title: Ca(2+)-dependent nonspecific permeability of the inner membrane of liver mitochondria in the guinea fowl (Numida meleagris).
abstract: This comparative study presents the results of the induction of Ca(2+)-dependent nonspecific permeability of the inner membrane (pore opening) of rat and guinea fowl liver mitochondria by mechanisms that are both sensitive and insensitive to cyclosporin A (CsA). It was established that energized rat and guinea fowl liver mitochondria incubated with 1 mM of inorganic phosphate (Pi) are capable of swelling upon addition of at least 125 and 875 nmol of CaCl2 per 1 mg protein, respectively. Under these conditions, the Ca(2+) release from the mitochondria of these animals and a drop in Δψ are observed. All of these processes are inhibited by 1 μM of CsA. FCCP, causing organelle de-energization, induces pore opening in rat and guinea fowl liver mitochondria upon addition of 45 и 625 nmol of CaCl2 per 1 mg protein, respectively. These results suggest the existence of a CsA-sensitive mechanism for the induction of Ca(2+)-dependent pores in guinea fowl liver mitochondria, which has been reported in rat liver mitochondria. However, guinea fowl liver mitochondria have a significantly greater resistance to Ca(2+) as a pore inducer compared to rat liver mitochondria. It was found that the addition of α,ω-hexadecanedioic acid (HDA) to rat and guinea fowl liver mitochondria incubated with CsA and loaded with Ca(2+) causes organelle swelling and Ca(2+) release from the matrix. It is assumed that in contrast to the CsA-sensitive pore, the CsA-insensitive pore induced by HDA in the inner membrane of guinea fowl liver mitochondria, as well as in rat liver mitochondria, is lipid in nature.
authors.affiliation: Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El, 424001, Russia.
authors.forename: Aleksander A
authors.initials: AA
authors.lastname: Vedernikov
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Dubinin
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Zabiakin
authors.forename: Victor N
authors.initials: VN
authors.lastname: Samartsev
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002122:Calcium Chloride / Q000378:metabolism; D019069:Cell Respiration / Q000502:physiology*; D016572:Cyclosporine / Q000494:pharmacology*; D046094:Galliformes / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051336:Mitochondrial Membranes / Q000378:metabolism*; D008933:Mitochondrial Swelling / Q000187:drug effects; D010101:Oxygen Consumption / Q000502:physiology; D010169:Palmitic Acids / Q000494:pharmacology; D010539:Permeability / Q000187:drug effects; D010710:Phosphates / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D013045:Species Specificity
chemical_list: D010169:Palmitic Acids; D010710:Phosphates; C012346:hexadecanedioic acid; D016572:Cyclosporine; D002122:Calcium Chloride; D002118:Calcium