Differential sensitivities to the lethal, but not the neurotoxic, effects of p-chloroamphetamine in inbred rat strains.
The Lewis, Fischer 344, Brown Norway, Spontaneously Hypertensive, and Wistar-Kyoto inbred rat strains were, respectively, compared for the lethal and neurotoxic effects of acute p-chloroamphetamine (PCA, 2.5-10 mg/kg i.p.). The lethal properties of the amphetamine were recorded within 24 h after its administration whereas neurotoxicity (as assessed by frontocortical 5-hydroxytryptamine (5-HT) reuptake and 5-HT transporter binding assays) was analyzed 1 week after PCA administration. Preliminary experiments indicated that neither the rapid hyperlocomotor and/or the hypoexploratory effect of PCA nor the in vitro potency of PCA to inhibit frontocortical [(3)H]5-HT reuptake varied between strains. On the other hand, strain differences were observed with respect to the rapid fatal effects of the 5 and 10 mg/kg doses of PCA administration. Lastly, frontocortical [(3)H]5-HT reuptake and [(3)H]citalopram binding at 5-HT transporters diminished in a dose-dependent, but strain-independent, manner 1 week after the acute injection of PCA. This study reveals an independency between the mechanisms underlying the fatal effects of PCA on the one hand, and the long-term damaging effects of PCA on serotonergic neurons on the other hand.