Perturbation of liver microsomal calcium homeostasis by ochratoxin A.
Biochem Pharmacol
; 38(1): 67-72, 1989 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-2910308
ABSTRACT
The effect of ochratoxin A on hepatic microsomal calcium sequestration was studied both in vivo and in vitro. The rate of ATP-dependent calcium uptake was inhibited by 42-45% in ochratoxin A intoxicated rats as compared to controls. In the presence of NADPH, addition of ochratoxin A (2.5 to 100 microM) caused a concentration-dependent inhibition of calcium uptake (28-94%) by untreated rat liver microsomes. The rate of NADPH-dependent lipid peroxidation, measured as malondialdehyde formed, was also greatly enhanced by ochratoxin A. Various agents that inhibited ochratoxin A enhanced lipid peroxidation were also able to block the destruction of calcium uptake activity. Lipid peroxidation enhanced by ochratoxin A was also accompanied by leakage of calcium from calcium-loaded microsomes. These results suggest that ochratoxin A disrupts microsomal calcium homeostasis by an impairment of the endoplasmic reticulum membrane probably via enhanced lipid peroxidation.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microssomos Hepáticos
/
Cálcio
/
Homeostase
/
Ocratoxinas
Limite:
Animals
Idioma:
En
Revista:
Biochem Pharmacol
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
Canadá