Decreased total carbonic anhydrase esterase activity and decreased levels of carbonic anhydrase 1 isozyme in erythrocytes of type II diabetic patients

Abstract

In this exploratory study, we investigated total erythrocyte carbonic anhydrase (CA) estrase activity as well as CA I isozyme concentration in patients with diabetes mellitus type II (DM) and healthy individuals of Howard University Hospital community. Total estrase activity of CA was measured spectrophotometrically using p-nitrophenol acetate before and after inhibition with acetazolamide. CA I isozyme was measured by radial immunodiffusion using monoclonal antibody (CA I) in agarose plates. The study involved 20 consented participants; 10 normal (N) and 10 (DM), 21 to 84 years of age. The study was approved by the Howard University Institution Review Board. The CA activity was measured following lysis of cells as U/min/mL and CA I concentration as mg/l. We observed CA activity as 46.3+/-4(N) and 25+/-2.1 (DM) whereas CA I concentration as 1896+/-125 (N) and 1104 +/-63 (DM). We speculate that the change in the CA activity may of fundamental importance in the regulation of intracellular; pH(i) for the basic control of metabolism in diabetes mellitus. Further, we propose that CA activity is a good candidate for a biomarker of diabetes mellitus for the early detection of insulin resistance because the CA activity variation was proportional to the severity of the diabetes.

Interactive effects of salinity and elevated CO2 levels on juvenile eastern oysters,Crassostrea virginica

“…CA activity was determined as acetazolamide (AZM)-sensitive esterase activity following a standard method modified from Gambhir et al (Gambhir et al, 2007). The assay consisted of 100l of tissue homogenate in 1ml of assay medium containing 63mmoll -1…”

“…After determining the initial slope of esterase reaction, a specific CA inhibitor, AZM (7mmoll -1 ), was added to the assay, and CA activity was determined as the difference in the initial reaction slopes before and after AZM addition using the molar extinction coefficient for p-nitrophenol of 5lmmol (Nielsen and Frieden, 1972;Smeda and Houston, 1979;Gambhir et al, 2007;Malheiro et al, 2009). CA activity determined with the AZM-sensitive esterase assay correlates with the cellular CA content (Gambhir et al, 2007). Protein concentration was measured in tissue homogenates of juvenile oysters using the Bio-Rad protein assay (Bio-Rad Laboratories, Hercules, CA, USA) using bovine serum albumin as a standard.…”

Erythrocyte Total Carbonic Anhydrase Esterase Activity in African American Obese Children: Reduction Starts at a Young Age

“…It is possible that CA activity may increase, then slowly return to normal and subsequently decrease through the steps of diabetes. Previous studies have shown that adult individuals with type 2 diabetes have significantly lower CA activity than normal individuals (Gambhir et al 2007).…”

“…Furthermore, the values varied with the severity of the diabetes or insulin resistance (Gambhir et al 2007). Kondo et al (1975) reported contradictory results, however, as they found increased levels of both CAI and CAII in patients with diabetes.…”

Inhibition of Carbonic Anhydrase Results in Blood Lactate Accumulation (BLA) in STZ Induced Diabetic Rats

“…Gambhir et al [21] observed decrease in carbonic anhydrase activity in type II diabetic patients when compared with Normal subjects. They therefore speculate that the change in the CA activity may be of fundamental importance in the regulation of intracellular; pH for the basic control of metabolism in diabetes mellitus.…”