RESUMO
The effect of heparin on isolated rabbit heart mitochondria was studied in usual clinical (0.25 u/ml) and higher doses. Hepain concentration 0.25 u/ml stimulated respiration in the state 4, decreased ADP/O ratio and phosphorylation rate and did not affect mitochondria ultrastructure. Higher concentration caused two-phase changes in respiration-short-time stimulation with the following inhibition, oxidative phosphorylation (respiratory control, ADP/O, phosphorylation rate) was progressively depressed and decoupled. The mitochondria ultrastructure is changed under the influence of 1.25 u/ml and of higher doses; the external membrane lost its two-layer character, the crista were converted into a small granular mass. Concentration of 1.25 u/ml transformed many mitochondria into empty vesicles.
