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In vivo effect of toxaphene on calcium pump activity in rat brain P2 fraction was studied. Male Sprague-Dawley rats (200-250 g) were dosed with toxaphene at 0, 25, 50, and 100 mg/kg X d for 3 d and sacrificed 24 h after last dose. Ca2+-ATPase activity and 45Ca2+ uptake were determined in brain P2 fraction. Toxaphene decreased both Ca2+-ATPase activity and 45Ca2+ uptake, and the reduction was dose-dependent. Both substrate and Ca2+ activation kinetics of Ca2+-ATPase indicated noncompetitive type of inhibition, as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The decreased Ca2+-ATPase activity and 45Ca2+ uptake were restored to normal level by exogenously added calmodulin, which increased both velocity and affinity. The inhibition of Ca2+-ATPase activity and 45Ca2+ uptake and restoration by calmodulin suggests that toxaphene may impair active calcium transport mechanisms by decreasing levels of calmodulin.
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
March 2009,
Cell biochemistry and function,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
May 1986,
Fundamental and applied toxicology : official journal of the Society of Toxicology,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
March 1991,
Biochemistry international,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
January 1988,
Journal of toxicology and environmental health,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
October 1991,
Journal of toxicology and environmental health,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
January 1989,
Toxicology,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
February 1981,
Biochemical pharmacology,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
June 1997,
Biochimica et biophysica acta,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
February 1985,
Life sciences,
K S Moorthy, and
C H Trottman, and
C H Spann, and
D Desaiah
June 1989,
Research communications in chemical pathology and pharmacology,
