Effect of Ca2+ and Mg2+ on the Mn-superoxide dismutase from rat liver and heart mitochondria

V. Pérez-Vázquez, J. Ramírez, L. Aguilera-Aguirre, J. C. González-Hernández, M. Clemente-Guerrero, S. Manzo-Ávalos, S. Uribe, A. Saavedra-Molina

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


The manganese superoxide dismutase (Mn-SOD) converts super-oxide anions to hydrogen peroxide plus oxygen, providing the first line of defense against oxidative stress in mitochondria. Heart mitochondria exhibited higher Mn-SOD activity than liver mitochondria. In mitochondria from both tissues Mn-SOD activity decreased after incubation at low oxygen concentration (hypoxic mitochondria). The effects of free Ca2+ ([Ca2+]f) and free Mg2+ ([Mg2+]f) on normoxic and hypoxic mitochondria from either organ were tested. In normoxic mitochondria from either tissue, both [Ca2+]f and [Mg2+]f activated the enzyme, although [Mg2+]f was less efficient as an activator and the effect was lower in heart than in liver mitochondria. When added simultaneously, high [Ca2+]f and [Mg2+]f exhibited additive effects which were more pronounced in heart mitochondria and were observed regardless of whether mitochondria had been incubated under normal or low oxygen. The data suggest that [Ca2+]f plays a role in regulating Mn-SOD in concert with the activation of aerobic metabolism.

Original languageEnglish (US)
Pages (from-to)405-416
Number of pages12
JournalAmino Acids
Issue number4
StatePublished - 2002
Externally publishedYes


  • Amino acids
  • Calcium
  • Heart mitochondria
  • Liver mitochondria
  • Magnesium
  • Mn-SOD
  • Superoxide anion

ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Organic Chemistry


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