Islet transplantation has the potential to restore normoglycemia and prevent the development of diabetic complications such as retinopathy, nephropathy and neuropathy, and could therefore ve a valuable treatment for diabetic patients. The scarcity of available islets is an obstacle for clinically successful islet transplantation. To resolve the problems, we have examined the two methods, islet transplantation with extracellular matrix1 and in vivo expansion of islets with electrically- transfection of growth factors.
Animals ; Diabetes Mellitus/surgery/*therapy ; Fibronectins/therapeutic use ; Hepatocyte Growth Factor/genetics ; Islets of Langerhans/drug effects/*physiopathology ; *Islets of Langerhans Transplantation ; Male ; Rats ; Rats, Wistar ; *Regeneration ; Transfection

In this study, the rat type 2 diabetes mellitus (T2DM) model was established through tail vein injection with low dose of streptozotocin (STZ) and high fat diet for 8 weeks, and then treated with Jiaotai Pill. The oral glucose tolerance test (OGTT), fasting serum insulin (FINS), free fatty acid(FFA) levels and blood lipid were assayed. HOMA-IR was calculated. Pancreatic pathology was performed. And pancreatic triglyceride (TG) content was examined by the lipid extraction method. Pancreatic islet cell apoptosis were detected by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). According to the results, the model group showed abnormal OGTT, increased FINS, HOMA-IR, FFA, lipid disorder, obvious fat accumulation and significantly increased TG content in pancreatic tissues, and enhanced pancreatic islet cell apoptosis. Compared with the model group, the Jiaotai Pill group displayed improved OGTT, reduced FINS, HOMA-IR, FFA, recovered lipid disorder, decreased fat accumulation and significantly declined TG content in pancreatic tissues, and lowered pancreatic islet cell apoptosis. In summary, Jiaotai pill could effectively treat type 2 diabetes in rats. Its mechanism may be related to the reduction in pancreatic fat accumulation and islet cell apoptosis.
Animals ; Apoptosis ; drug effects ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; physiopathology ; Drugs, Chinese Herbal ; administration & dosage ; Fats ; metabolism ; Glucose Tolerance Test ; Humans ; Islets of Langerhans ; cytology ; drug effects ; Male ; Pancreas ; drug effects ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the effect of N-acetyl-l-cysteine (NAC) on islet beta cell function in hyperlipidemic rats and its mechanism.

METHODSFifty-nine male SD rats of 8 week old were randomly divided into 3 groups: normal diet group(NC, n=20), high fat diet group (HF, n=20) and NAC treated group (NAC, n=19, NAC 300 mg x kg(-1) x d(-1) and high fat diet). At the end of 20 weeks, fasting serum insulin (Ins), glucose(Glu), malonaldehyde (MDA) and reduced glutathione (GSH) were determined in plasma and pancreas tissue. The glucose infusion rate (GIR) was measured by euglycemic hyperinsulinemia clamp to evaluate the peripheral insulin resistance.Pancreatic islets were isolated and subjected to a perifusion medium containing 3.3 mmol/L glucose for 15 min, followed by 16.7 mmol/L glucose for 30 min, insulin content of perifusion medium was measured by RIA. The expressions of IRS-1, IRS-2, Glut-2 gene in islets were detected by real time PCR.

RESULTS(1)The insulin, glucose and MDA concentration in HF group were higher than those in NC group, but GSH levels in plasma and pancreas were lower. NAC intervention could reverse these effects. (2)The GIR was decreased significantly in HF group compared with NC group [(5.25 +/-1.2) Compared with (13.56 +/-1.7) mg x min(-1) x kg(-1), P<0.01], NAC intervention reversed these effect: GIR[(9.28 +/-1.50) Compared with (5.25 +/-1.2)mg x min(-1) x kg(-1), P<0.01]. (3) 16.7 mmol/L glucose increased the insulin secretion in the islet cells of the three groups, but the peak was lower in HF group. NAC intervention reversed these effects. (4) The gene expression of IRS-1 was significantly decreased by 42.3 % in HF group (P<0.05), and the expressions of IRS-2 and Glut-2 were decreased by 28.1% and 22.9% (P<0.05) compared with NC group. In contrast, the expressions of IRS-1, IRS-2, Glut-2 in NAC group increased by 40.2%, 30.2% and 19.1%, respectively than those in HF group.

CONCLUSIONNAC can reverse functional disorder of islet beta cells induced by high-fat-diet feeding. This antioxidant effect might be associated with upgrading gene expression of insulin signal transduction molecules in islet beta cells.

Acetylcysteine ; pharmacology ; Animals ; Dietary Fats ; administration & dosage ; Free Radical Scavengers ; pharmacology ; Hyperlipidemias ; metabolism ; physiopathology ; Insulin Resistance ; Islets of Langerhans ; drug effects ; secretion ; Male ; Oxidative Stress ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

OBJECTIVETo investigate the effect and mechanism of Tangyikang (TYK) for improving pancreatic islet beta cell function in patients with latent autoimmune diabetes mellitus in adults (LADA).

METHODSSeventy-four LADA patients were randomly assigned to two groups. The 37 patients in the treatment group were treated with TYK decoction (one dose consisted of red ginseng 10 g, milkvetch root 30 g, lilyturf root 15 g, wild weed 10 g, coptis root 15 g, cape-jasmine fruit 10 g, giant knotweed rhizome 10 g, safflower 10 g and moutan bark 10 g) combined with insulin therapy, and the 37 in the control group treated with insulin therapy alone, and the course for all was 3 months. Changes of glycosylated hemoglobin, index of pancreatic islet beta-cell function (delta CP(2h)/delta BS(2h)), serum interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were observed before and after treatment.

RESULTSAll the above-mentioned indexes were improved after treatment in both groups, the post-treatment data showed significant difference between groups in delta CP(2h)/delta BS(2h), (0.258 +/- 0.106 vs 0.168 +/- 0.054, higher in the treatment group, t = 4.626, P < 0.01), but with insignificant difference in glycosylated hemoglobin (t = 0.441, P = 0.660). Besides, the dosage of insulin used in the treatment group was less than that in the control group (t = -4.169, P < 0.01); covariance analysis showed, through excluding impact of different dosages insulin used, IL- 4 level was higher (F = 24.217, P < 0.01) and IFN-gamma level was lower (F = 14.198, P < 0.01) in the treatment group than those in the control group.

CONCLUSIONSTYK could improve the function of islet beta-cell, its possible mechanism is related with the regulation on cell immunity and the correction of T-lymphocyte subsets (Th1/Th2 ratio) imbalance.

Adult ; Diabetes Mellitus, Type 1 ; blood ; drug therapy ; immunology ; physiopathology ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Humans ; Interferon-gamma ; blood ; Interleukin-4 ; blood ; Islets of Langerhans ; drug effects ; immunology ; physiopathology ; Male ; Middle Aged ; Young Adult