Visualization of Gene Expression of Short and Long Forms of Prolactin Receptor in Rat Reproductive Tissues

Abstract

Prolactin receptor gene expression was visualized in various tissues by in situ hybridization. Probes specific to the intracellular domains of the short and long form of receptor were prepared. The specificity of these signals was controlled by competition with excess unlabeled homologous probes or heterologous probes; moreover, some tissues, such as penis and vagina, show no expression of either form of receptor mRNA. Macroautoradiogram signals (optical density) were quantified and expressed in arbitrary units. The long form of receptor mRNA was preferentially expressed in testis, epididymis, prostate, seminal vesicle, and mammary gland from lactating animals, whereas the expression of the two forms of mRNA was equivalent in ovary, uterus, and pregnant mammary gland. Signals were also localized at the light microscopic level to individual cells. This approach has permitted the precise localization of prolactin receptor mRNAs in reproductive tissues. Actions of prolactin have not been demonstrated in all tissues expressing receptor transcripts; thus it will be interesting to correlate the expression of long and short forms of receptor with specific functions.

Specificity of the neuroendocrine response to orgasm during sexual arousal in men

“…There is clinical and experimental evidence that the prolactin response to orgasm may not only affect reproductive organs (Outhit et al 1993, Bole-Feysot et al 1998, Goffin et al 1999), but also may play an important role in the control of acute sexual drive after orgasm. This position is supported by a wealth of data from both animal and human studies demonstrating a marked inhibitory effect of hyperprolactinemia on sexual drive, arousal and gonadal function (Doherty et al 1986, Walsh & Pullan 1997, Yazigi et al 1997, Rehmann et al 2000.…”

Detection of In Situ Localization of Long Form Prolactin Receptor Messenger RNA in Lactating Rats by Biotin-Labeled Riboprobe.

“…This is the first report to show the expression of the PRLRL gene in granulosa cells of primary follicles and follicular epithelium of primordial follicles. The failure of previous studies [8,15,16] to localize PRLRL mRNA in the follicular epithelium might be related to the problem of the identification of signals to specify signals in overall tissues due to the background noise of radiolabeled probes. It is not clear whether PRLRL protein is expressed in those cells, since an immunohistochemical study with anti-rabbit mammary gland PRLR antiserum failed to observe signals in those cells [30].…”

“…Identification of the cells expressing the PRLRL gene in target tissues from lactating animals may help identify the physiological role of PRLRL on these tissues in addition to the mammary gland. Recent papers reported the localization of PRLR mRNAs by in situ hybridization with radiolabeled probes with frozen sections [8,[13][14][15][16], but their morphology are not good enough to analyze the expression of specific mRNA sequences at the cell levels. Colorimetric in situ visualization of biotin-labeled nucleic acid in paraffin section by enzyme-labeled streptavidin permits observation of signals in individual cells [17,18].…”

Effects of acute prolactin manipulation on sexual drive and function in males

“…There is clinical and experimental evidence suggesting that the prolactin response to orgasm may not only affect reproductive organs (Outhit et al 1993, Bole-Feysot et al 1998, Goffin et al 1999, but also play a role in the control of acute sexual arousal following orgasm. Supporting this position, chronic elevations of prolactin (hyperprolactinemia), induced by prolactin-secreting tumors or as a side effect of typical neuroleptics, produce pronounced reductions of sexual drive and gonadal functions in animals (Doherty et al 1986) and humans (Yazigi et al 1997, Hummer et al 1999, Knegtering et al 2003.…”