ABSTRACT
L-canavanine, an analogue of L-arginine, is known to have a toxic effect on pathogens. In experiments performed on a specialised epithelial-like cell system which is conditionally transformable, L-canavanine appeared to exhibit (1) a reversible 'static' effect on exponentially growing cells at optimal concentration, and (2) a selectively toxic effect on proliferating cells. The capacity to recognise 'tumour cells' in a heterogeneous population of cells is of potential interest in cancer chemotherapy.
Subject(s)
Antineoplastic Agents , Canavanine/pharmacology , Animals , Cell Division/drug effects , Cell Line , DNA Replication/drug effects , Drug Evaluation, Preclinical/methods , Haplorhini , Membrane Fluidity/drug effects , Models, Biological , Mutation , Neoplasms, Experimental/pathology , TemperatureABSTRACT
The blood, spleen and liver of RFM/Un mice were examined by means of electron spin resonance (ESR) throughout the course of myeloid leukaemia induced by i.v. injection of leukaemic spleen cells. Marked changes in the concentration of iron transferrin and caeruloplasmin were observed in the blood 1 day after injection. As the disease progressed, changes occurred in the concentrations of the ascorbyl radical and of paramagnetic metal complexes in both spleen and liver. These changes are compared with those induced in RF/J mice injected with normal and leukaemic spleen cells from RFM/Un mice.
Subject(s)
Leukemia, Myeloid/metabolism , Animals , Ascorbic Acid/metabolism , Ceruloplasmin/metabolism , Electron Spin Resonance Spectroscopy , Female , Leukemia, Experimental/metabolism , Liver/metabolism , Male , Mice , Mice, Inbred Strains , Organ Size , Spleen/metabolism , Time Factors , Transferrin/metabolismABSTRACT
The ascorbyl radical concentration has been observed, by means of electron spin resonance spectroscopy, in the blood and spleen of female Wistar rats carrying a Yoshida tumour. The ascorbyl radical concentration of the tumour tissue itself was studied as the tumour was developing, and as it was regressing after treatment with methylene dimethane sulphonate. Changes in the concentration of this radical may be related to host tumour reactions.
Subject(s)
Ascorbic Acid/analysis , Electron Spin Resonance Spectroscopy , Sarcoma, Yoshida/analysis , Animals , Female , Mesylates/pharmacology , Muscles/analysis , Neoplasm Transplantation , Rats , Spleen/analysis , Transplantation, HomologousABSTRACT
Electron spin resonance (ESR) spectroscopy was used to examine changes in the concentration of paramagnetic metal ions in Yoshida tumours carried by female Wistar rats. Blood, spleen and lymph nodes from these animals were also examined by ESR. A decrease in the concentration of a paramagnetic species associated with mitochondrial activity, and marked increases in those thought to be associated with inflammatory or immune reactions and cell lysis, were observed in the tumours within one day of implantation. During development of the tumour, and during its regression after treatment with methylene dimethane sulphonate (MDMS), further changes were observed in the concentration of the species. These were dependent on the region of the tumour examined. In blood, development of the tumour produced an increase in ceruloplasmin and a decrease in iron-transferrin. An increase in spleen weight, as the tumour developed, was accompanied by a small decrease in the concentration of species with g-values of 6-0 and 4-3, which was reversed on regression of the treated tumour. The presence of metastases in the regional lymph nodes produced distinguishable changes in the ESR spectra.
