantly compared with the diabetic untreated group. Hypercellularity and density of B cells increased in pancreatic tissue, islets size and percent of B cells increased significantly in Propolis treated group which may signify regeneration of islets or B cells in Propolis treated rats. In the current study, we have demonstrated that, both structural and functional improvements of pancreas. Further researches are highly needed to clarify the specific molecular and cellular targets of various constituents of Propolis.

Evaluation of protective effects of hydroalcoholic extract of Cassia fistula Linn. Pod on pancreas in streptozotocin-induced diabetic rats

Background: Diabetes mellitus (DM) is associated with oxidative stress. Medicinal plants and herbs are the rich sources of antioxidants which ameliorate oxidative stress-induced diabetic complications and could play an important role in the management of diabetes. Objective: The present study aimed to evaluate the protective effects of 70% ethanolic extract of Cassia fistula pod on pancreas in streptozotocin (STZ)-induced diabetic rats. Materials and Methods: Diabetes was induced in male Wistar rats by single intraperitoneal injection of STZ (60 mg/kg b.wt.). The diabetic rats were administered orally with C. fistula pod extract at three different doses (100, 250, and 500 mg/kg b.wt./day) for 60 days. The results were compared with standard drug glibenclamide (5 mg/kg b.wt./day) treated rats. Relative pancreatic weight and serum insulin level were determined. Histopathological changes and oxidative stress parameters, i.e., lipid peroxidation (thiobarbituric acid reactive substance [TBARS]) and antioxidative defense markers (superoxide dismutase, catalase, glutathione, and ascorbic acid), in the pancreas were investigated. Results: Oral administration of C. fistula pod extract (100, 250, and 500 mg/kg b.wt./day) or glibenclamide in diabetic rats significantly improved serum insulin level, total protein concentration, relative pancreatic weight, and mean diameter of islets of Langerhans as compared to diabetic control rats. Furthermore, treatment with extract also reduced TBARS levels and improved the levels of antioxidant markers in the pancreas. The histomorphological picture of the pancreas showed marked restoration of islets morphology. These results were comparable with glibenclamide. Conclusions: The results of the present study showed that C. fistula pod extract possesses significant antidiabetic activity though enhanced insulin secretion, improvement of antioxidative status of pancreas, and preservation of the integrity of pancreatic islets. Abbreviations used: b.wt.: Body weight; CAT: Catalase; DM: Diabetes mellitus; DNA: Deoxyribonucleic acid; GSH: Glutathione; ROS: Reactive oxygen species; SOD: Superoxide dismutase; STZ: Streptozotocin; TBARS: Thiobarbituric acid reactive substances.

Evaluation of 4-methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid against hyperglycemia, insulin sensitivity, and oxidative stress-induced inflammatory responses and β-cell damage in the pancreas of streptozotocin-induced diabetic rats.

4-Methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid (bioactive compound (BAC)), a novel thiazole derivative, is a xanthine oxidase inhibitor and free radical scavenging agent. Effects of BAC on hyperglycemia, insulin sensitivity, oxidative stress, and inflammatory mediators were evaluated in streptozotocin (STZ)-induced neonatal models of non-insulin-dependent diabetes mellitus (NIDDM) rats where NIDDM was induced in neonatal pups with single intraperitoneal injection of STZ (100 mg/kg). The effect of BAC (10 and 20 mg/kg, p.o.) for 3 weeks was evaluated by the determination of blood glucose, oral glucose tolerance test (OGTT), HbA1c level, insulin level, insulin sensitivity, and insulin resistance (IR). Furthermore, inflammatory mediators (tumor necrosis factor-alpha and interleukin-6) and oxidative stress were estimated in serum and pancreatic tissue, respectively. Significant alteration in the level of blood glucose, OGTT, HbA1c, insulin level, insulin sensitivity, in addition variation in the antioxidant status and inflammatory mediators, and alteration in histoarchitecture of pancreatic tissue confirmed the potential of BAC in STZ-induced neonatal models of NIDDM rats. Pretreatment with BAC restored the level of glucose by decreasing the IR and increasing the insulin sensitivity. Furthermore, BAC balanced the antioxidant status and preserved the inflammatory mediators. Histological studies of pancreatic tissues showed normal architecture after BAC administration to diabetic rats. Altogether, our results suggest that BAC successfully reduces the blood glucose level and possesses antioxidant as well as anti-inflammatory activities. This leads to decreased histological damage in diabetic pancreatic tissues, suggesting the possibility of future diabetes treatments.

