Tl^sup +^ induces both cationic and transition pore permeability in the inner membrane of rat heart mitochondria

• Published in: Journal of bioenergetics and biomembranes 2013-12, Vol.45 (6), p.531
• Main Authors: Korotkov, Sergey M, Nesterov, Vladimir P, Brailovskaya, Irina V, Furaev, Viktor V, Novozhilov, Artemy V
• Format: Article
• Language: English
• Subjects: Adenosine diphosphate; ATP; Heart; Membranes; Mitochondria; Muscles; Permeability; Rodents; Thallium
• ISSN: 0145-479X; 1573-6881
• DOI: 10.1007/s10863-013-9526-8

Effects of Tl^sup +^ were studied in experiments with isolated rat heart mitochondria (RHM) injected into 400 mOsm medium containing TlNO3 and a nitrate salt (KNO3 or NH^sub 4^NO3) or TlNO3 and sucrose. Tl^sup +^ increased permeability of the inner membrane of the RHM to K^sup +^ and H^sup +^. This manifested as an increase of the non-energized RHM swelling, in the order of sucrose < K^sup +^ < NH^sub 4^ ^sup +^, respectively. After succinate administration, the swollen RHM contracted. The Tl^sup +^-induced opening of the mitochondrial permeability pore (MPTP) in Ca^sup 2+^-loaded rat heart mitochondria increased both the swelling and the inner membrane potential dissipation, as well as decreased basal state and 2,4-dinitrophenol-stimulated respiration. These effects of Tl^sup +^ were suppressed by the MPTP inhibitors (cyclosporine A, ADP, bongkrekic acid, and n-ethylmaleimide), activated in the presence of the MPTP inducer (carboxyatractyloside) or mitoK^sub ATP^ inhibitor (5-hydroxydecanoate), but were not altered in the presence of mitoK^sub ATP^ agonists (diazoxide or pinacidil). We suggest that the greater sensitivity of heart and striated muscles, versus liver, to thallium salts in vivo can result in more vigorous Tl^sup +^ effects on muscle cell mitochondria.[PUBLICATION ABSTRACT]