Immunodetection of rat Walker 256 tumour mitochondrial carnitine palmitoyltransferase I and II: evidence for the control of CPT II expression by insulin.
The purpose of the study was to separate the mitochondrial proteins of rat Walker 256 tumour tissue and perform immunodetection studies to identify the carnitine palmitoyltransferase I (CPT I) and CPT II proteins previously reported to be present in this tumour. CPT I protein was undetectable using antibody raised against rat liver CPT I and was therefore considered to be immunologically different from that found in normal rat tissues such as heart, liver and skeletal muscle. In contrast, CPT II protein was readily detected in Walker 256 tumour and had an apparent Mr of approximately 70,000, as was found for rat liver. The in vivo treatment of tumour-bearing rats with insulin caused an increase in the expression of CPT II protein in the tumour tissue. The data confirm that CPT II can be regulated by insulin and also demonstrate that tumour CPT I may be a different isoform from that present in rat liver.
Colquhoun
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Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Brasil.
Curi
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R
D000818:Animals; D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western; D002279:Carcinoma 256, Walker / Q000201:enzymology*; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007328:Insulin / Q000494:pharmacology*; D007527:Isoenzymes / Q000276:immunology / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008297:Male; D008928:Mitochondria / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar
D000906:Antibodies; D007328:Insulin; D007527:Isoenzymes; D002334:Carnitine O-Palmitoyltransferase