ABSTRACT
Changes in the total cobalamin content and spectrum of individual forms of these vitamins in blood cells and plasma as well as the activities of enzymatic systems of xenobiotic metabolism in liver microsomes of rats with experimental adjuvant arthritis (AA) have been studied. The total cobalamin content in the blood plasma of rats with AA was increased in comparison with intact animals; however, leucocytes from AA rats were deficient in methylcobalamin (MeCbl). A correlation was found between the ratios of individual cobalamin forms and their total content which was differently expressed in experimental and control animals. The development of AA was associated with marked inhibition of the cytochrome P-450-dependent monooxygenase system of the liver and glutathione transferase. The possibility of correction of these disturbances by MeCbl is discussed.
Subject(s)
Arthritis, Experimental/blood , Microsomes, Liver/enzymology , Mixed Function Oxygenases/metabolism , Vitamin B 12/blood , Xenobiotics/metabolism , Animals , Arthritis, Experimental/enzymology , Glutathione/metabolism , Male , RatsABSTRACT
The influence of cyanocobalamine (CN-B12), cobamide coenzyme (5'-deoxyadenosyl-B12, DBC) and the cytostatic hisphen on the level of cobalamines in the blood serum, liver, kidney, heart and in the tumor of healthy and sarcoma M-1 implanted rats was studied. In the above organs and tissues cobalamines were found to occur in the free and protein-bound state (cobalamine-protein complexes). The complexes were of different stability. The ratio of free to protein-bound cobalamines varied. The content of cobalamine-protein complexes in healthy and tumorous tissues was different. CN-B12, DBC and hisphen influenced specifically the redistribution of cobalamine and protein-bound complexes.
Subject(s)
Cobamides/therapeutic use , Nitrogen Mustard Compounds/therapeutic use , Sarcoma, Experimental/drug therapy , Vitamin B 12/therapeutic use , Animals , Histidine/analogs & derivatives , Histidine/therapeutic use , Kidney/metabolism , Liver/metabolism , Male , Myocardium/metabolism , Neoplasm Transplantation , Rats , Sarcoma, Experimental/metabolism , Vitamin B 12/metabolismABSTRACT
The level of cobalamines in the kidney and liver of healthy rats and rats with implanted Zajdela ascites hepatoma (ZAH) was examined. The results were compared with the data obtained from the rats with sarcoma M-1. It was shown that different tumors had dissimilar effects upon the level of total cobalamines. However, the ratio of free cobalamines to protein-bound cobalamines (cobalamine-protein complexes) varied. The concentration of cobalamine-protein complexes increased in the liver, kidney and in the tumor. The experiments with ZAH demonstrated that ZAH cells contained appreciable amounts of cobalamines, whereas the supernatant contained only a minor quantity of cobalamines. Injections of 5'-deoxyadenosyl-B12 increased the level of cobalamines in ZAH cells and had a low effect on the level of cobalamines in the supernatant.
Subject(s)
Carcinoma, Hepatocellular/metabolism , Cobamides/therapeutic use , Kidney/metabolism , Liver/metabolism , Vitamin B 12/metabolism , Animals , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Liver Neoplasms/metabolism , Male , Neoplasms, Experimental , RatsABSTRACT
The effect of the cobamide coenzyme (5,6-dimethylbenzimidazolyl-Co-5'-deoxyadenozylcobamide, DBC) on the growth of some forms of rat tumours and on the prolongation of survival of rats with implanted Zajdela ascites hepatoma was compared with that of cyanocobalamine (5,6-dimethylbenzimidazolyl-Co-cyanocobamide, CN-B12). The effect of DBC was shown to differ from that of CN-B12. DBC did not stimulate the growth of the investigated forms of tumours and prolonged survival of rats with implanted Zajdela ascites hepatoma. The rats displayed cancer resistance when DBC or CN-B12 were injected before implantation of tumours or Zajdela ascites hepatoma.
