[Increased expression of voltage-dependent anion channel and adenine nucleotide translocase and the sensitivity of calcium-induced mitochondrial permeability transition opening pore in the old rat heart].

We investigated mRNA and protein expression of voltage-dependent anion channel (VDAC), mRNA adenine nucleotide translocase (ANT) as well as the sensitivity of the mitochondrial permeability transition pore opening (MPTP) to Ca2+ in the adult and old rat heart. It was shown that in the old rats hearts VDAC mRNA expression increased by 1.7 (p < 0.05) times and mRNA ANT expression increased by 1.8 (p < 0.05) times in comparison with adult animals. The Western Blot analysis showed that the level of VDAC protein expression in the old rat hearts also significantly increased compared with adult animals. In the hearts of old rats, the sensitivity of MPTP opening to calcium (10(-7)-10(-4) mol/l) determined by mitochondria swelling, increased two-fold (p < 0.05). Therefore, an increased VDAC and ANT expression, as the main structural functional components of the MPTP, and an increased sensitivity of MPTP opening to Ca2+ caused an increase in the permeability of mitochondrial membranes in aging. Each of these factors may contribute to alterations in mitochondrial barrier properties and lead to mitochondrial dysfunction.