| 1. |
- Paola Carlini, Valeria, et al.
(författare)
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Acute ghrelin administration reverses depressive-like behavior induced by bilateral olfactory bulbectomy in mice
- 2012
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Ingår i: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 35:2, s. 160-165
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Tidskriftsartikel (refereegranskat)abstract
- This study aims to examine the antidepressant-like action of Ghrelin (Ghr), a hormone synthesized predominantly by gastrointestinal endocrine cells and released during periods of negative energy balance, in two behavioral models: tail suspension test (TST), a predictive model of antidepressant activity, and the olfactory bulbectomy (OB), an established animal model of depression. The reduction in the immobility time in the TST was the parameter used to assess antidepressant-like effect of Ghr. The depressive-like behavior in olfactory bulbectomized mice was inferred through the increase in the immobility time in the TST and the hyperlocomotor activity in the open-field test. Ghr produced antidepressant-like effect in TST (0.3 nmol/mu l, i.c.v.), and reversed OB-induced depressive-like behavior. In conclusion, these results provide clear evidence that an acute administration of ghrelin produce antidepressant-like effect in the TST and OB.
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| 2. |
- Belen Poretti, Maria, et al.
(författare)
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Reproductive performance of male mice after hypothalamic ghrelin administration
- 2018
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Ingår i: Reproduction. - : BIOSCIENTIFICA LTD. - 1470-1626 .- 1476-3990. ; 156:2, s. 121-132
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Tidskriftsartikel (refereegranskat)abstract
- It has been demonstrated that food intake and reproductive physiology are both simultaneously modulated to optimize reproductive success under fluctuating metabolic conditions. Ghrelin (GHRL) is an orexigenic peptide identified as the endogenous ligand of the growth hormone secretagogue receptor that is being investigated for its potential role on reproduction. Considering that data available so far are still limited and characterization of GHRL action mechanism on the reproductive system has not been fully elucidated, we studied the participation of hypothalamus in GHRL effects on sperm functional activity, plasma levels of gonadotropins and histological morphology in mice testes after hypothalamic infusion of 0.3 or 3.0 nmol/day GHRL or artificial cerebrospinal fluid (ACSF) at different treatment periods. We found that GHRL 3.0 nmol/day administration for 42 days significantly reduced sperm concentration (GHRL 3.0 nmol/day =14.05 +/- 2.44 x 10(6)/mL vs ACSF =20.33 +/- 1.35 x10(6)/mL, P< 0.05) and motility (GHRL 3.0 nmol/day =59.40 +/- 4.20% vs ACSF =75.80 +/- 1.40%, P< 0.05). In addition, histological studies showed a significant decrease percentage of spermatogonia (GHRL 3.0 nmol/day =6.76 +/- 0.68% vs ACSF =9.56 +/- 0.41%, P< 0.05) and sperm (GHRL 3.0 nmol/day =24.24 +/- 1.92% vs ACSF =31.20 +/- 3.06%, P< 0.05). These results were associated with a significant reduction in luteinizing hormone and testosterone plasma levels (P < 0.05). As GHRL is an orexigenic peptide, body weight and food intake were measured. Results showed that GHRL increases both parameters; however, the effect did not last beyond the first week of treatment. Results presented in this work confirm that central GHRL administration impairs spermatogenesis and suggest that this effect is mediated by inhibition of hypothalamic-pituitary-gonadal axis.
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| 3. |
- Poretti, María Belén, et al.
(författare)
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Role of the hypothalamus in ghrelin effects on reproduction : sperm function and sexual behavior in male mice
- 2023
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Ingår i: Reproduction. - : Bioscientifica. - 1470-1626 .- 1476-3990. ; 165:1, s. 123-134
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Tidskriftsartikel (refereegranskat)abstract
- Ghrelin (GHRL) is an orexigenic peptide that has been investigated as one of the signals responsible for the reproductive performance of mammals under fluctuating metabolic conditions. Central GHRL administration impairs spermatogenesis in mice by regulating the hypothalamic-pituitary-gonadal axis function. In the present study, the hypothalamus role as a mediator of GHRL effects on sperm fertilizing capacity and male sexual behavior was evaluated. After 42 days of hypothalamic GHRL infusion or artificial cerebrospinal fluid, in vitro and in vivo sperm fertilizing capacity, testicular alpha-tubulin, speriolin gene expression and spermatic alpha-tubulin protein were evaluated. Hypothalamic expression of genes Kiss1, Gpr54 and Gnrh was also studied. The second group of animals was infused with one time only GHRL or artificial cerebrospinal fluid into the hypothalamus to evaluate the effects on sexual behavior. Results demonstrated that chronic GHRL administration to male mice significantly increased the percentages of pre-implantation embryo loss and the number of post-implantation embryo loss. In relation to the gene expression, our results show a relative decrease of Kiss1, Gpr54 and Spatc1. Although no significant differences were observed in the quantitative expression of alpha-tubulin protein, qualitative changes in its expression pattern were observed. In addition, a dual effect on sexual behavior was observed: 40% of the treated animals showed a significant reduction in the number of mounts and intromissions, while a 60% showed a significant decrease in ejaculation latency vs control animals. In conclusion, our results provide evidence that central GHRL administration possibly induces failure in embryo development and/or implantation in the females mated with treated males, possibly because of a negative effect in the alpha-tubulin pattern.
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