In the course of examining the etiology of the Lucké renal adenocarcinoma of the frog, Rana pipiens, it was found that organs of the normal adult contain bacteriolytic enzymes. These enzymes all satisfied the six criteria for the identification of lysozymes and at least eight forms were separable by polyacrylamide gel electrophoresis. Their qualitative and quantitative distribution was organ-specific. All eight isozymes were found in normal kidney, while liver and spleen contained seven forms; skin, six; ovarian egg, five; and serum, two. In quantitative assays using a radial diffusion test, spleen had the greatest lysozyme concentration, followed in descending order by kidney, liver, skin, and ovary. Serum contained very low amounts. In terms of enzyme activity per animal, ovary was the highest ranking organ. As such a large number of lysozyme isozymes has not been reported in any other organism, their origins and functions are considered in the context of their presence in an ectotherm.
The occurrence of macromolecular change accompanying differentiation in embryonic or neoplastic development is well recognized, even if poorly understood.'+ In the course of immunochemical studies on macromolecular changes related to differentiation in the amphibian,".' we have had occasion to examine the antigenic composition of the frog kidney and of the frog renal adenocarcinoma, which is believed to be of viral origin.", I" The following is a report of observations on antigenic differences between the normal and tumor kidney of the frog, on the possible identity of one of these antigens, and on some differences between tumor-susceptible and resistant f rogs.1'-*3 Materials and M e t hodsAntigens. R a n a pipiens obtained from Alberg, Vt., were used as the source of embryos, normal organs, and tumors, from which "supernatant" fractions were prepared".I5 at 0 to 4" C. by homogenization from the frozen state i n two volumes of phosphate buffered saline, pH 7.4, and centrifugation at 12,000 g for 20 minutes. These supernatants were used as injection or test antigens after adding merthiolate. Although all the renal adenocarcinomas were palpable, they were not of uniform histological character and i t was impossible to be assured of complete separation of tumor from "normal" tissues.The bacteriolytic enzyme described below was prepared from ovaries or larvae (Shumway Stages 19-23) because of the limited supply of normal kidneys. A bentonite adsorption procedure modified from the method for chicken egg white lysozyme was used."' Ovaries from two to three frogs were ground in 80 ml. of 0.85 per cent NaCI, adjusted to pH 4 to 4.5 with acetic acid and rehomogenized, frozen and thawed three times, and centrifuged at 10,000 g. The precipitate was reprocessed in 40 ml. of 0.85 per cent NaCI. The supernatants were pooled, filtered, adjusted to pH 6.8
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.