Anemia carbonic anhydrase

From a nutritional viewpoint, Cu2+ competes with zinc ion, as does the very toxic Cd2+. The latter accumulates in the cortex of the kidney. Dietary cadmium in concentrations less than those found in human kidneys shortens the lives of rats and mice. However, some marine diatoms contain a cadmium-dependent carbonic anhydrase.11 Although zinc deficiency was once regarded as unlikely in humans, it is now recognized as occurring mider a variety of circumstances0 p and is well-known in domestic animals.01 Consumption of excessive amounts of protein as well as alcoholism, malabsorption, sickle cell anemia, and chronic kidney disease can all be accompanied by zinc deficiency. 

Zn Zn2+ 16 mg Over 200 e.g., carbonic anhydrase, carboxypeptidases Sickle cell anemia causes a Zn deficiency... 

Aplastic anemia occurs in about one in 18 000 patient-years of exposure to oral carbonic anhydrase inhibitors. Most cases occur within the first 6 months, and peak at 2-3 months. 

Zinc is an essential trace element and is commonly ingested as a nutritional supplement. Divalent zinc is one of the most important of the micronutrients. More than 100 enzymes are zinc dependent for example, carboxypeptidase, carbonic anhydrase (which is responsible for the exchange of carbonic acid in the blood and the exhalation of carbon dioxide), and the alcohol dehydrogenase (which metabolizes alcohol). Deficiency of zinc, especially in newborns, results in impaired growth, loss of hair, skin eruptions, and often impaired or delayed sexual maturation. Many medical problems are also associated with zinc deficiencies (e.g., ulcerative colitis, chronic renal disease, and anemia). 

Carbonic anhydrase inhibitors can cause fluid and electrolyte imbalance, metabolic acidosis, nausea, vomiting, anorexia, confusion, orthostatic hypotension, and crystaUuria. Hemol5dic anemia and renal calculi can also occur. Carbonic anhydrase inhibitors are contraindicated in the first trimester of pregnancy. 

The whole of the zinc in erythrocytes can be accounted for as carbonic anhydrase, and the carbonic anhydrase activity of blood is confined to the erythrocytes. There is none in the plasma or leucocytes. This sug-gests.that the carbonic anhydrase activity of blood might be low in anemia and high in polycythemia and that zinc determinations might provide a useful means of estimating the amount of the enzyme in red blood cells. Both these points have been convincingly answered by Vallee and his associates. They have shown that in almost all patients with anemias,... 

Fig. 2. The relationship of zinc in micrograms per cubic centimeter of erythrocytes to carbonic anhydrase in U units per cubic centimeter of erythrocytes in anemias other than pernicious anemia. The rectangle denotes the normal range. The line connecting with the zero point is drawn through the normal mean of both parameters.

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