Toxicity of a Serotonin-Derived Neuromelanin

Document Type

Article

Publication Title

Biochemical and Biophysical Research Communications

Abstract

Postoperative Cognitive Dysfunction (POCD) is associated with increased mortality in the elderly and may occur from lipid peroxidation in aging. We previously showed that sevoflurane sequesters acrolein, which promotes the formation of a novel species of a putative neuromelanin. The current study examined the properties of this serotonin-derived melanoid (SDM). The interaction of SDM with unilamellar vesicles (ULVs) was examined using lipid membrane probes. Vesicle disruption was investigated by leakage of dye from calcein-loaded ULVs. We observed that SDM decreased diphenyl-hexatriene fluorescence anisotropy and increased the temperature-dependent change in anisotropy. SDM changed the absorbance of merocyanin-bound ULVs. SDM increased detergent-mediated calcein leakage. SDM structure was dramatically altered upon interaction with ULVs. We also observed that SDM enhanced detergent-mediated leakage of loaded ULVs, suggesting that SDM may be neurotoxic. We propose that inhalational agents, which sequester acrolein, may promote the production of certain species of neuromelanin that depletes local serotonin and enhances neuronal vulnerability.

DOI

10.1016/j.bbrc.2009.12.085

Publication Date

1-8-2010

Keywords

Acrolein, Inhaled anesthetics, Neuromelanin, Neurotoxicity, Postoperative Cognitive Dysfunction, Serotonin, Unilamellar vesicles

ISSN

1090-2104

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