The stimulation of prolactin secretion by sulpiride in "adolescent gynaecomastia".

In order to evaluate the function of the hypothalamic-pituitary-prolactin axis in "adolescent gynaecomastia" (AG), sulpiride was administered to 7 normal boys and 7 boys with AG. The maximum increase in serum prolactin (PRL) above the mean baseline level (deltamax) was used as index of response. The sulpiride induced a greater PRL release in boys with gynaecomastia than in the controls. Our data indicate that boys with gynaecomastia may have a greater pituitary prolactin pool. The results also illustrate the usefulness of specific neurotrophic agents such as sulpiride as important tools for evaluating the function of the hypothalamic-pituitary-PRL axis.