Facilitation of Sexual Receptivity in the Female Rat by a Fragment of the LHRH Decapeptide, Ac-LHRH&lt;sup&gt;5-10&lt;/sup&gt;

Dudley, Carol A.; Vale, Wylie; Rivier, Jean; Moss, Robert L.

doi:10.1159/000123503

Cited by 37 publications

(6 citation statements)

References 8 publications

(12 reference statements)

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“…In this respect, it is of interest that synthetic fragments of LHRH or LHRH analogs have been reported to affect neuronal electric activity [43,44] and to induce mating behavior when microinjected directly into brain structures [6][7][8][9][10][11][12][13] as efficiently as LHRH itself. These effects, in particular induction of mating behavior, appear to depend primarily upon the C-terminal sequence of LHRH; only C-, not Nfragments were found active [14,15], In view of their pro duction in extrahypothalamic structures and of their high er stability towards degradating enzymes, [Hyp9]LHRH derived C-fragments could well represent the endogenous active molecules responsible for those effects. Their ac tion may be mediated by receptors distinct of those of LHRH itself [3][4][5], as suggested by their differential bind ing potency on membrane homogenates prepared from the brain or the pituitary [4], inasmuch as mating behav ior induced by C-fragments of LHRH is not abolished by conventional antagonists of LHRH receptors [17].…”

Section: Physiological Relevance O F C-terminal Derivatives O F Lhrhmentioning

confidence: 99%

“…Specific LHRH receptors are also present in those structures [2][3][4][5] and are probably in volved in the regulation of sex behavior, since intracere bral infusion of the decapeptide or of LHRH analogs is effective in enhancing sexual receptivity and lordosis [6][7][8][9][10][11][12][13]. Interestingly, C-terminal fragments of LHRH were found as effective as LHRH itself on these responses [14][15][16]. These effects could thus be mediated by a distinct subtype of the LHRH receptor recognizing shorter pep tides, inasmuch as behavioral effects of LHRH fragments are not all prevented by LHRH antagonists [17], In a pre vious study, we characterized [hydroxyproline9]LHRFI ([Hyp9]LHRH) [ 18] as an alternate endogenous posttranslational product of the LHRH precursor [ 19].…”

Section: Introductionmentioning

confidence: 99%

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Preferential Distribution of C-Terminal Fragments of [Hydroxyproline<sup>9</sup>]LHRH in the Rat Hippocampus and Olfactory Bulb

Jp¹,

Pattou²,

Leblanc³

et al. 1993

Neuroendocrinology

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Several molecular forms related to the decapeptide LHRH were characterized and quantified in various brain structures of intact and castrated male and female rats. Distinct moieties were separated by high performance liquid chro-matography (HPLC) and radioimmunoassayed against anti-LHRH antibodies of different specificities. The hypothalamus contained the highest concentration of LHRH-like material detected by the antisera. The predominant (89%) molecular form recovered from that structure was LHRH itself; 9% of the material corresponded to [hydroxyproline⁹]LHRH ([Hyp⁹]LHRH), an endogenous posttranslational product of the LHRH precursor, and the residual immunoreactivity was accounted for by C-terminal fragments of both decapeptides, as assessed after labelling HPLC columns with appropriate synthetic or endogenous hypothalamic peptides. The proportions were the same in both sexes and were not affected by castration, in spite of a lesser overall LHRH activity in females and in castrates. LHRH and [Hyp⁹]LHRH were also detected in the olfactory bulb and the hippocampus. In these structures however, most (97%) LHRH-related molecules corresponded to C-fragments derived from [Hyp⁹]LHRH, whereas only very few fragments derived from the nonhydroxylated decapeptide were found. Sex or castration affected neither total nor relative concentrations of LHRH-derived molecules in the olfactory bulb and the hippocampus. Taken altogether, these observations are suggestive of a different LHRH metabolic regulation in neurons projecting to either the median eminence or extrahypothalamic areas. In the latter case, larger amounts of the LHRH precursor appear processed to [Hyp⁹]LHRH. Recovery of relatively high concentrations of [Hyp⁹] LHRH C-fragments in the olfactory bulb and the hippocampus reflects the higher resistance of the Hyp⁹-Gly¹⁰-NH₂ than the Pro⁹-Gly¹⁰-NH₂ peptidic bond to hydrolysis by the postproline cleaving enzyme. In view of reports that intracerebral administration of C-terminal fragments of LHRH are able to trigger sex behavior, our finding that extrahypothalamic structures contain relatively high concentrations of the [Hyp⁹]LHRH-derived, more stable C-fragments suggests that these catabolites may have a role in the regulation of sex behavior.

