“…This idea is supported by the findings that (i) PRLR expression was located in pituitary lactotrophs (e.g., rat, Morel et al, 1994), and (ii) PRL treatment could suppress PRL secretion in pituitary cells (e.g., rat, Bentley and Wallis, 1987) and lactotroph cell lines (e.g., GH3 cells, Melmed et al, 1980). Unlike the inhibitory effect on PRL release, no consensus has been reached for the autocrine actions of PRL on PRL synthesis, as no effect (Melmed et al, 1980) and inhibition on PRL production/gene expression (Devost and Boutin, 1999) have been reported. To date, the local actions of other pituitary hormones, e.g., GH and luteinizing hormone (LH), on PRL secretion/gene expression are still unclear.…”