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Abnormal dopamine sensitivity in some human prolactinomas.

I Pellegrini·R Costa·F Grisoli·P Jaquet
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Abstract

In most of human prolactin (PRL)-secreting adenomas, dopamine and dopamine agonists normally suppress the excessive PRL secretion. Nevertheless, a subpopulation of such patients presents a relative insensitivity to the ergot derivative bromocriptine. Six patients with a macroadenoma (n = 5) or microadenoma (n = 1) were considered resistant to bromocriptine which, at a daily dose of 15-60 mg, did not normalize high plasma PRL levels. Culture studies of these adenoma cells showed that: (1) 10(-8) M bromocriptine produced a 32 +/- 16% inhibition of PRL release versus 65 +/- 12% obtained in the same conditions with normal human pituitary cells; (2) sulpiride (10(-6) M) reversed the inhibitory effects of bromocriptine, and (3) the bacterial endotoxins, cholera toxin (10(-11) M) and pertussis toxin (250 ng/ml), respectively, produced a 45-500% increase and a total abolition of bromocriptine-induced PRL inhibition. These observations and recent data of the literature allow to discuss the possibility of receptor or postreceptor defects in such tumors.

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BromocriptineCells, CulturedDopamineFemaleHumansPituitary NeoplasmsProlactinomaReceptors, DopamineJournal Article

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BibTeXRIS

I Pellegrini, R Costa, F Grisoli, P Jaquet. 1989. Abnormal dopamine sensitivity in some human prolactinomas.. https://doi.org/10.1159/000181081

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