Uptake of [3H]dopamine into dopaminergic and noradrenergic neurones of the isolated neurointermediate lobe of the rat hypophysis. Effects of desipramine and nomifensine.
The isolated neurointermediate lobe (NIL) of the rat hypophysis accumulates [3H]dopamine from the incubation medium. Column chromatographic analysis showed that 92% of the tissue radioactivity was contained in the catecholamine fraction. [3H]Dopamine represented 70% and [3H]noradrenaline 30% of the [3H]catecholamines. Desipramine (1 microM) prevented the formation of [3H]noradrenaline without affecting the storage of [3H]dopamine. Nomifensine (10 microM) blocked the storage of [3H]dopamine and [3H]noradrenaline. Thus, in the NIL, [3H]dopamine is taken up into dopaminergic and noradrenergic neurones. In the latter, [3H]dopamine is converted to [3H]noradrenaline, indicating a significant dopamine beta-hydroxylase activity in the NIL tissue. A selective labeling of the dopamine stores with [3H]dopamine can be achieved in the presence of desipramine.
D000818:Animals; D003891:Desipramine / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009627:Nomifensine / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism; D010904:Pituitary Gland, Posterior / Q000166:cytology* / Q000187:drug effects; D051381:Rats
D007546:Isoquinolines; D009627:Nomifensine; D003891:Desipramine; D004298:Dopamine; D009638:Norepinephrine