Changes in erythrocyte ATPase activity under different pathological conditions

Background: Studies have shown that Na+-K+ ATPase activity was altered in disrupted red blood cell membranes and this enzyme is believed to be the site of active transport of Na+ and K+ in intact red blood cells. The enzyme is often referred to as Na+- K+ pump because it pumps Na+ out and K+ into the cell against gradients with the concomitant hydrolysis of intracellular ATP.Objective: The aim of this study was to find out the possibility of using Na+-K+-ATPase activity as a biomarker for the diagnosis of individuals with different physiological conditions.Materials and methods: The activity of Na+-K+ ATPase was determined in blood samples collected from different pathological and physiological conditions such as pregnancy, smoking, diabetes and renal dysfunction compared with healthy subjects matched for age and sex.Results: The Na+-K+ ATPase activity in pregnancy (0.094 ± 0.0051 μM Pi/min. mg protein), smoking (0.064 ± 0.0011 μM), diabetes (0.047 μM 0.002 μM) and kidney disease (0.069 ± 0.0014 μM) was higher compared to the measurements in healthy individuals (0.0081 ± 0.0031 μM).Conclusion: Na+- K+ATPase specific activity is a biomarker for the diagnosis of individuals with different physiological diseases.Keywords: Na+-K+ATPase, red blood cell, pregnancy, smoking, diabetes, kidney diseases

Analysis of SNPs of MC4R , GNB3 and FTO gene polymorphism in obese Saudi subjects

Background: The goal of this study was to analyze the association between the FTO rs17817449 (G>T), G protein beta3 subunit (GNB3) C825T and Melanocortin 4 receptor (MC4R) A822G single nucleotide  olymorphism (SNP) with obesity in Saudi subjects.Methods: The subjects were divided into 2 groups according to BMI: Obese (BMI> 29.9) and non- obese control (BMI<24.9). Genotyping of the target genes were determined by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism analysis (RFLP).Results: We demonstrated the association of the FTO genotype TT with increased weight, BMI and leptin levels in both males and females. However, there was no association of genotype TT with fasting blood glucose, triglycerides and cholesterol levels. Regarding GNB3 rs5443 polymorphism, the likelihood of obesity was linked to the TT genotype which was also associated with increased leptin levels. On the other hand, the SNP of MC4R A822G did not exhibit any significant association with obesity among studied subjects and showed only the presence of homozygous AA genotype.Conclusion: The polymorphism of FTO gene rs17817449 and GNB3 gene rs5443 (C825T) may be a genetic determinant of obesity in Saudi population whereas impact of MC4R Asn274Ser change could not be detected.Keywords: Obesity, FTO gene-polymorphism

Serum resistin, adiposity and insulin resistance in Saudi women with type 2 diabetes mellitus.

BACKGROUND : The role of adipocyte hormones in modulating insulin sensitivity and glucose tolerance are of increasing interest and importance in studies of type 2 diabetes mellitus. Recently a unique signaling molecule, resistin, has been proposed as playing a role in the pathogenesis of obesity-related insulin resistance, but its relevance to human diabetes remains uncertain. Therefore, we assessed the relationship between serum resistin concentrations and insulin resistance in lean, overweight and obese (OW/OB) non-diabetic and diabetic Saudi women. SUBJECTS AND METHODS : We measured fasting serum resistin levels in 44 diabetic women with a mean body mass index (BMI) of 31.82±4.35 kg/m2, 21 OW/OB non-diabetic women with a mean BMI 30.71±3.42 kg/m2 and in 24 lean women with a mean BMI of 23.33±1.24 kg/m2. Insulin resistance was assessed using the homeostasis model assessment for insulin resistance formula derived from fasting insulin and glucose levels. RESULTS : The concentrations of fasting serum resistin showed significant differences among the three groups (P< 0.001). Mean serum resistin concentrations increased from lean (11.59± 2.08) to OW/OB non-diabetic (16.29±2.29) to diabetic (19.42±3.60 ng/mL) women. Significantly higher levels of glucose (P< 0.001) and values for the homeostasis model assessment ratio (HOMA-R) (P< 0.01) occurred in the diabetic compared to the lean and OW/OB non-diabetic subjects. Furthermore, resistin correlated significantly and positively with hip circumferences (r=0.39, P=0.039), weight (r=0.51, P=0.005), insulin (r=0.40, P=0.033), HOMA-R (r=0.49, P=0.007) and glucose (r=0.39, P=0.038) in diabetic women. In OW/OB non-diabetic subjects, resistin correlated with insulin (r=0.59, P=0.015) and HOMA-R (r=0.616, P=0.011). No correlation was observed with glucose, height, hip, waist, weight, and waist-hip ratio (WHR) in the lean and OW/OB non-diabetic groups. CONCLUSION : Resistin concentrations are elevated in patients with type 2 diabetes and are associated with obesity and insulin resistance. These data indicate that resistin might be involved in the development of diabetes in humans