Involvement of Prolactin-Releasing Peptide in the Preovulatory Luteinizing Hormone and Prolactin Surges in the Rat

Hizume, Takatoshi; Watanobe, Hajime; Yoneda, Masashi; Suda, Toshio; Schiöth, Helgi B.

doi:10.1006/bbrc.2000.3895

Cited by 28 publications

(19 citation statements)

References 25 publications

(30 reference statements)

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“…Of interest in this regard, Seal et al (2000) have reported a significant stimulatory effect of PrRP on plasma LH and follicle-stimulating hormone in male rats following intracerebroventricular injection. Further, in female rats treated with oestrogen, central injection of anti-PrRP serum suppresses the LH and prolactin surges (Hizume et al 2000). Clearly, further studies of both rats and sheep are required to determine whether there are major species differences in the roles of PrRP that can account for these different responses.…”

Section: Discussionmentioning

confidence: 99%

Prolactin-releasing peptide in the ewe: cDNA cloning, mRNA distribution and effects on prolactin secretion in vitro and in vivo

Curlewis

Kusters²,

Barclay³

et al. 2002

Journal of Endocrinology

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RT-PCR followed by 5 -and 3 -rapid amplification of cDNA ends was used to clone and sequence ovine prolactin-releasing peptide (PrRP). The cDNA was characterised by short 5 -and 3 -untranslated regions and a GC-rich (71%) coding region. The nucleotide and deduced amino acid sequences for the coding region showed 95·6 and 94·9% identity with bovine PrRP but the amino acid sequence of PrRP31 was conserved between these species. Northern blot analysis and RT-PCR showed that, as in the rat, the peptide was more abundantly expressed in the brainstem than the hypothalamus. However, in the ovine hypothalamus, PrRP mRNA expression was more widespread than in the rat, with expression detected in both rostral and caudal parts of the mediobasal hypothalamus. The effects of synthetic ovine PrRP on prolactin secretion both in vitro and in vivo were also examined. In primary cultures of sheep pituitary cells, PrRP significantly (P<0·01) increased prolactin concentrations in the culture medium but the response was not observed in every experiment and was only seen when pituitary glands were dispersed with collagenase rather than trypsin. PrRP was much less potent than TRH which caused a significant (P<0·01) two-to threefold increase in prolactin concentrations in every experiment. Intravenous (10 and 50 nmol) or intracerebroventricular (10 and 50 nmol) injection of PrRP had no significant effect on either plasma prolactin concentration or pulsatile LH secretion whereas intravenous injection of TRH (10 nmol) produced a highly significant (P<0·01) and more than sevenfold stimulation of plasma prolactin concentrations. In conclusion, these results suggest that PrRP is unlikely to be an important prolactin-releasing factor in this species.

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Section: Discussionmentioning

confidence: 99%

Prolactin-releasing peptide in the ewe: cDNA cloning, mRNA distribution and effects on prolactin secretion in vitro and in vivo

Curlewis

Kusters²,

Barclay³

et al. 2002

Journal of Endocrinology

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“…Although these biochemical characteristics of PrRP may support the concept that the neuropeptide is a reasonable candidate for a physiological PRL-releasing factor, a number of in vivo [5, 6, 7, 8]and in vitro [9]studies conducted to date have argued against this possibility. However, this author and coworkers recently reported that PrRP may play a significant role in mediating the steroid induced PRL surge in the rat [10]. This was probably the first finding that indicates a significant involvement of PrRP in a specific physiological event which is normally associated with a profuse release of PRL from the pituitary.…”

Section: Introductionmentioning

confidence: 90%

In vivo Release of Prolactin-Releasing Peptide in Rat Hypothalamus in Association with Luteinizing Hormone and Prolactin Surges

Watanobe

2001

Neuroendocrinology

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Prolactin (PRL)-releasing peptide (PrRP) is a novel hypothalamic peptide reported to be a potent and specific stimulator of PRL secretion. This author recently reported that PrRP might play a significant role in mediating the steroid-induced PRL surge in the rat. In order to examine the secretory profile of PrRP in the rat hypothalamus before and during the luteinizing hormone (LH) and PRL surges, this study employed the push-pull perfusion technique and determined the in vivo release of PrRP and also of gonadotropin-releasing hormone (GnRH) in ovariectomized rats primed with estradiol and progesterone. In the medial preoptic area (MPOA) where the GnRH neuronal perikarya exist, GnRH release was increased prior to the initiation of the LH surge, and PrRP also started rising even earlier than GnRH. In the median eminence-arcuate nucleus complex (ME-ARC), where GnRH neuronal fibers terminate, GnRH secretion started increasing before the commencement of the LH surge, but the release of PrRP did not change significantly. These results suggest that PrRP may play a role in mediating the steroid-induced LH surge by activating GnRH neurons in the MPOA. A possible involvement of PrRP in the PRL surge was not suggested from the present data. The lack of a significant alteration in PrRP release in the ME-ARC may argue against a direct hypophysiotropic action of the peptide.

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“…It now appears unlikely that PrRP stimulates prolactin release in vivo (Taylor & Samson 2001), despite there being evidence that PrRP is involved in regulating the secretion of other hypothalamopituitary factors, including corticotrophin-releasing hormone, follicle-stimulating hormone (FSH) and luteinising hormone (LH), and oxytocin (Maruyama et al 1999b, Hizume et al 2000, Samson et al 2003.…”

Section: Prrp Familymentioning

confidence: 99%

The role of RFamide peptides in feeding

Bechtold

Luckman

2007

Journal of Endocrinology

116

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In the three decades since FMRFamide was isolated from the clam Macrocallista nimbosa, the list of RFamide peptides has been steadily growing. These peptides occur widely across the animal kingdom, including five groups of RFamide peptides identified in mammals. Although there is tremendous diversity in structure and biological activity in the RFamides, the involvement of these peptides in the regulation of energy balance and feeding behaviour appears consistently through evolution. Even so, questions remain as to whether feedingrelated actions represent a primary function of the RFamides, especially within mammals. However, as we will discuss here, the study of RFamide function is rapidly expanding and with it so is our understanding of how these peptides can influence food intake directly as well as related aspects of feeding behaviour and energy expenditure.

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Involvement of Prolactin-Releasing Peptide in the Preovulatory Luteinizing Hormone and Prolactin Surges in the Rat

Cited by 28 publications

References 25 publications

Prolactin-releasing peptide in the ewe: cDNA cloning, mRNA distribution and effects on prolactin secretion in vitro and in vivo

Prolactin-releasing peptide in the ewe: cDNA cloning, mRNA distribution and effects on prolactin secretion in vitro and in vivo

In vivo Release of Prolactin-Releasing Peptide in Rat Hypothalamus in Association with Luteinizing Hormone and Prolactin Surges

The role of RFamide peptides in feeding

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