Allium hookeri root protects oxidative stress-induced inflammatory responses and β-cell damage in pancreas of streptozotocin-induced diabetic rats

BackgroundWater extract from the root of Allium hookeri (AH) shows anti-inflammatory, antioxidant, and free radical scavenging effects. In this study, the ameliorating effects of AH on oxidative stress-induced inflammatory response and β-cell damage in the pancreas of streptozotocin (STZ)-induced type 1 diabetic rats were investigated.MethodsAH (100 mg/kg body weight/day) was orally administered every day for 2 weeks to STZ-induced diabetic rats. After the final administration of AH, biochemical parameters including glucose, insulin, reactive oxygen species levels, and protein expressions related to antioxidant defense system in the pancreas of STZ-induced diabetic rats.ResultsThe diabetic rats showed loss of body weight and increased pancreatic weight, while the oral administration of AH attenuated body and pancreatic weight changes. Moreover, the administration of AH caused a slightly decrease in the serum glucose level and a significant increase in the serum and pancreatic insulin levels in the diabetic rats. AH also significantly reduced the enhanced levels of reactive oxygen species, oxidative stress biomarker, in the serum and pancreas. The diabetic rats exhibited a down-regulation of the protein expression related to antioxidant defense system in the pancreas, but AH administration significantly up-regulated the expression of the heme oxygenase-1 (HO-1). Furthermore, AH treatment was reduced the overexpression of nuclear factor-kappa B (NF-кB)p65 and NF-кBp65-induced inflammatory cytokines such as tumor necrosis factor-α and interleukin-6. In addition, AH treatment was less pancreatic β-cell damaged compared with those of the diabetic rats.ConclusionThese results provide important evidence that AH has a HO-1 activity on the oxidative stress conditions showing pancreato-protective effects against the development of inflammation in the diabetic rats. This study provides scientific evidence that AH protects the inflammatory responses by modulated NF-кBp65 signaling pathway through activation of HO-1 in the pancreas of STZ-induced diabetic rats.

Morphological study of the effects of aqueous leaf extract of Xylopia aethiopica on the pancreas in diabetic rats.

To investigate the histological and immunohistochemical effects of aqueous leaf extract of Xylo- pia aethiopica on the pancreas in streptozotocin-induced diabetic rats, 30 adult Wistar rats were divided into three groups (n=10). Group A was the control (administered with equivalent vol- ume of citrate buffer), group B animals were made diabetic by a single intraperitoneal injection of streptozotocin dissolved in citrate buffer (65 mg/kg), group C animals were made diabetic as above and treated with 200mg/kg body weight of aqueous leave extract of Xylopia aethiop- ica for 25 days. Upon animal sacrifice, the pancreas were excised, fixed in 10% formol saline and processed for light microscopy and immunohistochemistry.. The results revealed destruc- tion of the islet cells in the untreated diabetic group as compared with the controls. The extract treated group was characterized by recovery/regenerative processes indicated by improvement in islet morphology. In untreated diabetic rats immunoreactive P-cells were sparse, at variance from the controls. The group treated with aqueous leaf extract of Xylopia aethiopica revealed more intense staining for insulin and significant (p<0.05) increase in the percentage of immuno- labelled surface area when compared with the untreated diabetic group, suggesting the ability of P-cells to secrete insulin in the extract treated rats. We conclude that the aqueous leaf extract of Xylopia aethiopica improves recovery process of P-cells in streptozotocin-induced diabetic rats and might become useful in the management of diabetes related complications.

Opposite Expression of SPARC between the Liver and Pancreas in Streptozotocin-Induced Diabetic Rats.

