[Study of the turnover or the release of brain dopamine in rats after administration of N-linoleyl dopamine]. / Etude de la vitesse de renouvellement ou de libération de la dopamine cérébrale chez le rat après administration de N-linoléyl dopamine.

ABSTRACT

Wistar male rats received N-linoleyl dopamine (L-DA) at doses of 10, 50 or 100 mg/kg (i.p.). 2 h after these injections they were decapitated and dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), as well as the ratio DOPAC/DA, which could represent the DA turnover, were determined in the striatum, the frontal cortex or the hypothalamus, while homovanillic acid (HVA) as well as the ratio HVA/DA, which could represent the DA release, were determined in the striatum by high performance liquid chromatography (HPLC). Except a small rise of DA and DOPAC in the hypothalamus, at high L-DA doses, no significant modifications in DA, DOPAC, DOPAC/DA, HVA or HVA/DA were observed in the other brain areas studied. These results, in good agreement with the recent data obtained with other dopaminergic agonists, could show the absence of correlation between the hypomotility, on the one hand and the decreasing of the turnover or the release of the brain DA, on the other hand. Together with the data obtained recently by scandinavian and italian authors, they could raise questions about the position and the role of dopaminergic autoreceptors.