title: Endogenous protective mechanisms in remodeling of rat heart mitochondrial membranes in the acute phase of streptozotocin-induced diabetes.
abstract: The aim of present study was to investigate functional and physical alterations in membranes of heart mitochondria that are associated with remodeling of these organelles in acute phase of streptozotocin-induced diabetes and to elucidate the role of these changes in adaptation of the heart to acute streptozotocin-induced diabetes (evaluated 8 days after single dose streptozotocin application to male Wistar rats). Action of free radicals on the respiratory chain of diabetic-heart mitochondria was manifested by 17 % increase (p<0.05) in oxidized form of the coenzyme Q(10) and resulted in a decrease of states S3 and S4 respiration, the respiratory control index, rate of phosphorylation (all p<0.01) and the mitochondrial transmembrane potential (p<0.05), but the ADP/O ratio decreased only moderately (p>0.05). On the contrary, membrane fluidity and the total mitochondrial Mg2+-ATPase activity increased (both p<0.05). In diabetic heart mitochondria, linear regression analysis revealed a reciprocal relationship between the increase in membrane fluidity and decrease in trans-membrane potential (p<0.05, r = 0.67). Changes in membrane fluidity, transmembrane potential, Mg2+-ATPase activity and the almost preserved ADP/O ratio appear as the manifestation of endogenous protective mechanisms participating in the functional remodeling of mitochondria which contributes to adaptation of the heart to diabetes.
authors: Institute for Heart Research, Centre of Excellence in Cardiovascular Sciences, Slovak Academy of Sciences, Bratislava, Slovakia. usrdmife@savba.sk
authors: M
authors: M
authors: Ferko
authors: D
authors: D
authors: Habodászová
authors: I
authors: I
authors: Waczulíková
authors: J
authors: J
authors: Mujkošová
authors: J
authors: J
authors: Kucharská
authors: L
authors: L
authors: Šikurová
authors: B
authors: B
authors: Ziegelhoffer
authors: J
authors: J
authors: Styk
authors: A
authors: A
authors: Ziegelhoffer
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000503:physiopathology; D004579:Electron Transport; D005609:Free Radicals / Q000378:metabolism; D008297:Male; D008560:Membrane Fluidity; D053078:Membrane Potential, Mitochondrial; D008929:Mitochondria, Heart / Q000201:enzymology / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D005609:Free Radicals; D014451:Ubiquinone; D017301:Ca(2+) Mg(2+)-ATPase; C024989:coenzyme Q10