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1.
Phys Rev Lett ; 132(17): 171001, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38728703

RESUMO

Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15 keV/c^{2}, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/c^{2} is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.

2.
Zhonghua Wai Ke Za Zhi ; 62(1): 50-57, 2023 Dec 01.
Artigo em Chinês | MEDLINE | ID: mdl-38044608

RESUMO

Objectives: To investigate the early related factors for hepatic insufficiency after hemihepatectomy and to construct and validate a nomogram model. Methods: This was a retrospective cohort study.There were 207 patients with liver tumor who underwent hemihepatectomy in the Department of Hepatobiliary Surgery,Cancer Hospital,Chinese Academy of Medical Sciences from October 2016 to December 2022. Using the random number method,patients were randomly divided into a model group(n=166) and a validation group(n=41) according to an 4︰1 ratio. There were 118 males and 48 females in the modeling group,with an age (M(IQR)) of 59.0(13.3) years (range: 22.0 to 81.0 years),42 patients in the group with postoperative liver insufficiency and 124 patients in the group without postoperative liver insufficiency. There were 32 males and 9 females in the validation group, with an age of 54.0(19.0) years (rang: 25.0~81.0 years). The first results of the peripheral blood test of patients within 24 hours after surgery were collected,and the independent related factors for incomplete postoperative liver function were determined by multivariate Logistic regression analysis,and related factors of postoperative incomplete liver function were screened by best subset selection. A nomogram model of the risk of postoperative hepatic insufficiency after hemihepatectomy was constructed using R software,followed by internal and external validation of the model. Results: Multivariate logistic regression analysis showed that elevated D-dimer level and decreased antithrombin Ⅲ (AT-Ⅲ) activity within 24 hours after surgery were independent related factors for the development of postoperative hepatic insufficiency in hemihepatectomized patients. The results of the best subset selection showed that ALT,D-dimer, and AT-Ⅲ activity levels within 24 hours postoperatively were the most relevant factors for postoperative hepatic insufficiency. The R software was applied to build a nomogram prediction model based on the above three indicators in the model set,and the receiver operating characteristic(ROC) curve of the model showed an area under the curve of 0.803 and the calibration curve showed a U-index of -0.012 for the model(P=0.977). The results of the clinical decision analysis and the clinical impact curve indicated that the model had good clinical utility. The internal validation results of the Bootstrap method suggested that the model had reasonable consistency. The area under the ROC curve of the validation group model was 0.806,suggesting that the model had a good generalization prediction ability. Conclusions: The levels of ALT,D-dimer,and AT-Ⅲ activity within 24 hours after hemihepatectomy are valuable indicators for predicting liver insufficiency after hemihepatectomy. The nomogram model is reliable and can be used as an indicator for close postoperative monitoring.

3.
Phys Rev Lett ; 129(22): 221301, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493436

RESUMO

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4 kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80 MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90 MeV/c^{2} with heavy mediators and m_{χ} larger than 100 MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.


Assuntos
Eletricidade , Elétrons
4.
Phys Rev Lett ; 129(22): 221802, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493447

RESUMO

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46} cm^{2} (90% C.L.) at DM mass of 10 MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14 MeV/c^{2} for the massless dark photon and bound DM final state, respectively.


Assuntos
Núcleo Celular , Fótons
5.
Phys Rev Lett ; 124(11): 111301, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32242731

RESUMO

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300 eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0 keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200 eV/c^{2}.

