Antioxidant status, oxidative stress and DNA damage in the aetiology of malnutrition related diabetes mellitus

Diabetes in rural individuals of different nutritional status and the alarming situation demands focus more on its under-nutrition association

OBJECTIVE

To study the relationship of nutritional-status with diabetes.

DESIGN

The socioeconomics/anthropometrics, blood-glucose/systemic-hypertension are evaluated in consecutively-selected diabetic-patients.

SETTING

Semi-urban/rural India.

SUBJECTS

Hyperglycaemic patients (total 90/male 37).

RESULTS

Blood-glucose (PP-mean ± SE) in individuals is overweight - 38.89% (226.94 ± 9.59), normal-weight - 50% (217.58 ± 1.34), underweight - 11.11% (305.50 ± 21.35) indicating most hyperglycaemia in undernourished-group (F = 6.357, p < 0.003). This group occupies higher glucose-groups in ≤140, 141-270, and ≥270 mg/dL. The blood-glucose negatively correlates with waist(r = -0.282; p < 0.01) and hip (r = -0.254; p < 0.05) circumference indicating the under-nutrition association with glucose-homeostasis (F = 7.6-8.2, p < 0.001). The higher glucose is noticed in more number of individuals in lower (<40 years) age-group (χ(2 )= 12.86; p < 0.002/ρ = -0.355; p < 0.001). The prevalence of hypertension is 28% (underweight = 20%, overweight = 27%, normal = 30%). The group of 141-270 mg/dL glucose has 45% and rest groups together have 23% hypertensive individuals relating directly, hypertension and diabetic-onset.

CONCLUSIONS

Diabetes, explored in <40 years group and even more in female should be extensively studied accounting WHO categorization (1985/TRS/727) of malnutrition related diabetes (MRDM). Further, different interactive risk-factors should be properly addressed and the global-malnutrition/gender-based inequities be eradicated.

A dicopper complex chemiluminescence probe for the determination of thiols in the extracts of murine P388 lymphocytic leukemia cell

A chemiluminescence (CL) probe of peroxidase-like dicopper complex (Cu2L2) for the determination of glutathione (GSH) and related cellular thiols was developed for the first time.

Development of an amperometric biosensor based on glutathione peroxidase immobilized in a carbodiimide matrix for the analysis of reduced glutathione from serum

The development of an amperometric biosensor for the reduced glutathione determination in serum is described. The biosensor is based on glutathione peroxidase (GSH-Px, EC 1.11.1.9) immobilized onto a pyrolytic graphite-working electrode using carbodiimide as enzymatic condensing reagent. This resulted in an amperometric biosensor with good sensitivity and stability. The reduced glutathione (GSH) was enzymatically converted to glutathione disulfide (GSSG) in the presence of hydroperoxide, which was monitored amperometrically by its electrooxidation at +0.65 V vs. SCE (saturated calomel electrode). Glutathione measurement was carried out by maintaining the ratio between GSH and hydrogen peroxide at 2:1 (25 degrees C). The amperometric response of the biosensor was linearly proportional to the GSH concentration between 1.9x10(-5) and 1.4x10(-4) mol/l, in 0.1 mol/l phosphate buffer (pH=7.8), containing 0.1 mol/l KCl and 0.5 mmol/l Na(2)H(2)EDTA, as the supporting electrolyte. In presence of interfering compounds, the recoveries ranged between 97.2% and 110.7%. The biosensor useful lifetime was at least 2 months when it was evaluated after continuous use. Serum samples analyzed by this biosensor showed a good correlation with the results from the spectrophotometric method (Ellman's reagent) used as reference, presenting relative deviations lower than 7.0%. The low apparent Michaelis-Menten constant value, K(M)(app)=1.6 mmol/l, demonstrated that GSH-Px immobilized on pyrolytic graphite exhibited a high affinity to GSH, without loss of enzymatic activity.

Effect of retinoic acid on glucokinase activity and gene expression and on insulin secretion in primary cultures of pancreatic islets

Retinoic acid has manifold effects on pancreatic beta-cells. Previously we reported that retinoic acid increases glucokinase activity and messenger RNA (mRNA) levels in the insulinoma cell line RIN-m5F; however, we could not rule out the possibility that the effect of retinoic acid on RIN-m5F glucokinase was inherent to the cell line or related to its differentiating capacity. In this report, we demonstrate that physiologic concentrations of retinoic acid stimulate glucokinase activity in both fetal islets and differentiated adult islets in culture. In the adult tissue, the response to the retinoid was less pronounced, achieving about half of the maximal effect produced on the fetal tissue. Using the branched DNA (bDNA) assay, a sensitive signal amplification technique, we detected relative increases in glucokinase mRNA levels of 51.8+/-13.3% and 62.8+/-16.1% at 12 and 24 h, respectively, in adult islets treated with] 10(-6) M retinoic acid. In fetal islets, increases of 55+/-14.9% and 107+/-30.5% at 12 and 24 h, respectively, were observed. In transfected fetal islets, retinoic acid increased the activity of the -1000 kb rat glucokinase promoter by 51.3%. Because glucokinase activity controls insulin secretion, we also investigated the effect of retinoic acid on insulin secretion. Treatment with 10(-6) M retinoic acid for 24 h increased insulin secretion in both fetal and adult islets; however, the increases on insulin secretion were more pronounced in the mature islets; in contrast, retinoic acid produced higher levels of insulin mRNA in the fetal islets. These data show that retinoic acid increases pancreatic glucokinase in cultured islets and that the mechanism may involve a stimulatory effect on the glucokinase promoter.