Levels Of Carbonic Anhydrase Research Articles

Carbonic anhydrase levels in chlamydomonas

Levels of carbonic anhydrase in Chlamydomonas reindhardtii were 20-fold higher on both a protein and chlorophyll basis when algae were grown on 0·03 per cent CO 2 as compared to algae grown on 1 per cent CO 2. This result suggests a functional role for carbonic anhydrase in photosynthesis.

CARBONIC ANHYDRASE IN THE PREMATURE

Carbonic anhydrase activity was measured in the blood of premature and full-term infants to determine if the arterial-alveolar carbon dioxide gradient was related to low levels of carbonic anhydrase. The time at which levels in these infants approached the adult was studied as well. The study demonstrates that CO2 gradients do not correlate with blood carbonic anhydrase activity, and minimal or no activity can be associated with a small gradient. An increase in the carbonic anhydrase activity-produced by transfusion did not significantly change the CO2 gradient. Premature infants approach adult levels of activity in 6 to 7 months.

Distribution of carbonic anhydrase in relation to the C 4 pathway of photosynthesis

The level of carbonic anhydrase in leaves of species which fix CO 2 via the C 4-dicarboxylic acid pathway of photosynthesis is one-fifth to one-tenth that in species in which the normal Calvin cycle is operative. Analysis of non-aqueous fractions of leaves indicates that carbonic anhydrase is a cytoplasmic enzyme in plants with C 4-dicarboxylic acid pathway, whereas in plants with only the Calvin cycle the enzyme is located in the chloroplasts.

Haemoglobin and red cell enzyme changes in juvenile myeloid leukaemia.

The switchover from foetal to adult haemoglobin synthesis, which is normaly complete by the end of the first year of life, is accompanied by marked changes in the red cell enzyme pattern. In particular, the level of carbonic anhydrase, which is very low in cord blood, rapidly increases during the first year of life to become the most abundant of the red cell non haemoglobin proteins. There have been occasional reports of the presence of increased levels of foetal haemoglobin in the red cells of patients with leukaemia (Beaven et al., 1960; Shuster et al., 1960; Hardisty et at., 1964; Weatherall and Walker, 1965). While a slight rise of foetal haemoglobin is not uncommon in a variety of leukaemias, very high levels have been noted only in patients with erythroleukaemia (Beaven et al., 1960) and in children with juvenile myeloid leukaemia (Hardisty et al., 1964). The occurrence of associated changes in red cell enzyme levels has not been noted. This report describes the changes in haemoglobin and red cell enzyme patterns over a 12-month period in a child with the clinical features of juvenile myeloid leukaemia and similar studies on 27 children with other types of leukaemia. These studies shed further light on the pathogenesis of juvenile chronic myeloid leukaemia.

Carbonic anhydrase: chemistry, physiology, and inhibition.

Carbonic anhydrase: chemistry, physiology, and inhibition.

BLOOD CARBONIC ANHYDRASE ACTIVITY-A POSSIBLE ROLE IN THE PRODUCTION OF ACID-BASE IMBALANCE IN CHILDREN AND INFANTS.

1. Blood carbonic anhydrase activity was estimated in individuals belonging to four age groups. Our results show that the level of activity in adults is significantly higher than in the newborn. 2. A theory was proposed as to the clinical significance of very low carbonic anhydrase levels in premature babies, the newborn, and very young infants.

Subnormal level of carbonic anhydrase in blood of carcinoma patients?

IT was shown in a recent paper1 that the zinc content of whole blood in cases of very different cancers was subnormal (a mean decrease of about 20 per cent being found). Various metalloproteins are known which contain zinc as an essential part2. It seems wise to devote careful attention to carbonic anhydrase, a substance present in relatively large amounts in red blood corpuscles and described in detail by Keilin and Mann3.

THE RELATIONSHIP BETWEEN CARBONIC ANHYDRASE ACTIVITY AND ZINC CONTENT OF ERYTHROCYTES IN NORMAL, IN ANEMIC AND OTHER PATHOLOGIC CONDITIONS

Abstract A good correlation exists between zinc content and carbonic anhydrase activity of the red blood cells under all conditions studied, including anemia and polycythemia. In almost all patients with anemias other than pernicious anemia, both zinc and carbonic anhydrase levels were lowered in parallel fashion. These changes were proportional to decreases in hematocrit and hemoglobin levels and erythrocyte counts so that both zinc and carbonic anhydrase values per unit of RBC were in the normal range. In a few instances of anemia associated with leukemia and in one of sickle cell anemia, neither zinc content nor carbonic anhydrase activity was decreased in proportion to the anemia; in these cases the zinc and carbonic anhydrase levels per unit of blood were both elevated to the same degree. Patients with pernicious anemia showed no decrease in absolute values for zinc and carbonic anhydrase activity in spite of marked lowering of hematocrit and hemoglobin levels and of erythrocyte count. Accordingly, both zinc concentration and carbonic anhydrase activity per unit of blood were elevated, often to a marked degree. These increases were parallel, varying inversely with the degree of anemia; when they regressed under treatment, both did so at the same rate. There are no methods available for estimating carbonic anhydrase concentration; all methods now in use measure only the activity of the enzyme. It is suggested that zinc concentration could be used as an indicator of carbonic anhydrase content of the red blood cells.