Lipogenesis from pyruvate

Figure 2.4. The provision of acetyl-CoA and NADPH for lipogenesis. PPP, pentose phosphate pathway T, tricarboxylate transporter K, a-ketoglutarate transporter. In ruminants, pyruvate dehydrogenase, ATP-citrate lyase and malic enzyme activities are low and perhaps non-functional. (From Murray et al., 1988. Harper s Biochemistry, 21st edn, p. 207, Appleton and Lange, Norwalk, CT reproduced with permission of The McGraw-Hill Companies).

Moreover, the relative sensitivity of the tissues was in the same order as the relative sensitivity of the three species to the hypoglycemic action of the biguanides. In another investigation, a number of the effects of phenformin on metabolism in rat adipose tissue,— Inhibition of glucose oxidation and lipogenesis, both basal and insulin stimulated— were traced to an inhibition of pyruvate oxidation, presumably resulting from interference with electron transport. 

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