6.
Mol Cell Endocrinol ; 500: 110629, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31678419

RESUMO

Reproduction and growth are under multifactorial control of neurohormones and peripheral hormones. This study investigated seasonally related effects of GnIH, GnRH, and T3 on the reproductive and growth axis in male goldfish at three stages of gonadal recrudescence. The effects of injection treatments with GnRH, GnIH and/or T3 were examined by measuring serum LH and GH levels, as well as peripheral transcript levels, using a factorial design. As expected, GnRH elevated serum LH and GH levels in a seasonally dependant manner, with maximal elevations of LH in late stages of gonadal recrudescence (Spring) and maximal increases in GH in the regressed gonadal stage (Summer). GnIH injection increased serum LH and GH levels only in fish at the regressed stage but exerted both stimulatory and inhibitory effects on GnRH-induced LH responses depending on season. T3 treatment mainly had stimulatory effects on circulating LH levels and inhibitory effects on serum GH concentrations. In the liver and testes, we observed seasonal differences in thyroid receptors, estrogen receptors, vitellogenin, follicle-stimulating hormone receptor, aromatase and IGF-I transcript levels that were tissue- and sex-specific. Generally, there were no clear correlation between circulating LH and GH levels and peripheral transcript levels, presumably due to time-related response and possible direct interaction of GnRH and GnIH at the level of liver and testis. The results support the hypothesis that GnRH and GnIH are important components of multifactorial mechanisms that work in concert with T3 to regulate reciprocal control of reproduction and growth in goldfish.


Assuntos
Carpa Dourada/fisiologia , Hormônio Liberador de Gonadotropina/administração & dosagem , Neuropeptídeos/administração & dosagem , Tri-Iodotironina/administração & dosagem , Animais , Proteínas de Peixes/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio do Crescimento/sangue , Fígado/metabolismo , Hormônio Luteinizante/sangue , Masculino , Neuropeptídeos/farmacologia , Especificidade de Órgãos , Reprodução , Testículo/metabolismo , Tri-Iodotironina/farmacologia
7.
Phys Rev Lett ; 123(22): 221301, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31868422

RESUMO

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.

8.
Phys Rev Lett ; 123(16): 161301, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31702340

RESUMO

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35} cm^{2} for TI analysis at m_{χ}∼50-180 MeV/c^{2}, and 3×10^{-32}∼9×10^{-38} cm^{2} for AM analysis at m_{χ}∼75 MeV/c^{2}-3.0 GeV/c^{2}.

9.
Phys Rev Lett ; 120(24): 241301, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29956956

RESUMO

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36} cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5 GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2 GeV/c^{2}.

10.
J Endocrinol ; 223(2): 191-202, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25319842

RESUMO

To understand how gonadotropin-inhibitory hormone (GnIH) regulates goldfish GH cell functions, we monitored GH release and expression during early, mid-, and/or late gonadal recrudescence. In vivo and in vitro responses to goldfish (g) GnIH were different, indicating direct action at the level of pituitary, as well as interactions with other neuroendocrine factors involved in GH regulation. Injection of gGnIH consistently reduced basal serum GH levels but elevated pituitary gh mRNA levels, indicating potential dissociation of GH release and synthesis. Goldfish GnRH (sGnRH and cGnRHII) injection differentially stimulated serum GH and pituitary gh mRNA levels with some seasonal differences; these responses were reduced by gGnIH. In contrast, in vitro application of gGnIH during 24-h static incubation of goldfish pituitary cells generally elevated basal GH release and attenuated sGnRH-induced changes in gh mRNA, while suppressing basal gh mRNA levels at mid- and late recrudescence but elevating them at early recrudescence. gGnIH attenuated the GH release responses to sGnRH during static incubation at early, but not at mid- and late recrudescence. In cell column perifusion experiments examining short-term GH release, gGnIH reduced the cGnRHII- and sGnRH-stimulated secretion at late recrudescence but inhibited tha action of cGnRHII only during mid-recrudescence. Interestingly, a reduction of basal GH release upon perifusion with gGnIH during late recrudescence was followed by a rebound increase in GH release upon gGnIH removal. These results indicate that gGnIH exerts complex effects on basal and GnRH-stimulated goldfish GH cell functions and can differentially affect GH release and mRNA expression in a seasonal reproductive manner.


Assuntos
Carpa Dourada/fisiologia , Hormônio Liberador de Gonadotropina/farmacologia , Hormônios Hipotalâmicos/farmacologia , Estações do Ano , Somatotrofos/efeitos dos fármacos , Animais , Células Cultivadas , Feminino , Carpa Dourada/sangue , Hormônio do Crescimento/genética , Hormônio do Crescimento/metabolismo , Masculino , Cultura Primária de Células , Somatotrofos/fisiologia
12.
J Neuroendocrinol ; 25(5): 506-16, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23331955

