ANTIGENIC PROPERTIES OF PURIFIED FRACTIONS FROM ASCARIS LUMBRICOIDES VAR. SUUM ON NATURALLY SENSITIZED GUINEA‐PIG

Abstract

Purified extract of Ascaris injected intravenously into guinea‐pigs produced a reaction very similar to the anaphylactic reaction. As shown by the ratio of deaths to survivals the toxic fraction contained in Ascaris extract was purified 3 to 4 times. After intravenous injection animals presented both anaphylaxis‐like shock and mast cell damage similar to that observed in anaphylaxis. Perfusion of the lungs with Ascaris fractions released histamine. Isolated guinea‐pig ileum when in contact with Ascaris fractions showed a response followed by desensitization. Heating the ileum to 45° C or previous desensitization to anaphylatoxin excluded the participation of the latter in this contraction. In vitro, sensitization from one guinea‐pig could be transferred to another, using spleen extract or a 50% ammonium sulphate precipitate obtained from the spleen extract. On the basis of these results it is concluded that guinea‐pigs are naturally sensitized to antigen or antigens present in Ascaris lumbricoides. 1961 British Pharmacological Society