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that regulates several cellular events, including inflammation and tissue remodelling. In this study, we investigated the tissue-specific expression of SPARC in streptozotocin (STZ)-induced diabetes, and found that SPARC was significantly up-regulated in the liver while down-regulated in the pancreas of STZ-induced diabetic rats. Chronic inflammation occurred in the diabetic pancreas accompanied by up-regulation of CCAAT/enhancer-binding protein beta (C/EBPβ) and its targets (TNFα, Il6, CRP, and Fn1) as well as myeloperoxidase (Mpo) and C-X-C chemokine receptor type 2 (Cxcr2). Diabetic liver showed significant up-regulation of Tgfb1 as well as moderately less up-regulated TNFα and reduced Fn1, resulting in elevated fibrogenesis. PARP-1 was not up-regulated during CD95-mediated apoptosis, resulting in restoration of high ATP levels in the diabetic liver. On the contrary, CD95-dependent apoptosis was not observed in the diabetic pancreas due to up-regulation of PARP-1 and ATP depletion, resulting in necrosis. The cytoprotective machinery was damaged by pancreatic inflammation, whereas adequate antioxidant capacity indicates low oxidative stress in the diabetic liver. High and low cellular insulin content was found in the diabetic liver and pancreas, respectively. Furthermore, we identified six novel interacting partner proteins of SPARC by co-immunoprecipitation in the diabetic liver and pancreas, and their interactions with SPARC were predicted by bioinformatics tools. Taken together, opposite expression of SPARC in the diabetic liver and pancreas may be related to inflammation and immune cell infiltration, degrees of apoptosis and fibrosis, cytoprotective machinery, and cellular insulin levels.

Magnetic resonance imaging of the pancreas in streptozotocin-induced diabetic rats: Gadofluorine P and Gd-DOTA.

To investigate the performance of Gadofluorine P-enhanced magnetic resonance imaging (MRI) on the diagnosis of diabetes in a streptozotocin (STZ) -induced diabetic rat model. Fischer 344 rats were treated with STZ. Rats not treated with STZ served as controls. T1-weighted MRI was performed using a 3T scanner before and after the injection of Gd-DOTA or Gadofluorine P (6 diabetic rats, 5 controls). The normalized signal intensity (SI) and the enhancement ratio (ER) of the pancreas were measured at each time point, and the values were compared between the normal and diabetic rats using the Mann-Whitney test. In addition, the values were correlated with the mean islet number. Optimal cut-off values were calculated using a positive test based on receiver operating characteristics. Intrapancreatic Gd concentration after the injection of each contrast media was measured using laser ablation-inductively coupled plasma-mass spectrometry in a separate set of rats (4 diabetic rats, 4 controls for Gadofluorine P; 2, 2 for Gd-DOTA). The normalized SI and ER of the pancreas using Gd-DOTA were not significantly different between diabetic rats and controls. With Gadofluorine P, the values were significantly higher in the diabetic rats than in the control rats 30 min after injection (P < 0.05). The area under the receiver operating characteristic curve that differentiated diabetic rats from the control group was greater for Gadofluorine P than for Gd-DOTA (0.967 vs 0.667, P = 0.085). An increase in normalized SI 30 min after Gadofluorine P was correlated with a decrease in the mean number of islets (r (2) = 0.510, P = 0.014). Intra-pancreatic Gd was higher in rats with Gadofluorine P injection than Gd-DOTA injection (Gadofluorine P vs Gd-DOTA, 7.37 vs 0.00, P < 0.01). A significant difference in the concentration of intrapancreatic Gd was observed between the control and diabetic animals that were sacrificed 30 min after Gadofluorine P injection (control vs diabetic, 3.25 ng/g vs 10.55 ng/g, P < 0.05) CONCLUSION: In this STZ-induced diabetes rat model, Gadofluorine P-enhanced MRI of the pancreas showed high accuracy in the diagnosis of diabetes.

Chrysin treatment improves diabetes and its complications in liver, brain, and pancreas in streptozotocin-induced diabetic rats.

Chrysin (CH) is a natural flavonoid with pharmacological influences. The purpose of the current study was the assessment of possible protective effects of CH against oxidative damage in the serum, liver, brain, and pancreas of streptozotocin (STZ)- induced diabetic rats. In the present study, the rats were divided into the following groups of 8 animals each: control, untreated diabetic, 3 CH (20, 40, 80 mg/kg/day)-treated diabetic groups. To find out the modulations of cellular antioxidant defense systems, malondialdehyde (MDA) level and antioxidant enzymes including glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities were determined in the serum, liver, brain, and pancreas. STZ caused an elevation of glucose, MDA, TG, TC, LDL-C and with reduction of HDL-C, total protein, SOD, CAT, and GST in the serum, liver, brain, and pancreas (p < 0.01). The findings showed that the significant elevation in the glucose, MDA, TG, TC, LDL-C and reduction of HDL-C, total protein, SOD, CAT, and GST were ameliorated in the CH-treated diabetic groups versus to the untreated groups, in a dose dependent manner (p < 0.05). The current study offers that CH may be recovered diabetes and its complications by modification of oxidative stress.

