Hypotensive action of aggregated IgG in rats. Study of the unresponsiveness to a second dose following restoration of the blood pressure.
Human IgG preparations containing aggregates have been reported to induce hypotension in rats. Animals surviving a hypotensive dose of such a preparation were found unresponsive to a second dose given the next day. Unresponsiveness was induced by an isolated fraction of aggregated IgG, but not by purified monomers. Preparations containing aggregated and monomeric IgG appeared more efficient in inducing unresponsiveness than aggregates alone. The phagocyte function in vivo was assessed in unresponsive animals. No significant difference was found in the carbon clearance and in the human erythrocyte clearance test suggesting that a general impairment of the phagocyte function is not necessary for unresponsiveness. Previous studies indicated the involvement of PAF in hypotension by aggregated IgG. Hypotension was elicited by the injection of PAF in rats made "refractory" to aggregated IgG like in controls.
Jenei
B
B
National Institute of Haematology, Blood Transfusion and Immunology, Budapest, Hungary.
Lázár
G
G
Bartha
K
K
Mihalik
R
R
Medgyesi
G A
GA
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002860:Chromium Radioisotopes; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology*; D016756:Immunoglobulins, Intravenous / Q000494:pharmacology*; D008099:Liver / Q000166:cytology; D010586:Phagocytes / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000166:cytology
D002860:Chromium Radioisotopes; D007074:Immunoglobulin G; D016756:Immunoglobulins, Intravenous