Characterization of myoglobin toxicity in renal cortical slices from Fischer 344 rats

Jennifer L Minigh1, Monica A Valentovic

  • 1Department of Pharmacology, Joan C Edward School of Medicine, Marshall University, 1542 Spring Valley Drive, Huntington, WV 24704-9388, USA.

Toxicology
|April 8, 2003
PubMed

Insights

Myoglobin causes kidney damage through iron-dependent and independent pathways. Glutathione protects kidney cells from myoglobin toxicity, while deferoxamine partially mitigates damage.

Area of Science:

  • Nephrology
  • Toxicology
  • Biochemistry

Background:

  • Rhabdomyolysis, a condition involving muscle breakdown, is a known cause of acute kidney injury.
  • Myoglobin, released during rhabdomyolysis, is implicated in renal damage.
  • Understanding myoglobin's toxic mechanisms is crucial for developing protective strategies.

Purpose of the Study:

  • To characterize the in vitro toxicity of myoglobin on rat renal cortical slices.
  • To investigate the protective effects of deferoxamine (DFX) and glutathione against myoglobin-induced renal cell injury.
  • To elucidate the roles of iron and radicals in myoglobin nephrotoxicity.

Main Methods:

  • Isolated male Fischer 344 rat renal cortical slices were incubated with varying concentrations of myoglobin.
  • Myoglobin was pre-treated with ascorbic acid to ensure a reduced state.
  • Tissues were pre-treated with deferoxamine (iron chelator) or glutathione before myoglobin exposure.

Main Results:

  • Myoglobin exposure led to decreased gluconeogenesis, increased lipid peroxidation, and reduced glutathione levels within 60 minutes.
  • ATP depletion and lactate dehydrogenase (LDH) release occurred after 120 minutes of myoglobin exposure.
  • Deferoxamine reduced LDH release (iron-dependent) but not gluconeogenesis impairment (iron-independent). Glutathione provided complete protection.

Conclusions:

  • Myoglobin induces renal toxicity through both iron-dependent and iron-independent mechanisms.
  • Glutathione effectively protects renal cells from myoglobin toxicity via intracellular pathways.
  • These findings highlight potential therapeutic targets for preventing rhabdomyolysis-induced acute kidney injury.

Related Concept Videos