EFFECT OF MERTHIOLATE (LILLY) ON CERTAIN SPECIFIC PRECIPITATION REACTIONS.
Merthiolate (Lilly), a substituted benzoic acid, has been shown to interfere, in concentrations usually used for preservation, with the specific precipitation of antisera against beef serum or sheep serum coupled with diazotized p-aminobenzoic acid, p-arsanilic acid, or p-(p-aminophenylazo) phenylarsonic acid. In some systems increased precipitation was observed, while in others decreased precipitation was observed.
The Serological Properties of Simple Substances. IV. Hapten Inhibition of Precipitation of Antibodies and Polyhaptenic Simple Substances
As part of a series of studies of the antigenantibody reaction by use of polyhaptenic simple substances as antigens,we have made a quantitative investigation of the ability of various substituted phenylarsonic acids to inhibit the precipitation of compounds containing two or more phenylarsonic acid groups with antiserum to sheep serum coupled with diazotized p-arsanilic acid. The investigation included study of the effect of various concentrations of hapten XXIII ([chemical structure]) on the amount of precipitate obtained with antiserum and various concentrations of antigen VI [chemical structure], where R is the p-azophenylarsonic acid group); the effect of changed conditions of precipitation for the same system; the effects of four haptens on the precipitation of each of five antigens and each of two pools of antiserum; and the effects of 24 different haptens on one precipitin reaction. The results are discussed in this paper.
Serological Reactions with Simple Substances Containing Two or More Haptenic Groups.
It has been inferred from inhibition studies that a simple hapten can combine with antibodies homologous to a conjugated protein involving that hapten1 to give soluble compounds. In most cases haptens do not give the precipitin reaiction with antiserum nor produce anaphylactic shock in animals sensitized with corresponding conjugated proteins. It was pointed out recently2 that the framework theory of antibody-antigen precipitates suggests strongly that simple substances containing two or more haptenic groups should, under favorable circumstances, show all of the properties of more complex antigens; the thorough experimental test of this should provide evidence in support of or against the framework theory. Landsteiner and van der Scheer3 observed the occurrence of the precipitin reaction and anaphylaxis with simple substances formed by coupling two anilic acid molecules with resorcinol or tyrosine. On the other hand, Hooker and Boyd4 have reported that they observed no formation of precipitate with several different compounds containing two haptenic groups. In order to obtain further evidence, we have prepared several substances with two or more haptenic groups per molecule and have tested them with suitable serum and with sensitized guinea pigs. We observed precipitate formation with each of the substances, and also observed anaphylaxis and desensitization with one of them, thus verifying the existence of the phenomena reported by Landsteiner and van der Scheer. The serum used in our experiments was obtained from rabbits which had been given a course of six injections (alternately intraperitoneal and intravenous) of azoprotein per week for four weeks, the rabbits being bled nine days after the last injection. The azoprotein used was made by coupling sheep serum protein with diazotized arsanilic acid. Four azoprotein preparations, containing 0.68%, 1.9%, 2.3% and 3.3% arsenic (relative to total protein as determined from Kjeldahl nitrogen), respectively, were used. The titers of the serum of fourteen rabbits given one or another of these preparations were nearly the same, about 0.4 mg. antibody per ml., as found by Kjeldahl nitrogen analysis of the precipitate given with azoproteins made from egg albumin and arsanilic acid. The haptens prepared and tested and the results obtained are shown in table 1.