Genetic control of quantitative variation in carbonic anhydrase isozymes of mammals. I. The concentration within single erythrocytes of the mouse

Proteomic analysis of simulated occupational jet fuel exposure in the lung

We analyzed protein expression in the cytosolic fraction prepared from whole lung tissue in male Swiss-Webster mice exposed 1 h/day for seven days to aerosolized JP-8 jet fuel at concentrations of 1000 and 2500 mg/m3, simulating military occupational exposure. Lung cytosol samples were solubilized and separated via large scale, high resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant quantitative and qualitative changes in tissue cytosol proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass fingerprinting, confirmed by sequence tag analysis, and related to impaired protein synthetic machinery, toxic/metabolic stress and detoxification systems, ultrastructural damage, and functional responses to CO2 handling, acid-base homeostasis and fluid secretion. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression and corroborate previous morphological and biochemical evidence. Further molecular marker development and mechanistic inferences from these observations await proteomic analysis of whole tissue homogenates and other cell compartment, i.e., mitochondria, microsomes, and nuclei of lung and other targets.

Carbonic anhydrase: an ultrastructural study in rat cerebellum

The cellular and intracellular distribution of carbonic anhydrase isozyme II in rat cerebellum has been investigated with the electron microscope by the indirect antibody immunohistochemical technique. Unequivocal evidence is presented supporting the view that this enzyme is exclusively localized in oligodendrocytes. Myelin does not appear to contain detectable amounts of carbonic anhydrase though it is present in oligodendrocyte processes and in the layer of oligodendrocyte cytoplasm frequently seen to coat the external surface of myelinated fibres. The immune precipitate is found to be confined to the cytosol and the cytosolic surfaces of intracellular membranes. The data are discussed in relation to the possible function of the enzyme and the role of oligodendrocytes in the central nervous system.