The Effect of Lupinus Albus and Hyphaene the Baica on Chromosomal Aberrations and Histopathological Changes of Liver and Pancreas in Streptozotocin-Induced Diabetic Rats

Background: The folk medicine in Egypt has described several kinds of Egyptian herbs and plant prescriptions, belonging to various families to be concerned with the treatment of diabetes mellitus.The present study focuses on evaluating the chromosomal aberration in somatic cells of STZ-diabetic rats treated with Lupinus albus (termis) and Hyphaene thebaica (doum) as well as their effect on liver and pancreas histopathology. Material and methods: STZ was injected intraperitoneally at a single dose of 50 mg/kg to induce diabetes. Termis seeds suspension (75 mg/100 g b.wt.) was daily orally administered, doum fruit suspension was daily orally administered (1g/kg b.wt.) and also gliclazide, reference drug, was administered at a dose equivalent to the therapeutic dose of rat. After four weeks of administration, bone-marrow metaphases were prepared for examining chromosomal aberration. These were followed by statistical analysis. Liver and pancreas were dissected, processed and stained with H&E for investigating histopathological changes. Results: The results of chromosomal analysis showed that, diabetic rats had a highly significant increase of chromosomal aberrations compared to that of normal healthy control. Animals which were treated with Lupinus albus and Hyphaene thebaica showed significant improvements in the frequencies of chromosomal aberrations. Also, treatment of diabetic rats with termis and doum revealed marked improvement in liver and pancreas histopathology. Conclusion: It is concluded that diabetes is much harmful on the histological picture of liver and pancreas and on chromosomal aberration frequencies in the animal body, whilst the administration of termis or doum reduced these harmful effects of diabetes.

Antihyperglycemic activities of methanolic leaf extract of Anacardium occidentale (Linn.) on the pancreas of streptozotocin-induced diabetic rats

Anacardium occidentale is a plant with reported antidiabetic and antioxidant properties. The stem, leave and bark extracts are known to contain saponin, phenolics, flavonoids, vitamins and selenium. Diabetes is a multisystemic disease characterised by defects in insulin secretion or inaction. In this study, forty male Wistar rats (Rattus norvegicus) were randomly divided into four experimental groups A, B, C and D. Hyperglycemia was induced by a single intraperitoneal injection of 70 mg/kg b.w streptozotocin (STZ). Hyperglycemia was confirmed 48 hours later. Five days after, the confirmation of hyperglycemia by using a glucometer (Roche (R) ) and compatible glucose test strips, Groups A and B were treated with 300 mg/kg b.w of A. occidentale extract (AOE) and 1 I U/kg b.w insulin, respectively. Groups C and D served as hyperglycemia and normal controls and received 1 ml/kg b.w citrate buffer, respectively. After 16 days of treatment the animals were sacrificed and the pancreas was processed for histological staining. Data obtained were expressed as means of ten (10) replicates ± SEM and subjected to one way analysis of variance (ANOVA) and the Scheffe’s post hoc test for multiple comparison. Findings showed that STZ-induced diabetes induced hyperglycemia and histopathological changes in the pancreas of untreated rats. Treatment with the methanolic extract of Anacardium occidentale resulted in reduction in hyperglycaemia and regeneration of beta cells.

β‐Casomorphin‐7 Cause Decreasing in Oxidative Stress and Inhibiting NF‐κB‐iNOS‐NO Signal Pathway in Pancreas of Diabetes Rats

β-Casomorphin-7 (β-CM-7) is a milk biological active peptide. The present study is aimed to investigate the protective effects of β-CM-7, against oxidative stress in pancreas of streptozotocin-induced diabetic rats by assaying malondialdehyde (MDA), nitric oxide (NO) level, the activity of enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), and NF-κB, inducible nitric oxide synthase (iNOS) gene expression. A significant increase in the level of oxidative stress was observed in pancreas of the diabetic rats when compared to control rats. After 15 d oral administration of β-CM-7 (7.5 × 10(-8) mol/d), the pancreas MDA level was markedly reduced. Oral administration of β-CM-7 to diabetic rats showed an obviously increase in the activity of catalase in pancreas, oral administration of β-CM-7 to the diabetic group of rats also showed a reduction of NF-κB and iNOS gene expression in pancreas. The elevated pancreas NO level was markedly reduced by the oral administration of β-CM-7. Thus, the results of the present study suggest that β-CM-7 may cause protective effects such as pronounced decreasing in oxidative stress and inhibiting NF-κB-iNOS-NO signal pathway in pancreas of diabetes rats.

