Insulin resistance/beta-cell function and serum ferritin level in non-diabetic patients with hepatitis C virus infection.

Background/aims: Since impaired glucose tolerance and iron overload are frequently demonstrated in hepatitis C virus (HCV)-related liver diseases, in this study we investigated insulin resistance, pancreatic beta-cell function, i.e., insulin secretion, and serum ferritin levels in patients with HCV infection, especially non-diabetic patients.

Effects of nitric oxide on the redox status of liver microsomes-electron spin resonance monitoring using nitroxide probes.

Nitroxide radicals (nitroxides) are reduced to the corresponding hydroxylamines and lose their electron spin resonance (ESR) signals, but these hydroxylamines are easily reoxidized to nitroxides and regain the ESR signals. In the present study the effects of nitric oxide (NO) on the reduction/oxidation (redox) status of hepatic microsomes were investigated by ESR spectroscopy using nitroxide probes. Rat hepatic microsomes were treated with an NO donor, NOR3 or NOC7, and then labeled with a water-soluble nitroxide, 2,2,6,6-tetramethyl-4-hydroxy-1-piperidinyloxy (Tempol), or a lipid-soluble nitroxide, 5-doxyl stearic acid (5-DSA).

Elevation of serum thioredoxin levels in patients with type 2 diabetes.

To evaluate the clinical significance of thioredoxin in diabetic patients, serum thioredoxin levels measured with a recently established sandwich enzyme-linked immunosorbent assay kit were compared with clinical laboratory data and complications in 174 patients with Type 2 diabetes. Thioredoxin levels were significantly higher in diabetic patients (mean value, 38 ng/ml) than in healthy controls (21 ng/ml) (p < 0.05).

Increase in glucose-stimulated insulin release and insulin biosynthesis in isolated pancreatic islets from D-galactosamine-treated rats.

Insulin secretion in response to glucose, glucose-stimulated insulin biosynthesis and insulin content was studied in pancreatic islets freshly isolated from male Wistar rats (150-200 g) with galactosamine-induced hepatitis. Animals were sacrificed by decapitation 3, 6, 12 and 24 hours after a single intraperitoneal injection of 500 mg/kg of galactosamine. Isolated islets prepared by collagenase method were perifused in Swim's medium with 20 mM glucose at 37 degrees C up to 30 minutes.

Concentrated loss of insulin secretion in Wistar rats with normal glucose tolerance.

Rats with decreased insulin response and with normal glucose tolerance were concentrated by repeated selective breeding of normal Wistar rats with low insulinogenic index. In general, the mean insulinogenic index of the inbred offsprings showed a tendency to decrease more than their parents generation. Thus mean insulinogenic indices in second (F2), third (F3) and fourth (F4) generations were significantly reduced more than the normal rats without glucose intolerance.