Effects of long-term aldrin administration on seizure susceptibility of rats.

The effects of long-term administration of sub-convulsive doses of aldrin, an organochlorinated pesticide, on seizure susceptibility of rats were studied. Results show that treatment with the pesticide made the rats more susceptible to sound-induced seizures; an increment in post-seizure depression time after maximal electroshock administration was also observed in aldrin-treated animals. Aldrin administration displaced the control dose-response curves constructed for amphetamine and pentylenetetrazol to the left and right, respectively; no differences were detected between control and aldrin-treated rats for strychnine, picrotoxin or 3-mercaptopropionic acid. The results, discussed in the light of the effects of aldrin on biogenic amines or on the electrophysiology of neurones suggested an involvement of both noradrenergic and alteration excitability of the CNS with the observed increments on seizure susceptibility.