A comparison of two catalase preparations used to examine vascular permeability.

Beef liver catalase has been used as a tracer in cytochemical studies of vascular permeability. The use of Sigma catalase C-40 and C-100 preparations in capillary permeability studies of the ileojejunum and choriocapillaris was examined. Catalase C-40 is restricted by the fenestrated capillaries of the ileojejunum in contrast to their permeability to C-100. The choriocapillaris restricts both catalase preparations. Sephadex G-200 chromatography of plasma samples incubated with catalase C-40, or from C-40-injected animals, demonstrated an increase in the molecular weight of the tracer. No increase in molecular weight was evident for catalase C-100. The isoelectric point of both preparations was 5.4-5.7. These findings indicate that Sigma catalase C-100 is the preferred preparation for use in vascular permeability studies.