Increased liver alanine in the tumour-bearing host. Altered levels of some enzymes involved in alanine metabolism
Goodlad, G.A.; Jaffray, E.; Loudon, K.; Clark, C.M.
Biochemistry International 21(2): 279-287
1990
ISSN/ISBN: 0158-5231 PMID: 2403367 Document Number: 352217
A 2-fold increase in hepatic alanine concentration was observed in rats bearing a Walker 256 carcinoma growing sub-cutaneously. Decreases were observed in the activities of both cytosolic and mitochondrial isozyme forms of L-alanine-2-oxoglutarate aminotransferase. Activities of two enzymes involved in a secondary pathway of haem synthesis involving alanine, L-alanine-4,5-dioxovalerate aminotransferase and the NADP-requiring isozyme form of 4-oxo-5-hydroxyvalerate dehydrogenase were also reduced but there was no change in liver porphyrin concentration. L-alanine-glyoxalate aminotransferase activity was unaffected. The results are discussed in relation to the utilisation of alanine as a gluconeogenic substrate in the tumour-bearing host.