RESUMO

We have shown that native goldfish gonadotrophin inhibitory hormone (gGnIH) differentially regulates luteinsing hormone (LH)-ß and follicle-stimulating hormone (FSH)-ß expression. To further understand the functions of gGnIH, we examined its interactions with two native goldfish gonadotrophin-releasing hormones, salmon gonadotrophin-releasing hormone (sGnRH) and chicken (c)GnRH-II in vivo and in vitro. Intraperitoneal injections of gGnIH alone reduced serum LH levels in fish in early and mid gonadal recrudescence; this inhibition was also seen in fish co-injected with either sGnRH or cGnRH-II during early recrudescence. Injection of gGnIH alone elevated pituitary LH-ß and FSH-ß mRNA levels at early and mid recrudescence, and FSH-ß mRNA at late recrudescence. Co-injection of gGnIH attenuated the stimulatory influences of sGnRH on LH-ß in early recrudescence, and LH-ß and FSH-ß mRNA levels in mid and late recrudescence, as well as the cGnRH-II-elicited increase in LH-ß, but not FSH-ß, mRNA expression at mid and late recrudescence. sGnRH and cGnRH-II injection increased pituitary gGnIH-R mRNA expression in mid and late recrudescence but gGnIH reduced gGnIH-R mRNA levels in late recrudescence. gGnIH did not affect basal LH release from perifused pituitary cells and continual exposure to gGnIH did not alter the LH responses to acute applications of GnRH. However, a short 5-min GnIH treatment in the middle of a 60-min GnRH perifusion selectively reduced the cGnRH-II-induced release of LH. These novel results indicate that, in goldfish, gGnIH and GnRH modulate pituitary GnIH-R expression and gGnIH differentially affects sGnRH and cGnRH-II regulation of LH secretion and gonadotrophin subunit mRNA levels. Furthermore, these actions are manifested in a reproductive stage-dependent manner.


Assuntos
Carpa Dourada , Hormônio Liberador de Gonadotropina/fisiologia , Gonadotropinas/antagonistas & inibidores , Hipófise/fisiologia , Estações do Ano , Animais , Sequência de Bases , Primers do DNA , Hormônio Foliculoestimulante/genética , Hormônio Luteinizante/sangue , Hormônio Luteinizante/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real
13.
J Neuroendocrinol ; 24(8): 1166-81, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22487215

RESUMO

Nitric oxide synthase (NOS) immunoreactivity is present in goldfish gonadotrophs. The present study investigated whether two native goldfish gonadotrophin-releasing hormones (GnRHs), salmon (s)GnRH and chicken (c)GnRH-II, use NOS/nitric oxide (NO) and soluble guanylate cyclase (sGC)/cyclic (c)GMP/protein kinase G (PKG) signalling to stimulate maturational gonadotrophin [teleost gonadotrophin-II, luteinising hormone (LH)] release. In cell column perifusion experiments with dispersed goldfish pituitary cells, the application of three NOS inhibitors (aminoguanidine hemisulphate, 1400W and 7-nitroindazole) and two NO scavengers [2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) and rutin hydrate] reduced sGnRH-elicited, but not cGnRH-II-induced, LH increases. The NO donor sodium nitroprusside (SNP) increased NO production in goldfish pituitary cells in static incubation. SNP-stimulated LH release in column perifusion was attenuated by PTIO and the sGC inhibitor 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-oneon (ODQ), and additive to responses elicited by cGnRH-II, but not sGnRH. ODQ and the PKG inhibitor KT5823 decreased sGnRH- and cGnRH-II-stimulated LH release. Similarly, the LH response to dibutyryl cGMP was reduced by KT5823. These results indicate that, although only sGnRH uses the NOS/NO pathway to stimulate LH release, both GnRHs utilise sGC/PKG to increase LH secretion.


