Abstract
Resistance to heat and acidity of the antibody to arsenious acid was investigated by Y. Yamasaki (2) . Serum of the guinea pigs actively sensitized by intracutaneous injections of arsenious acid was heated or acidified, and a definite amount of the treated serum was intravenously injected into normal guinea pigs, whose hypersensitivity was determined by skin reaction to arsenious acid in the manner already mentioned (1) . The serum was heated in the water-bath for 30 minutes at various degrees ; and it was acidified with weak acetic acid solution, changes of pH being measured by the colorimetric method, and neutralized with dilute sodium hydroxide solution before use. It was found that sensitizing ability of the serum was impaired very slightly at pH 5.6 and to a noticeable degree at pH 5.1, and almost completely lost at pH 4.6-4.1. As for the effect of heating it was disclosed that allergizing function was practically unaffected at 56°C, slightly impaired at 60°-65°C, markedly hindered at 70°C and almost completely lost at 75°C. Subsequently, H. Harada (3) has made like experiments in search of effects of heating and acidity upon antibodies to iodine, potassium bichromate and formaldehyde, pursuing the methods of previous workers (4, 5, 6) in sensitization and in tests of reactions. He determined hypersensitivity to iodine by the intestinal reaction and to the other substances by skin reactions, and obtained results similar to those of Y. Yamasaki.
A more extensive study was done by M. Hara (7) . Not only serum but also its globulin fraction of guinea pigs sensitized with egg albumin, picric acid or iodine (iodine-glycerine) were used in his experiments, and effects on their sensitizing abilities of heating, acidity, alkalinity, adsorption and formaldehyde were examined. Active sensitization and provocation of reactions with picric acid and iodine were accomplished by the methods used by previous authors (4, 8) . To sensitize with egg albumin, 2 doses of 0.3 cc of 5% albumin solution per 100 g of body weight were injected with the interval of one day. Globulin solution was prepared as stated by Swineford (9) . After special treatments, sera and globulin solutions were injected in the following amounts per 100 g of body weight ; 1.5 cc of anti-albumin serum, 2.0 cc of anti-picric acid serum, 2.0 cc of anti-iodine serum, 2.0 cc of anti-albumin globulin, 2.5 cc of anti-picric acid globulin, and 2.5 cc of anti-iodine globulin. And 24 hours later anaphylactic reactions were detected by the skin test for picric acid and by Dale tests for egg albumin and iodine, 1.0 cc of 0.05% solution being used in case of egg albumin. Heating and acidification were carried out as described above. For alkalification, dilute sodium hydroxide solution was added, pH was measured, and one hour later the serum or globulin solution was neutralized with acetic acid. To test the effect of formaldehyde, formalin was added to make up 0.25%, 0.5% or 1.0%, and then the serum or globulin solution was dialysed with collodion sac to remove free formaldehyde. In the treatment of adsorption, animal charcoal powder (Merck) was added to 5% or 10%, and the mixture was shaken for 20 minutes, left in the ice box for 24 hours, centrifuged, and the supernatant fluid was used.
Antibodies to three different substances did not show any difinite difference in resistance; sera and globlin solutions resisted to those treatments without noticeable difference. Experiments opt the effect of heating indicated that sensitizing function was impaired slightly by heating at 60°C for 30 minutes, moderately at 60°C for one hour, and destroyed almost completely at 60°C for 2 hours. It was affected slightly by acidity at pH 6.0, noticeably at pH 5.5-5.0 and destroyed at pH 4.0. Alkalinity impaired it slightly at pH 8.5, markedly at pH 9.0-9.5 and to a greater extent at pH 10.0.
