Purification of swine carbonic anhydrase isoenzymeIIIand measurement of its levels in tissues and plasma

Abstract

The changes in the levels of carbonic anhydrase isozyme III (CA-III) in swine plasma and urine have not been previously determined or reported. CA-III is relatively specific to skeletal muscles, and should therefore be a useful diagnostic marker for muscle diseases. We isolated CA-III from swine muscle tissues and determined CA-III levels in the plasma and urine from both healthy and diseased pigs. The levels of CA-III in the tissues of female swine (age, 3months) and plasma of young swine (age, 1-5months) and adult female pigs (age, 2-3years) were determined using the ELISA system for swine CA-III. The mean (±SD) levels of CA-III in the skeletal muscles were 3.8±3.2mg/g (wet tissue), and in the plasma, 230±193ng/ml at 1month, 189±208ng/ml at 2months, 141±148ng/ml at 3months, 78±142ng/ml at 4months and 53±99ng/ml at 5months. The mean level of CA-III in the plasma samples from 2- to 3-year-old pigs was 18±60ng/ml. CA-III in the plasma samples was found to decrease from 1month until 3years of age (p<0.01). We performed far-western blotting to clarify the cause of the observed decrease in CA-III in plasma. Our results demonstrated that CA-III is bound to the transferrin and albumin. In addition, we determined that the levels of CA-III in plasma and urine samples were higher in diseased swine compared with the healthy pigs.