PubMed |
(0) (0 Votes)
|
Views: (1093) Date: (20-01-09) Pages: () |
Abstract: NADH-dependent respiration in osmotically inactive swollen mitochondria: does transport replace phosphorylation in mediating respiratory control in swollen mitochondria? Sitar amam V, Sambasivarao D. Department of Zoology, University of Poona, Pune. Rotenone-sens itive, uncoupler-insensitiv e, NADH-dependent respiration was demonstrated in osmotically inactive fragments of the mitochondrial inner-membrane obtained following high amplitude (spontaneous) swelling. This NADH-dependent respiration as well as mitochondrial ATPase activity was stimulated by ligands which are known to be transported by specific transporters/mechani sms. The ligands capable of this anomalous respiratory control included several intermediates of the citric acid cycle, besides non-metabolizable ligands including lactate, cations such as K+ and Ca2+. The interaction between NADH-dependent respiration and these ligands, as manifested by stimulation of respiration, was strongly ionic strength-dependent. The thermodynamic relationship between respiratory control and stimulation of transport ATPase by the relevant transportable ligands could also be demonstrated in the conventional (rat liver) microsomes. These experimental results offer a novel experimental base for search into an intra-membranous mechanism of energy transduction. PMID: 1752631 [PubMed - indexed for MEDLINE]