CARBONIC ANHYDRASE ACTIVITY AND ZINC DEFICIENCY

Abstract

A 60-year-old female was hospitalized because of anemia, edema, and diarrhea. She was diagnosed as having short bowel syndrome. The patient developed acrodermatitis enteropathica and taste impairment. Laboratory data showed that the serum zinc level was 21 μ g/dl and erythrocyte CAI specific activity was 0 units/mg isozyme (normal range 0.37 ± 0.08 units/mg isozyme) and CAII specific activity was 2.99 units/mg isozyme (normal range 3.02 ± 0.05 units/mg isozyme). The patient was diagnosed as being in a zinc deficient status. Zinc supplementation resulted in the disappearance of these complications. The serum zinc level reached 50 μ g/dl and erythrocyte CAI specific activity was recovered to 0.26 units/mg isozyme and CAII specific activity was 1.60 units/mg isozyme. CAI is found in gastrointestinal epithelial cells, in vascular epithelium, corneal, lens, ciliary body epithelium, and in sweat glands. CAII is found in virtually all tissues and is especially abundant in secretory and absorbing epithelia. The tissue distribution of CAI corresponds to clinical and physiologic indicators of zinc deficiency. Thus, the erythrocyte CAI specific activity may reflect the actual tissue zinc deficiency status.