Prostaglandin inhibition of amphetamine-induced circling in mice.

The effect of prostaglandins (PG) on amphetamine(AMPH)-induced circling was examined in mice unilaterally lesioned with 6-hydroxy-dopamine. At doses of 0.03-1.0 nmol/g, intraventricularly injected PGD2, PGE2, and PGF2 alpha all inhibited AMP-induced circling, while thromboxane-B2 (TxB2) was inactive at 1.0 nmol/g. The inhibition of circling was not due to alterations in body temperature as measured by rectal temperature changes. When injected intrastriatally, the same major PG inhibited AMP-induced circling at the lower doses of 0.01-0.1 nmol/g, while the PGE2 metabolite 13, 14-dihydro-15-keto-PGE2 was inactive at 0.1 nmol/g. PG administered alone did not procude circling. For both routes of administration, the order of potency was PGE2 greater than PGD2 greater than PGF2 alpha. These results suggest that PG can alter motor function governed by central dopaminergic pathways.