Earlier studies have proved that chronic subcutaneous exposure to the mitochondrial toxin like rotenone has induced features of Parkinson’s disease (PD) in rats. It includes dopaminergic neuron degeneration with decreased tyrosine hydroxylase activity. The aim was to identify the optimum dose of ip rotenone for inducing PD in rat model. The male Wistar rats were injected IP with three doses of rotenone 1, 2 or 3 mg/kg daily for 21 days. The IP administration of 3 mg/kg rotenone produced motor impairment and In addition, it caused a significant decrease in the number of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and dopamine concentration in the striatum. The 1 mg/kg dose did not indicate any damaging effect on body weight after 21 days of daily rotenone IP injections. Moreover, rats in the 3 mg/kg group showed a decreased locomotor activity and shorter latency to fall from a rotarod than control rats. The histopathological and immunohistochemical changes identified in the nigrostriatal neurons, was also evident at this dose.

Parkinsonism, Rotenone, Tyrosine Hydroxylase