Subcellular distribution of carbonic anhydrase and Na+, K+- and HCO3--ATPases in brains of DBA and C57 mice.
DBA/2J mice are susceptible to audiogenic seizures (ASs) in an age-dependent manner, susceptibility being maximal at 21 days of age and declining thereafter. DBA, as compared with AS-resistant C57BL/6J (C57) mice, had higher carbonic anhydrase (CA) activity in cerebral cortex, brainstem, and cerebellum homogenates at 21 days of age. CA activity was also increased in cytosolic (82%), microsomal (167%), and myelin (68%) subcellular fractions from cerebral cortex, and in cytosolic (51%) and mitochondrial (102%) fractions from brainstem of DBA mice at 21 days of age. In addition, DBA mice had a higher Na+, K+-ATPase activity in myelin from cerebral cortex, and a lower HCO3--ATPase activity in mitochondria from brainstem. The differences in CA activity in the cerebral cortex and in HCO3--ATPase were not present at 110 days of age, when DBA mice are no longer susceptible to ASs. Because CA and HCO3--ATPase are involved in maintaining a proper ionic environment for neuronal function, these data suggest that alterations in activity of these enzymes are related to the age-dependent changes in AS susceptibility in DBA mice.
D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D001639:Bicarbonates / Q000032:analysis; D001923:Brain Chemistry; D002256:Carbonic Anhydrases / Q000032:analysis*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000378:metabolism*; D008811:Mice, Inbred DBA / Q000378:metabolism*; D011188:Potassium / Q000032:analysis; D012964:Sodium / Q000032:analysis
D001639:Bicarbonates; D012964:Sodium; D000251:Adenosine Triphosphatases; D002256:Carbonic Anhydrases; D011188:Potassium