Quantitative correlation of dopamine-dependent adenylate cyclase with responses to levodopa in various mice.

Abstract

Mice (12 groups) with widely different neurological responses to L-dopa were obtained by selecting them from different strains and some were submitted to pretreatments. The symptoms evoked were scored by a standardized dose of L-dopa in 1 subgroup from each group. Another subgroup was tested for activation of an adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] by a standardized dose of dopamine added to homogenates of the caudate nuclei of the brains of these mice. Both sets of tests were performed randomly. When the accruing 2 sets of data were plotted against each other there emerged a straight line which fitted the data with a coefficient of correlation of 0.97 (P < 0.0001). The dopamine-dependent activity of the adenylate cyclase of the brain was shown to be a determinant of the neurological responses of intact animals to a dopaminergic drug.