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Section: Physiological Relevance O F C-terminal Derivatives O F Lhrhmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Preferential Distribution of C-Terminal Fragments of [Hydroxyproline<sup>9</sup>]LHRH in the Rat Hippocampus and Olfactory Bulb

Jp¹,

Pattou²,

Leblanc³

et al. 1993

Neuroendocrinology

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“…Central administration of GnRH (via intraventricular infusion) facilitates lordosis in estrogen-primed rats McCann, 1973, 1975;Pfaff, 1973;Dudley et al, 1983). Further, central infusions of an antibody to GnRH reduce lordosis (Sakuma and Pfaff, 1983).…”

Section: Introductionmentioning

confidence: 99%

Rapid inhibition of female sexual behavior by gonadotropin-inhibitory hormone (GnIH)

Bentley

Jensen

Kaur

et al. 2006

Hormones and Behavior

167

119

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TitleRapid inhibition of female sexual behavior by gonadotropin-inhibitory hormone (GnIH). Abstract Gonadotropin-releasing hormone (GnRH) is largely responsible for the initiation of sexual behaviors; one form of GnRH activates a physiological cascade causing gonadal growth and gonadal steroid feedback to the brain, and another form is thought to act as a neurotransmitter to enhance sexual receptivity. In contrast to GnRH, gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin release. The distribution of GnIH in the avian brain suggests that it has not only hypophysiotropic actions but also unknown behavioral actions. GnIH fibers are present in the median eminence (ME) and are in apparent contact with chicken GnRH (cGnRH)-I and -II neurons and fibers. In birds, cGnRH-I regulates pituitary gonadotropin release, whereas cGnRH-II enhances copulation solicitation in estradiol-primed females exposed to male song. In the present study, we determined the effects of GnIH administered centrally to female white-crowned sparrows. A physiological dose of GnIH reduced circulating LH and inhibited copulation solicitation, without affecting locomotor activity. Using rhodaminated GnIH, putative GnIH binding sites were seen in the ME close to GnRH-I fiber terminals and in the midbrain on or close to GnRH-II neurons. These data demonstrate direct effects of GnIH upon reproductive physiology and behavior, possibly via separate actions on two forms of GnRH.

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“…Central administration of GnRH (via intraventricular infusion) facilitates lordosis in S524 J Ornithol (2007) 148 (Suppl 2):S521-S526 estrogen-primed rats McCann 1973, 1975;Pfaff 1973;Dudley et al 1983). Further, central infusions of an antibody to GnRH reduce lordosis (Sakuma and Pfaff 1983).…”

Section: Sexual Behaviormentioning

confidence: 99%

Gonadotropin-inhibitory hormone in seasonally-breeding songbirds: neuroanatomy and functional biology

et al. 2007

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The discovery of gonadotropin-inhibitory hormone (GnIH) in Japanese Quail Coturnix japonica has given us a new perspective on the neuroendocrine control of reproductive physiology and behavior. Using highly photoperiodic passerine songbirds as our model system, we have been able to investigate GnIH neuroanatomy and functional biology. The distribution of GnIH peptide is similar among the galliform and passerine species studied so far. We have identified GnIH cDNA and localized its transcript in Gambel's White-crowned Sparrow Zonotrichia leucophrys gambelii. There is a high degree of homology between the galliform and passerine GnIH cDNA sequences and peptides. Based on transcript localization, GnIH precursor polypeptide is only produced in the paraventricular nucleus, yet GnIH-immunoreactive fibers project to multiple brain areas, suggesting multiple physiological and behavioral functions. GnIH immunoreactive neurons appear to contact gonadotropin-releasing hormone (GnRH)-I and -II neurons, raising the possibility of direct regulation of GnRH by GnIH. In a photoperiod experiment, GnIH neurons increased in area during the termination of reproduction in Song Sparrows, Melospiza melodia, implying temporal photoperiodic regulation of this neuropeptide. Using peripheral administration of GnIH in vivo, we demonstrated rapid inhibition of LH release in laboratory and field experiments. Furthermore, we sought to determine the effects of central infusions of GnIH. Centrally-administered GnIH rapidly reduced circulating LH and significantly reduced the number of copulation solicitations performed in response to song playback, with no reduction of locomotor activity. Central infusion of rhodaminated GnIH elucidated putative GnIH binding sites in the median eminence close to GnRH-I fiber terminals, and in the midbrain on or close to GnRH-II neurons. These data demonstrate direct effects of GnIH upon reproductive physiology and behavior, possibly at multiple physiological levels and over different time-frames. Thus, the discovery of GnIH has unearthed a complex and interesting system for the regulation of avian reproductive biology.

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Facilitation of Sexual Receptivity in the Female Rat by a Fragment of the LHRH Decapeptide, Ac-LHRH<sup>5-10</sup>

Cited by 37 publications

References 8 publications

Preferential Distribution of C-Terminal Fragments of [Hydroxyproline<sup>9</sup>]LHRH in the Rat Hippocampus and Olfactory Bulb

Preferential Distribution of C-Terminal Fragments of [Hydroxyproline<sup>9</sup>]LHRH in the Rat Hippocampus and Olfactory Bulb

Rapid inhibition of female sexual behavior by gonadotropin-inhibitory hormone (GnIH)

Gonadotropin-inhibitory hormone in seasonally-breeding songbirds: neuroanatomy and functional biology

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