title: On the properties of calcium-induced permeability transition in neonatal heart mitochondria.
abstract: Permeability transition was examined in heart mitochondria isolated from neonate rats. We found that these mitochondria were more susceptible to Ca(2+)-induced membrane leakiness than mitochondria from adult rats. In K(+) containing medium, at 25 °C, mitochondria were unable to accumulate Ca(2+). Conversely, in Na(+) containing medium, mitochondria accumulated effectively Ca(2+). At 15 °C mitochondria accumulated Ca(2+) regardless of the presence of K(+). Kinetics of Ca(2+) accumulation showed a similar Vmax as that of adult mitochondria. Lipid milieu of inner membrane contained more unsaturated fatty acids than adult mitochondria. Aconitase inhibition and high thiobarbituric acid-reactive substances (TBARS) indicate that oxidative stress caused mitochondrial damage. In addition, proteomics analysis showed that there is a considerable diminution of succinate dehydrogenase C and subunit 4 of cytochrome oxidase in neonate mitochondria. Our proposal is that dysfunction of the respiratory chain makes neonate mitochondria more susceptible to damage by oxidative stress.
authors: Departamento de Bioquímica, Instituto Nacional de Cardiología, Ignacio Chávez, Juan Badiano # 1, Tlalpam, Mexico, DF, 014080, Mexico.
authors: Natalia
authors: N
authors: Pavón
authors: Juan Carlos
authors: JC
authors: Gallardo
authors: Luz María
authors: LM
authors: Hernández-Esquivel
authors: Mohammed
authors: M
authors: El-Hafidi
authors: Mabel
authors: M
authors: Buelna-Chontal
authors: Cecilia
authors: C
authors: Zazueta
authors: Sara
authors: S
authors: Rodríguez-Enríquez
authors: Edmundo
authors: E
authors: Chávez
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004579:Electron Transport / Q000187:drug effects; D008929:Mitochondria, Heart / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D010539:Permeability / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D051381:Rats
chemical_list: D011188:Potassium; D002118:Calcium