[Evaluation of functional periodicity of the pituitary gland by harmonic analysis.--III Circadian prolactin secretion in subjects with prolactin-secreting adenoma].

: The 24-hour periodicity of PRL secretion in 7 prolactinoma subjects of both sexes has been studied by means of the Fourier's harmonic analysis. In all cases elevated PRL titres have been found, that did not show the physiological changes due to sleep and wake. In most of the cases could not be demonstrated either a significant secretory periodicity or secretory episodes occurred with a frequency higher than in the control groups. Such secretory features may depend on changes in the neoplastic cells' receptors for regulating neurotransmitters.