| 1. |
- 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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| 2. |
- Bianconi, Santiago, et al.
(författare)
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Effects of dietary omega-3 PUFAs on growth and development : Somatic, neurobiological and reproductive functions in a murine model.
- 2018
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Ingår i: Journal of Nutritional Biochemistry. - : Elsevier BV. - 0955-2863 .- 1873-4847. ; 61, s. 82-90
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Tidskriftsartikel (refereegranskat)abstract
- Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are relevant to fetal and infant growth and development. Objective: to assess whether long-term exposure to dietary ω-3 PUFA imbalance alters pre- and/or postnatal pups' development and reproductive function later in life. Mice dams were fed with ω-3 PUFA Control (soybean oil, 7%), Deficient (sunflower oil, 7%) or Excess (blend oil; 4.2% cod-liver+2.8% soybean) diet before conception and throughout gestation-lactation and later on, their pups received the same diet from weaning to adulthood. Offspring somatic, neurobiological and reproductive parameters were evaluated. Excess pups were lighter during the preweaning period and shorter in length from postnatal day (PND) 7 to 49, compared to Control pups (P<.05). On PND14, the percentage of pups with eye opening in Excess group was lower than those from Control and Deficient groups (P<.05). In Excess female offspring, puberty onset (vaginal opening and first estrus) occurred significantly later and the percentage of parthenogenetic oocytes on PND63 was higher than Control and Deficient ones (P<.05). Deficient pups were shorter in length (males: on PND14, 21, 35 and 49; females: on PND14, 21 and 42) compared with Control pups (P<.05). Deficient offspring exhibited higher percentage of bending spermatozoa compared to Control and Excess offspring (P<.05). These results show that either an excessively high or insufficient ω-3 PUFA consumption prior to conception until adulthood seems inadvisable because of the potential risks of short-term adverse effects on growth and development of the progeny or long-lasting effects on their reproductive maturation and function.
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| 3. |
- Bianconi, Santiago, et al.
(författare)
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Ghrelin restores memory impairment following olfactory bulbectomy in mice by activating hippocampal NMDA1 and MAPK1 gene expression
- 2021
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Ingår i: Behavioural Brain Research. - : Springer Nature. - 0166-4328 .- 1872-7549. ; 410
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Tidskriftsartikel (refereegranskat)abstract
- Ghrelin (Ghrl) is an orexigenic peptide with potential roles in the modulation of anxiety- and depressive-like symptoms induced by bilateral olfactory bulbectomy (OB) in rodents. In the present work, we assessed whether intrahippocampal Ghrl could reverse OB-induced depressive-like and amnesic effects by regulating molecular mechanisms related to neuroplasticity. Adult female albino Swiss mice were divided into sham and OB groups, and infused with saline (S) or Ghrl 0.03 nmol/μl, 0.3 nmol/μl, or 3 nmol/μl into the hippocampus before exposition to open-field test (OFT) and tail suspension test (TST) or immediately after training in the object recognition test (ORT). After test phase in ORT, animals were euthanized and their hippocampi were dissected to study the expression of genes related to memory. The OB-S animals presented hyperlocomotion in OFT, increased immobility in TST and memory impairment compared to sham-S (p < 0.05), but acute intrahippocampal infusion of Ghrl 0.3 nmol/μl produced an improvement on these parameters in OB animals (p < 0.05). In addition, this dose of Ghrl reversed OB-induced low expression of NMDA1 and MAPK1 iso1 and up-regulated the expression of CaMKIIa iso1 and iso2, and MAPK1 iso2 (p < 0.05). These results extend the existing literature regarding OB-induced behavioral and neurochemical changes, and provide mechanisms that could underlie the antidepressant effect of Ghrl in this model.
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| 4. |
- de la Villarmois, Emilce, et al.
(författare)
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Pharmacological NOS-1 Inhibition Within the Hippocampus Prevented Expression of Cocaine Sensitization : Correlation with Reduced Synaptic Transmission
- 2020
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Ingår i: Molecular Neurobiology. - : Springer Science and Business Media LLC. - 0893-7648 .- 1559-1182. ; 57:1, s. 450-460
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Tidskriftsartikel (refereegranskat)abstract
- Behavioral sensitization to psychostimulants hyperlocomotor effect is a useful model of addiction and craving. Particularly, cocaine sensitization in rats enhanced synaptic plasticity within the hippocampus, an important brain region for the associative learning processes underlying drug addiction. Nitric oxide (NO) is a neurotransmitter involved in both, hippocampal synaptic plasticity and cocaine sensitization. It has been previously demonstrated a key role of NOS-1/NO/sGC/cGMP signaling pathway in the development of cocaine sensitization and in the associated enhancement of hippocampal synaptic plasticity. The aim of the present investigation was to determine whether NOS-1 inhibition after development of cocaine sensitization was able to reverse it, and to characterize the involvement of the hippocampus in this phenomenon. Male Wistar rats were administered only with cocaine (15 mg/kg/day i.p.) for 5 days. Then, animals received 7-nitroindazole (NOS-1 inhibitor) either systemically for the next 5 days or a single intra-hippocampal administration. Development of sensitization and its expression after withdrawal were tested, as well as threshold for long-term potentiation in hippocampus, NOS-1, and CREB protein levels and gene expression. The results showed that NOS-1 protein levels and gene expression were increased only in sensitized animals as well as CREB gene expression. NOS-1 inhibition after sensitization reversed behavioral expression and the highest level of hippocampal synaptic plasticity. In conclusion, NO signaling within the hippocampus is critical for the development and expression of cocaine sensitization. Therefore, NOS-1 inhibition or NO signaling pathways interferences during short-term withdrawal after repeated cocaine administration may represent plausible pharmacological targets to prevent or reduce susceptibility to relapse.
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| 5. |
- 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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