Regional glycine receptor binding in the p,p'-DDT myoclonic rat model.

Abnormal glycinergic neurotransmission has been implicated in the pathophysiology of DDT-induced myoclonus. To examine the role of glycine receptors in the DDT model, was measured [3H]strychnine receptor binding in brainstem and spinal cord in the rat after acute administration of DDT. The highest dose of DDT tested significantly increased both Bmax (20%) and Kd (57%) of glycine sites in spinal cord but not brainstem compared to vehicle-treated controls at 4 h. Lower DDT doses, which also induced myoclonus, had no significant effects on [3H]strychnine specific binding. In vitro, 10(-7) DDT did not displace [3H]strychnine binding in naive rat spinal cord, but higher doses could not be studied due to poor solubility of DDT under the assay conditions. These data suggest that only a maximal dose of DDT has significant though mixed effects on parameters of [3H]strychnine binding in spinal cord which are not correlated with the onset of myoclonus.