| Autor: |
Zavodnik IB; Department of Biochemistry, Yanka Kupala State University of Grodno, Grodno, Belarus., Kovalenia TA; Department of Biochemistry, Yanka Kupala State University of Grodno, Grodno, Belarus., Veiko AG; Department of Biochemistry, Yanka Kupala State University of Grodno, Grodno, Belarus., Lapshina EA; Department of Biochemistry, Yanka Kupala State University of Grodno, Grodno, Belarus., Ilyich TV; Department of Biochemistry, Yanka Kupala State University of Grodno, Grodno, Belarus., Kravchuk RI; Grodno State Medical University, Grodno, Belarus., Zavodnik LB; Department of Biochemistry, Yanka Kupala State University of Grodno, Grodno, Belarus., Klimovich II; Grodno State Medical University, Grodno, Belarus. |
| Abstrakt: |
The aim of the present work was to elucidate the mechanisms of calcium ion-induced impairments of the ultrastructure and functional activity of isolated rat liver mitochondria in the absence and presence of a number of flavonoids in vitro. In the presence of exogenous Ca²⁺ (20-60 μM), mitochondrial heterogeneity in size and electron density markedly increased: most organelles demonstrated a swollen electron-light matrix, bigger size, elongated cristae and a reduced their number, a damaged native structure of the inner membrane up to its detachment, and some mitochondria showed a more electron-dense matrix (condensed mitochondria). The calcium-induced opening of the mitochondrial permeability transition pores (MPTP) resulted in the ultrastructural disturbances and in the effective inhibition of the respiratory activity of rat liver mitochondria. The flavonoids (10-25 μM) naringenin and catechin, dose-dependently inhibited the respiratory activity of mitochondria and stimulated the MPTP opening in the presence of Ca²⁺ ions. Since Ruthenium red, an inhibitor of the mitochondrial Ca²⁺ uniporter, effectively prevented Ca²⁺-induced MPTP opening both in the absence and presence of flavonoids, we hypothesized that the effect of flavonoids on the MPTP opening could be mediated by stimulation of the Ca²⁺ uniporter. |