Assuntos
Hormônio Liberador de Gonadotropina/fisiologia , Guanilato Ciclase/metabolismo , Hormônio Luteinizante/metabolismo , Óxido Nítrico/metabolismo , Hipófise/metabolismo , Transdução de Sinais , Animais , Carbazóis/farmacologia , Feminino , Carpa Dourada , Guanilato Ciclase/antagonistas & inibidores , Masculino , Óxido Nítrico/biossíntese , Doadores de Óxido Nítrico/farmacologia , Nitroprussiato/farmacologia , Hipófise/citologia , Hipófise/enzimologia , Inibidores de Proteínas Quinases/farmacologia
14.
Mol Cell Endocrinol ; 350(1): 53-60, 2012 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-22155567

RESUMO

Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin release in birds and mammals. To investigate its role in teleosts, we examined the effects of synthetic goldfish (g)GnIH on pituitary LH-ß and FSH-ß subunit, and gGnIH receptor (gGnIH-R) mRNA levels and LH secretion in goldfish. Intraperitoneal injections of gGnIH increased pituitary LH-ß and FSH-ß mRNA levels at early to late gonadal recrudescence, but reduced serum LH and pituitary gGnIH-R mRNA levels, respectively, at early to mid-recrudescence and later stages of recrudescence. Static incubation with gGnIH elevated LH secretion from dispersed pituitary cell cultures from prespawning fish, but not at other recrudescent stages; suppressed LH-ß mRNA levels at early recrudescence and prespawning but elevated LH-ß at mid-recrudescence; and consistently attenuated FSH-ß mRNA in a dose-specific manner. Results indicate that in goldfish, regulation of LH secretion and gonadotropin subunit mRNA levels are dissociated in the presence of gGnIH and dependent on maturational status and administration route.


Assuntos
Proteínas de Peixes/fisiologia , Gonadotrofos/fisiologia , Hormônios Hipotalâmicos/fisiologia , Hipófise/citologia , Animais , Células Cultivadas , Feminino , Proteínas de Peixes/metabolismo , Proteínas de Peixes/farmacologia , Subunidade beta do Hormônio Folículoestimulante/genética , Subunidade beta do Hormônio Folículoestimulante/metabolismo , Regulação da Expressão Gênica , Carpa Dourada , Gonadotrofos/metabolismo , Gônadas/fisiologia , Hormônios Hipotalâmicos/farmacologia , Hormônio Luteinizante Subunidade beta/sangue , Hormônio Luteinizante Subunidade beta/genética , Hormônio Luteinizante Subunidade beta/metabolismo , Masculino , Hipófise/metabolismo , Cultura Primária de Células , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Fenômenos Reprodutivos Fisiológicos , Estações do Ano , Transcrição Gênica
15.
J Neuroendocrinol ; 23(12): 1273-87, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21919972

RESUMO

Ghrelin (GRLN) and its receptor have been identified and characterised in goldfish brain and the pituitary, and recent evidence shows that goldfish (g)GRLN(19) induces both growth hormone (GH) and maturational gonadotrophin (LH) release through an extracellular Ca(2+) -dependent mechanism in goldfish. To further understand the role of GRLN in hormone release, the present study examined the involvement of protein kinase C (PKC) and protein kinase A (PKA) in gGRLN(19) -induced GH and LH release and corresponding Ca(2+) signals in primary cultures of goldfish pituitary cells. Treatments with PKC inhibitors, Bis-II and Gö 6976, significantly reduced gGRLN(19) -induced GH and LH release and their corresponding intracellular Ca(2+) signals in identified somatotrophs and gonadotrophs, respectively. gGRLN(19) was unable to further stimulate hormone release or Ca(2+) signals when cells were pretreated with the PKC agonist, DiC8. PKA inhibitors, H-89 and KT 5720, inhibited gGRLN(19) -induced LH release and Ca(2+) signals in gonadotrophs but not GH release or Ca(2+) signals in somatotrophs. Interestingly, pretreatment of pituitary cells with the adenylate cyclase activator forskolin potentiated gGRLN(19) -induced GH, but not LH, release, although it had no effect on intracellular Ca(2+) signals in either cell type. Taken together, the results suggest that PKC is an important intracellular component in gGRLN(19) -induced GH and LH release, whereas PKA is involved in gGRLN(19) -elicited LH release. Furthermore, the PKA pathway potentiates gGRLN(19) -induced GH release via a Ca(2+) -independent mechanism. Overall, the present study provides insight into the neuroendocrine regulation of GH and LH release by elucidating the mechanistic aspects of GRLN, a hormone involved in many critical physiological processes, including pituitary functions.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Grelina/farmacologia , Gonadotropinas/metabolismo , Hormônio do Crescimento/metabolismo , Hipófise/metabolismo , Proteína Quinase C/fisiologia , Animais , Cálcio/metabolismo , Carbazóis/farmacologia , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Diglicerídeos/farmacologia , Feminino , Grelina/química , Carpa Dourada , Isoquinolinas/farmacologia , Masculino , Hipófise/efeitos dos fármacos , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Sulfonamidas/farmacologia
16.
J Neuroendocrinol ; 23(4): 302-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21276102

