Role of metabotropic glutamate receptors in the mechanisms of experimental parkinsonism development.

We studied the effects of metabotropic glutamate receptor 5 (mGluR5) antagonist 6-methyl-2-(phenylethynyl)-pyridine (MPEP) on the development of catalepsy and NO generation in the striatum of rats under conditions of long-term treatment with low doses of rotenone, a mitochondrial complex I inhibitor. In rats receiving single intraperitoneal injection of rotenone (1.5 mg/kg), NO concentration in the striatum did not differ from that in animals receiving sunflower oil. No signs of catalepsy were observed at these terms in both animal groups. It was demonstrated that long-term rotenone treatment induced catalepsy associated with enhanced NO production in the rat striatum. mGluR5 antagonist MPEP alleviated catalepsy caused by long-term rotenone treatment and prevented rotenone-induced stimulation of NO generation.