Carbonic anhydrase isozymes of osteoclasts and erythrocytes of osteopetrotic microphthalmic mice.
The content of carbonic anhydrase isozymes I (CA I) and II (CA II) in red blood cells and bone of osteopetrotic microphthalmic (mi/mi) mice was analyzed. Monospecific rabbit polyclonal antibodies against purified rat carbonic anhydrase I or II detected both isozymes in hemolysates of both normal and mi/mi mice. Total carbonic anhydrase activity measurements of hemolysates from normal or mi/mi mice were identical. A procedure based on bromopyruvate inactivation was devised to measure the relative contributions of CA I and II isozymes to the carbon dioxide hydration activity of hemolyzates. CA II dominates the observed activity of hemolysates of normal and mi/mi mice. Immunohistochemical studies showed that CA II was present in osteoclasts of tibial and calvarial bones of both normal and mi/mi mice. Thus, in contrast to the several cases of inherited osteopetrosis in humans, there is no lack of active CA II in erythrocytes of mi/mi mice. The absence of CA II, therefore, does not appear to play a role in the etiology of osteopetrosis in the mi/mi mouse.
D000818:Animals; D002256:Carbonic Anhydrases / Q000032:analysis*; D004794:Enzyme Repression; D004912:Erythrocytes / Q000201:enzymology*; D007527:Isoenzymes / Q000032:analysis*; D051379:Mice; D010010:Osteoclasts / Q000201:enzymology*; D010022:Osteopetrosis / Q000201:enzymology*; D013977:Tibia / Q000201:enzymology
D007527:Isoenzymes; D002256:Carbonic Anhydrases