Spectrographic Studies of Cancer and Normal Blood Plasma: III. Ultraviolet Absorption Spectra of Fractionated Immune and Normal Rat Blood Plasma

Abstract

In certain experiments on the ultraviolet absorption of normal and cancer rat plasma, fractionated with zinc hydroxide powder, described in a previous paper, 1 it was found that the absorption curves of various samples of normal rat plasma treated with zinc hydroxide were practically identical between wavelengths of 2900 and 3400 A, while those of cancer rat plasma similarly treated deviated from the normal. The deviation was roughly proportional to the size of the tumor growth. It seemed desirable to investigate the plasma of rats which were known to be immune to cancer in order to determine whether a similar difference between normal and immune rats existed. The present study was therefore undertaken, using the same technic, but no significant difference was detected. Procedure The rats used in these experiments were standardized Germantown albino rats, some of which exhibited a natural immunity to cancer. According to the procedure regularly used in this laboratory, implants of a transplantable rat tumor, Walker carcinoma 256, were made into the flanks of the animals. Normally such tumors grow, increasing in size, until the death of the animal. In the case of an immune rat, however, the tumor reaches its maximum growth of about 3 or 4 grams in weight in about two weeks, and then regresses, finally disappearing about ten days thereafter. Subsequent attempts to inoculate these rats with cancer, either sarcoma, Philadelphia No. 1, or with carcinoma, Walker 256, are unsuccessful. In some cases such immunity has been known to last six or seven months. The rats used in these experiments had been originally inoculated six or eight weeks prior to the time of the experiment. In the hope that the immunizing agent might be increased, rat R-11 was injected with a suspension of carcinoma 256, six days before the experiment.