[Relationship of the homovanillic acid content in the rat brain after the administration of a neuroleptic and the degree of dopamine receptor sensitivity to an agonist].

In the experiments on male Wistar rats it was established that the intensity of apomorphine stereotypy gradually increased 6--12 hours after a single injection of haloperidol in a dose of 1 mg/kg. 24 hours later the stereotypy was much higher than in the control animals, its intensity being negatively correlated with the homovanillic acid (HVA) concentration in the rat forebrain. It is suggested that HVA concentration reflects the degree of dopamine receptor sensitivity to the agonist.