Artemisia afraJacq. Ameliorates Oxidative Stress in the Pancreas of Streptozotocin-Induced Diabetic Wistar Rats

Diabetes is characterized by hyperglycemia resulting from defects in pancreatic insulin secretion and/or impaired target cell responsiveness to insulin, and Artemisia afra Jacq. is widely used in South Africa to treat the disease, but the mechanism of action is yet to be elucidated. This study explored the effect of oral administration of aqueous leaf extract of A. afra on the pancreas of streptozotocin-induced diabetic rats. We found that the extract significantly reduced blood glucose levels, accompanied by an increase in the serum insulin concentration. Moreover, the antioxidant enzymic activities of glutathione peroxidase, glutathione reductase, and superoxide dismutase also improved significantly after treatment with the extract. Increased pancreatic lipid peroxidation in the diabetic rats was also normalized by the extract. This study indicates that A. afra possesses hypoglycemic and antioxidant activities. Our findings suggest that the herb might exert its anti-diabetic activity by regenerating pancreatic beta cells, thereby stimulating the release of insulin.

Antioxidant protective effect of glibenclamide and metformin in combination with honey in pancreas of streptozotocin-induced diabetic rats.

Hyperglycemia exerts toxic effects on the pancreatic β-cells. This study investigated the hypothesis that the common antidiabetic drugs glibenclamide and metformin, in combination with tualang honey, offer additional protection for the pancreas of streptozotocin (STZ)-induced diabetic rats against oxidative stress and damage. Diabetes was induced in male Sprague Dawley rats by a single dose of STZ (60 mg/kg; ip). Diabetic rats had significantly elevated levels of lipid peroxidation (TBARS), up-regulated activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) while catalase (CAT) activity was significantly reduced. Glibenclamide and metformin produced no significant effects on TBARS and antioxidant enzymes except GPx in diabetic rats. In contrast, the combination of glibenclamide, metformin and honey significantly up-regulated CAT activity and down-regulated GPx activity while TBARS levels were significantly reduced. These findings suggest that tualang honey potentiates the effect of glibenclamide and metformin to protect diabetic rat pancreas against oxidative stress and damage.

Antioxidant and pancreas-protective effect of aucubin on rats with streptozotocin-induced diabetes

Oxidative stress has been suggested as a contributory factor in development and complication of diabetes. The aim of the present study was to determine the protective effect of aucubin on lipid peroxidation and activities of antioxidant defense systems and to conduct immunohistochemical evaluation of pancreas in streptozotocin-induced diabetic rats. Lipid peroxidation was determined by assessing the concentration of malondialdehyde and activities of antioxidant enzymes — catalase, glutathione peroxidase and superoxide dismutase in liver and kidneys of rats were determined. Changes of blood glucose and immunohistochemical evaluation on pancreas were also investigated as part of the pathology of diabetes. In our study, aucubin treatment lowered blood glucose. Diabetic rats exhibited an increase in the level of lipid peroxidation and decrease in activities of antioxidant enzymes in liver and kidneys as compared to control rats. Administration of aucubin to diabetic rats for 15 days significantly reversed damage associated with diabetes. In addition, diabetic rats showed an obvious decrease in insulin immunoreactivity and the number of β cells in pancreas, but the pancreas of aucubin-treated rats were improved and the number of immunoreactive β cells were significantly increased. These results indicated that aucubin may have value as a safe preventive or therapeutic agent against diabetes mellitus.

Protective effect of vanadyl sulfate on the pancreas of streptozotocin-induced diabetic rats

The aim of this study is to examine from a biochemical and histological perspective, whether vanadium has a protective effect on the pancreas of diabetic rats. Male, 6–6.5 months old, Swiss albino rats were divided into four groups. Group I: control (intact) animals ( n = 13). Group II: control rats given vanadyl sulfate ( n = 5). Group III: streptozotocin-induced diabetic animals ( n = 11). Group IV: streptozotocin-induced diabetic animals given vanadyl sulfate ( n = 11). Vanadyl sulfate was given by gavage technique to rats in a dose of 100 mg/kg daily for 60 days, after experimental animals were made diabetic. On day 60, the pancreas tissue and blood samples were taken from the animals. In the streptozotocin-induced diabetic group, blood glucose levels significantly increased in contrast to the loss of body weight, but vanadyl sulfate in streptozotocin-diabetic rats reduced blood glucose levels and increased both blood glutathione levels and body weight. Tissue sections were immunostained using an insulin antibody. The control group given vanadyl sulfate was no different from the other intact control group considering the insulin immunoreactivity in B cells. In pancreatic islets of the diabetic group, a decrease in the number of immunoreactive B cells was observed in comparison to the control group. On the other hand, pancreatic islets of the diabetic group given vanadyl sulfate showed a higher number of immunoreactive B cells in comparison to the diabetic group. According to the immunohistochemical and biochemical results obtained, it was concluded that vanadyl sulfate can regenerate B cells of endocrine pancreas in experimental diabetes.

