Effects of carbocromene on performance and oxidation of FFA and glucose in isolated atria

Abstract

¹⁴C-FFA and ¹⁴C-carbohydrate are oxidized by isolated atria with increasing concentrations according to an apparent Michaelis Menten kinetics. K_m-values and V_max of the substrates are different, which can be explained by variations of diffusion through the cell membrane, the mitochondrial membrane, and variations of the enzyme activities in the different pathways to the Krebs-cycle. In experiments with combined substrates the mutual competition and the participation of substrates in biological oxidation depends on the K_m- and V_max-values as well as the concentrations of the substrates (5, 4). Drugs can interfere here by activation or inhibition of key enzymes in the different pathways to the biological oxidation or by interaction in the penetration of substrates through the membranes.