Adrenocortical changes and uptake of 4-14C-corticosterone in rats intoxicated with fenitrothion

A significant increase in plasma corticosterone levels and depletion of ascorbic acid content in adrenal glands occurred in rats between 1 and 5 h after a single dose (50% LD₅₀) of fenitrothion, returning to normal levels within 12 h; brain AChE activity decreased to about 59–43% and significant inhibition of the enzyme was observed for up to 24 h after intoxication. Repeated dosing with fenitrothion (2.5% LD₅₀) for 14 days caused insignificant elevation of plasma corticosterone levels, while brain AChE activity was inhibited to about 19% of control values and uptake of 4-¹⁴C-corticosterone in tissues was significantly diminished.