Comparative in vitro uptake of zinc by erythrocytes of normal vs Type 2 diabetic individuals and the associated factors.
Diabetes is an oxidative stress-related disorder in which erythrocyte zinc uptake may vary as compared to healthy individuals. Since zinc is one of the important antioxidant trace metals, some functional indices of erythrocyte zinc status, ie in vitro zinc uptake, osmotic fragility and glucose uptake, were compared in Type 2 diabetic subjects (n=43) and healthy controls (n=22). The associations of these indices with plasma levels of antioxidants and micronutrients were examined. The trace metals were analyzed by atomic absorption spectrophotometer. Vitamins were estimated using spectrophotometric and spectroflourometric methods. In vitro zinc uptakes of healthy subjects were 17 to 52% higher (p<0.01) than those for diabetic subjects. The osmotic fragility for diabetic cells was 2.2 to 1.5 times higher than the healthy cells in 0.85-0.5% NaCl solutions (p<0.05). Percent hemolysis at 0.75, 0.65 and 0.55% NaCl had significant negative correlations (p<0.05) with in vitro zinc uptakes and that at 0.50% NaCl had a positive correlation with HbA1c levels (p<0.05). The in vitro zinc uptakes of erythrocytes in healthy subjects showed a strong negative correlation (p<0.01) with percent hemolysis at 0.75, 0.65 and 0.55% NaCl, a positive correlation with plasma zinc (r=0.33, p<0.05) and a strong negative correlation with plasma selenium and iron, hemoglobin and serum ceruloplasmin indicating antagonistic behavior of copper, iron and selenium with zinc uptake (p<0.01). Furthermore, erythrocyte super oxide dismutase (SOD), plasma ascorbic acid and status of riboflavin and thiamine were negatively correlated with in vitro zinc uptakes of erythrocytes in healthy subjects (p<0.01). These associations in the diabetic subjects were weaker than normal. Erythrocyte zinc uptake and osmotic fragility could be biomarkers of long-term zinc status and decrease of zinc uptake may be one of the features of diabetic patients.
Agte
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Agharkar Research Institute, Pune, India. vaishaliagte@hotmail.com
Nagmote
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Tarwadi
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KV
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000032:analysis; D001205:Ascorbic Acid / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002570:Ceruloplasmin / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D006801:Humans; D066298:In Vitro Techniques; D007501:Iron / Q000097:blood; D008297:Male; D008670:Metals / Q000097:blood; D018977:Micronutrients / Q000097:blood; D008875:Middle Aged; D009996:Osmotic Fragility; D018384:Oxidative Stress; D012256:Riboflavin / Q000097:blood; D012643:Selenium / Q000097:blood; D012965:Sodium Chloride; D013050:Spectrometry, Fluorescence; D013054:Spectrophotometry, Atomic; D013482:Superoxide Dismutase / Q000097:blood; D013831:Thiamine / Q000097:blood; D014815:Vitamins / Q000097:blood; D015032:Zinc / Q000097:blood*
D000975:Antioxidants; D001205:Ascorbic Acid; D001786:Blood Glucose; D002570:Ceruloplasmin; D006442:Glycated Hemoglobin; D006454:Hemoglobins; D007501:Iron; D008670:Metals; D018977:Micronutrients; D012256:Riboflavin; D012643:Selenium; D012965:Sodium Chloride; D013482:Superoxide Dismutase; D013831:Thiamine; D014815:Vitamins; D015032:Zinc