RESUMO

Previous microarray analyses of the goldfish hypothalamus led us to hypothesise that dopamine could potentially inhibit the excitatory effects of glutamate on luteinising hormone (LH). Post-spawning female goldfish were pre-treated (-4.5 h) with either saline (C; control), SCH 23390 (S; D(1) -receptor antagonist) or sulpiride (L; D(2) -receptor antagonist), followed by an i.p. injection, at -0.5 h, of saline or the glutamate agonist AMPA (A, SA or LA). Blood, hypothalamus and telencephalon tissues were collected. Serum LH was not affected in the S, L, A, or LA groups relative to control as determined by radioimmunoassay. The SA group, however, showed a 289% (P<0.0005) increase in serum LH compared to either treatment alone or control. Real-time reverse transcriptase-polymerase chain reaction identified the mRNAs for ionotropic (Gria2a, Gria4) glutamate receptor subunits, activin ßa, isotocin, and cGnRH-II as being significantly affected by some of the treatments. The same experiment conducted with sexually-regressed female fish showed a very different LH profile, indicating that this mechanism is seasonally-dependent. We also show that i.p. injection of 1 µg/g isotocin was able to increase LH levels by 167% in sexually regressed female fish relative to controls. Taken together, these results demonstrate that blockage of the D(1) receptor primes post-spawning goldfish for AMPA-stimulated LH release, and provides further insights into the central regulation of reproduction.


Assuntos
Carpa Dourada/fisiologia , Hipotálamo/efeitos dos fármacos , Hormônio Luteinizante/metabolismo , Receptores de Dopamina D1/antagonistas & inibidores , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia , Animais , Benzazepinas/farmacologia , Antagonistas de Dopamina/farmacologia , Feminino , Carpa Dourada/anatomia & histologia , Hipotálamo/citologia , Hipotálamo/metabolismo , Hormônio Luteinizante/sangue , Ocitocina/análogos & derivados , Ocitocina/farmacologia , Reprodução/efeitos dos fármacos , Reprodução/fisiologia , Sulpirida/farmacologia
17.
J Neuroendocrinol ; 23(1): 82-93, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20874777

RESUMO

Message encoding for three isoforms of somatostatin (SS) peptides, SS-14, goldfish brain (gb)SS-28 and [Pro²]SS-14, are expressed in goldfish hypothalamus and pituitary tissues. All three native goldfish SSs are active in reducing basal and stimulated growth hormone (GH) responses in cultured goldfish pituitary cells, although with different potencies and efficacies. In the present study, we examined the effects of these three endogenous SSs on electrophysiological properties of goldfish somatotrophs and their physiological relevance. Voltage-sensitive K+ , Ca²+ and Na+ channels in identified goldfish somatotrophs in primary culture were isolated using whole-cell, amphotericin B-perforated patch-clamp techniques. None of the three SSs affected Na+ currents but all three SSs increased maximal K+ current magnitude, with SS-14 being the most effective. [Pro²]SS14 did not affect Ba²+ currents through voltage-sensitive Ca²+ channels but SS14 decreased the magnitude of early and late Ba²+ currents, whereas gbSS-28 reduced that of the late Ba²+ current. Under current-clamp conditions, SS14 and gbSS28 attenuated evoked action potential magnitudes by 34% and 18%, respectively, although [Pro²]SS14 had no effects. However, all three SSs decreased basal intracellular Ca²+ levels ([Ca²+ ](i)) and suppressed basal GH release. These data suggest that, although the ability of SS-14 and gbSS-28 to decrease basal [Ca²+](i) and GH release can be explained, at least in part, by their attenuating effects on cell excitability and current flow through voltage-sensitive Ca²+ channels, [Pro²]SS14-induced reduction in GH responses and [Ca²+](i) cannot be explained by changes in Ca²+ channel properties.


