title: Measurement by ELISA of complement factor 4 (C4) in the rat brain: necessity for removal of cerebrovascular proteins.
abstract: Assessment of complement 4 (C4) levels in experimental animals is used as a marker for activation of the classical complement pathway. The objective of this study was to develop a method for measuring C4 concentrations in the rat brain. An ELISA (sensitivity = 0.5 ng C4/ml) was used to measure C4 in regional brain homogenates from Fischer rats cardiac-perfused with phosphate buffered saline to remove cerebrovascular contents, and from sham-perfused rats. Ventral midbrain C4 levels were increased (p < 0.001) versus frontal cortex and striatum in sham-perfused rats, whereas after perfusion there were no differences between brain regions. Removal of cerebrovascular contents decreased C4 by 43% in striatum, 52% in frontal cortex, and 69% in ventral midbrain (all p < 0.01 versus sham-perfused means). These results indicate that C4 in the rat brain can be measured quantitatively by ELISA provided that cerebrovascular proteins are removed by perfusion.
authors.affiliation: Division of Neurology, William Beaumont Hospital Research Institute, 3811 West Thirteen Mile Rd., Royal Oak, MI 48073, USA. DLoeffler@beaumont.edu
authors.forename: David A
authors.initials: DA
authors.lastname: Loeffler
authors.forename: Dianne M
authors.initials: DM
authors.lastname: Camp
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D003181:Complement C4 / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D008297:Male; D009419:Nerve Tissue Proteins / Q000302:isolation & purification*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D003181:Complement C4; D009419:Nerve Tissue Proteins