Immunohistochemical localization of insulin in pancreatic beta-cells of taurine-supplemented or taurine-depleted diabetic rats.

The purpose of this study was to observe the effects of taurine supplementation or depletion on the immunohistochemical localization of insulin in pancreas of streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were fed for 7 weeks with a purified diet that was supplemented with 0, 1, 2 or 3% taurine in their drinking water. To induce taurine depletion, rats were treated with 5% beta-alanine in their drinking water. After 3 weeks, diabetes was induced by streptozotocin injection (50 mg/kg body-weight). The pancreatic tissue was stained immunocytochemically, using an antibody to insulin, and examined by light microscopy. The insulin levels in pancreatic beta-cells of the diabetic group that received no taurine-supplement were significantly decreased, compared to the non-diabetic group. The levels of insulin in beta-cell of 1% and 2% taurine-supplemented diabetic groups were significantly higher than those of the diabetic group, whereas the levels in the group receiving 3% taurine were not significantly different from that of non-diabetic rats. Therefore, it may be suggested that taurine protect pancreatic beta-cells against destruction by ptozotocin injection in a dose-dependent way.

A specific loss of c-series gangliosides in pancreas of streptozotocin-induced diabetic rats

Gangliosides in pancreas, kidney, and liver tissues from streptozotocin-induced diabetic rats were analyzed by methods including thin-layer Chromatographic (TLC) immunostaining with a specific monoclonal antibody to c-series gangliosides. In rats suffering diabetes for one month, the composition of major gangliosides in pancreatic tissue was almost identical to control, except for a slight increase in the content of GM3. Though c-series gangliosides such as GT3, GT2, GQ1c, and CP1c were expressed in normal pancreatic tissue, they were practically lost in pancreas of diabetic animals. A specific loss of c-series gangliosides was also observed in pancreatic tissue from rats suffering diabetes only for three days. While the composition of major gangliosides in the kidney did not change, streptozotocin-induced diabetic conditions brought about significant increases in contents of practically all major ganglioside species in liver tissue. No change was observed in the amount and composition of c-series gangliosides in both tissues. These results strongly suggest that c-series gangliosides are specifically localized in pancreatic B cells.

Chronic Effects of Camostate on Growth and Endocrine Function of the Pancreas in Streptozotocin-Induced Diabetic Rats

Chronic feeding of normal rats with camostate, a synthetic trypsin inhibitor, stimulates the growth of the pancreas chiefly by increasing cholecystokinin release. We examined the effects of camostate on the growth and the endocrine function of the pancreas in streptozotocin-induced diabetic rats. The pancreatic weight of the diabetic rats given camostate (200 mg/kg/day) by oral gavage for 14 days was significantly elevated by 120% over that of diabetic rats not given camostate, and was comparable to that in the nondiabetic rats given camostate. The total pancreatic contents of DNA, RNA, and protein in diabetic rats given camostate were also significantly higher than those in diabetic rats not given camostate, and did not differ from those observed in nondiabetic rats given camostate. The pancreatic growth seen in diabetic rats treated with camostate was associated with moderate hyperplasia and pronounced hypertrophy. By contrast, treatment with camostate did not improve hyperglycemia, hypoinsulinemia, or low pancreatic content of insulin seen in diabetic rats. These findings demonstrate a marked growth of the pancreas in diabetic rats stimulated by camostate, and suggest that camostate-induced pancreatic growth is not affected by the reduced level of the endogenous insulin. The present study also indicates that camostate has no beneficial effects on the function of residual B cells, failing to improve diabetes.

Histological and Microvascular Changes in the Parotid Gland and Pancreas of Streptozotocin-Induced Diabetic Rats

Histological and Microvascular Changes in the Parotid Gland and Pancreas of Streptozotocin-Induced Diabetic Rats