Assuntos
Potenciais da Membrana/efeitos dos fármacos , Isoformas de Proteínas/farmacologia , Somatostatina/farmacologia , Somatotrofos/fisiologia , Animais , Feminino , Carpa Dourada , Masculino , Técnicas de Patch-Clamp
19.
Eur Surg Res ; 45(2): 98-104, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20847567

RESUMO

BACKGROUND: Atrial enlargement occurs in patients with significant mitral regurgitation. However, the time frame of the development of atrial enlargement induced by mitral regurgitation remains unknown. METHODS: Fourteen Lanyu miniature pigs (age = 6.6 ± 0.9 months) were studied. Mitral regurgitation was created by placing a predefined hole on the middle scallop of the posterior mitral leaflet under cardiopulmonary bypass. The parasternal long-axis atrial dimension was measured by transthoracic echocardiographic examinations. RESULTS: All animals exhibited grade 3 mitral regurgitation immediately after surgery. Seven pigs expired within 2 weeks after the operation [technical complications (n = 1), acute cardiac tamponade (n = 1), and acute and subacute heart failure (n = 5)]. Seven pigs remained alive at a mean follow-up of 7.7 ± 2.1 months. The left atrial diameter indices of the 7 pigs increased significantly at 1 month (33.1 ± 8.6 mm, p = 0.018) and 3 months (41.3 ± 12.6 mm, p = 0.018) after surgery compared with baseline values (22.8 ± 5.2 mm), and the left atrial diameter index increased significantly at 3 months compared to 1 month (p = 0.018). CONCLUSIONS: Left atrial enlargement develops rapidly and progresses after the creation of significant pure mitral regurgitation.


Assuntos
Cardiomegalia/etiologia , Insuficiência da Valva Mitral/complicações , Animais , Cardiomegalia/diagnóstico por imagem , Cardiomegalia/patologia , Cardiomegalia/fisiopatologia , Modelos Animais de Doenças , Ecocardiografia Doppler em Cores , Feminino , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Hemodinâmica , Humanos , Masculino , Insuficiência da Valva Mitral/fisiopatologia , Suínos , Porco Miniatura , Fatores de Tempo
20.
Gen Comp Endocrinol ; 168(1): 71-81, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20403359

RESUMO

Goldfish brain somatostatin-28 (gbSS-28) is present in brain and pituitary tissues of goldfish. We assessed whether gbSS-28 targets Ca(2+) and/or protein kinase C (PKC)-dependent signaling cascades in inhibiting growth hormone (GH) release. gbSS-28 decreased basal GH release from primary cultures of dispersed goldfish pituitary cells and intracellular free calcium levels ([Ca(2+)](i)) in goldfish somatotropes. gbSS-28 partially reduced [Ca(2+)](i) and GH responses induced by two endogeneous gonadotropin-releasing hormones (GnRHs), salmon (s)GnRH and chicken (c)GnRH-II. Furthermore, gbSS-28 reduced GH increases and abolished [Ca(2+)](i) elevations elicited by two PKC activators, tetradecanoyl 4beta-phorbol-13-acetate and dioctanyl glycerol. The PKC inhibitors Gö6976 and Bis II abolished [Ca(2+)](i) responses to PKC activators, but only attenuated GnRH-induced increases in [Ca(2+)](i) and did not alter basal [Ca(2+)](i). In cells pretreated with Bis II, gbSS-28 further reduced basal [Ca(2+)](i). Our results suggest that gbSS-28 inhibits GnRH-induced GH release in part by attenuating PKC-mediated GnRH [Ca(2+)](i) signals. gbSS-28 reduces basal GH release also via reduction in [Ca(2+)](i) but PKC is not involved in this regard.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Cálcio/metabolismo , Carpa Dourada/metabolismo , Hormônio do Crescimento/metabolismo , Proteína Quinase C/metabolismo , Somatostatina-28/farmacologia , Animais , Células Cultivadas , Hormônios/farmacologia , Transdução de Sinais/efeitos dos fármacos
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