Fatty acid oxidation in lymphocytes from Walker 256 tumor-bearing rats.
The oxidation of fatty acids in lymphocytes from the mesenteric lymph nodes of Walker 256 carcinosarcoma-bearing rats (TB) was studied, as well as the activity of the mitochondrial long-chain fatty acid transport system. Two-month old Wistar rats were subcutaneously implanted with 10(7) cells and after 2 weeks the tumor mass was 15-20% of the carcass weight. The activity of carnitine palmitoyltransferase (CPT) II was demonstrable in the lymphocytes of the TB group (8.2 +/- 5.6 nmol/min per mg mitochondria protein for 15 rats) and was not detected in the control, while that of CPT I was only slightly increased in the former. Similar rates of [1-14C]-palmitate decarboxylation were found for TB and control rat lymphocytes. However, when the rate of decarboxylation of [1-14C]-palmitate present in the intracellular pool of lipids was investigated in cultured lymphocytes, the cells of TB rats exhibited rates 17-fold higher than those of control animals in the presence of fetal calf serum (FCS). Decarboxylation in the presence of TB rat serum was 178-fold higher than obtained with normal rat serum, and 1.4-fold compared to FCS. These results suggest that, during cachexia, lymphocytes preferably oxidize intracellular lipids, and that this capacity is greatly enhanced by factors circulating in the serum of tumor-bearing rats.
Seelaender
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MC
Departamento de Histologia e Embriologia, Universidade de São Paulo, Brasil.
Costa-Rosa
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LF
Curi
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D000818:Animals; D002279:Carcinoma 256, Walker / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar
D005227:Fatty Acids