[Prolactin secreting cell lines: a tool for the study of the mechanism of action of hypophysiotropic neuropeptides. A review (author's transl)].

This review summarizes the characteristics and advantages of cultures of clonal cell lines for studying the mechanism of action of hypothalamic hypophysiotropic factors. Results concerning the interaction of Thyroliberin (TRH) and Vasoactive Intestinal Peptide (VIP) with prolactin-secreting rat pituitary clonal cell lines are summarized here as an illustration. The TRH-prolactin cell interaction appears to be very complicated. The characteristics of 3H-TRH binding sites as well as those of the induced biological effect (PRL stimulation) appears relatively well established. In contrast, the primary event triggered by TRH, as well as the sequence of the intracellular mechanisms of the binding-secretion coupling remain to be established. VIP is shown to be another direct and potent PRL stimulating hypothalamic peptide in PRL producing cell lines. Its stimulating effect is additive to that of TRH and seems to involve a cAMP dependent process.