Chronic progesterone treatment of male rats with unilateral 6-hydroxydopamine lesion of the dorsal striatum exasperates parkinsonian symptoms

▶Progesterone was daily applied over 13 days starting 1 day after unilateral injection of 6-OHDA into the dorsal striatum of male rats. ▶Chronic progesterone administration increased the DOPAC/DA ratio in the lesioned striatum, increased 6-OHDA-lesion-induced motor impairments. ▶Our results raise the question of possible negative interactions between progesterone and parkinsonian symptoms in males.