Pharmacologic investigation in mice of the effects of narcotic antagonists on dopamine agonist reversal of oxotremorine or reserpine

In the present study, two different drugs were used to induce a Parkinson-like condition. The first drug was the centrally acting cholinergic agonist oxotremorine (OXTM) which readily induces tremor and rigidity in mice (54). This tremor has been reported to be antagonized by dopamine agonists such as L-dopa and apomorphine (50,54,55) as well as by anticholinergic drugs such as scopolamine (46) . The other drug used was reserpine which interferes with the neuronal storage of dopamine and results in its depletion in the brain (56). Reserpine induces tremor, rigidity, blepharoptosis (a drooping of the eyelids), and catalepsy (48,57-59). The catalepsy is readily reversed by the administration of L—dopa (48,60-62). Using these two models of Parkinson\u27s disease, selected narcotic antagonists have been tested to determine if they could potentiate dopaminergic influences and restore the normal balances of acetylcholine and dopamine in the corpus striatum