title: Guinea pig macroalbumin. A major inhibitor of activated Hageman factor in plasma with an alpha 2-macroglobulin-like nature.
abstract: A major inhibitor of the beta form of activated Hageman factor (beta-HFa) with an apparent molecular weight of 28,000, which was reported as a strong permeability factor (Yamamoto and Cochrane, Am J Pathol 1981, 105: 164-175), was purified from guinea pig plasma. When it was depleted in vitro, the plasma lost 71% of the total inhibitory activity toward beta-HFa. The inhibitor, termed "macroalbumin," with an apparent molecular weight of 720,000 and an apparent pI of 4.6, seemed to be an inhibitor similar to alpha 1- or alpha 2-macroglobulin of man and other mammalian species in physicochemical characteristics and in enzymologic properties. Though the inhibitory activity to beta-HFa was negligible in normal skin extract, a significant inhibitory activity appeared in extracts of permeability-enhanced skin sites which were induced by intradermal beta-HFa injection. The inhibitory activity that appeared was macroalbumin-dependent, with more than a 10-fold increase in the concentration. These results indicate the roles of macroalbumin as a negative feedback regulator in situ to the Hageman-factor-dependent pathway in a permeability enhancement system.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D002199:Capillary Permeability; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005174:Factor XII / Q000037:antagonists & inhibitors*; D005260:Female; D006168:Guinea Pigs; D007122:Immunoelectrophoresis; D007525:Isoelectric Focusing; D007700:Kinetics; D008297:Male; D008744:Methylamines / Q000494:pharmacology; D012867:Skin / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism*
chemical_list: D000906:Antibodies; D008744:Methylamines; D014361:Trypsin Inhibitors; D000511:alpha-Macroglobulins; D005174:Factor XII; C027451:methylamine