The Experts below are selected from a list of 444 Experts worldwide ranked by ideXlab platform
Hernan E Lara - One of the best experts on this subject based on the ideXlab platform.
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evidence for a Celiac Ganglion ovarian kisspeptin neural network in the rat intraovarian anti kisspeptin delays vaginal opening and alters estrous cyclicity
Endocrinology, 2012Co-Authors: Manuel Ricu, Victor D Ramirez, Alfonso Paredes, Hernan E LaraAbstract:Kisspeptin and its receptor GPR54 have been described as key hypothalamic components in the regulation of GnRH secretion. Kisspeptin is also present in several regions of the central nervous system and the peripheral organs and has recently been identified in the superior Ganglion. Herein, we tested the possibility that ovarian kisspeptin is regulated by the sympathetic nervous system and participates locally in the regulation of ovarian function. Both ovarian and Celiac Ganglion kisspeptin mRNA levels increase during development, whereas kisspeptin peptide levels and plasma levels decrease during development. In the Celiac Ganglion, kisspeptin colocalized with tyrosine hydroxylase, indicating potential kisspeptin synthesis and transport within the sympathetic neurons. A continuous (64 h) cold stress induced marked changes within the kisspeptin neural system along the Celiac Ganglion-ovary axis. In vitro incubation with the β-adrenergic agonist isoproterenol increased ovarian kisspeptin mRNA and peptide l...
Victor D Ramirez - One of the best experts on this subject based on the ideXlab platform.
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evidence for a Celiac Ganglion ovarian kisspeptin neural network in the rat intraovarian anti kisspeptin delays vaginal opening and alters estrous cyclicity
Endocrinology, 2012Co-Authors: Manuel Ricu, Victor D Ramirez, Alfonso Paredes, Hernan E LaraAbstract:Kisspeptin and its receptor GPR54 have been described as key hypothalamic components in the regulation of GnRH secretion. Kisspeptin is also present in several regions of the central nervous system and the peripheral organs and has recently been identified in the superior Ganglion. Herein, we tested the possibility that ovarian kisspeptin is regulated by the sympathetic nervous system and participates locally in the regulation of ovarian function. Both ovarian and Celiac Ganglion kisspeptin mRNA levels increase during development, whereas kisspeptin peptide levels and plasma levels decrease during development. In the Celiac Ganglion, kisspeptin colocalized with tyrosine hydroxylase, indicating potential kisspeptin synthesis and transport within the sympathetic neurons. A continuous (64 h) cold stress induced marked changes within the kisspeptin neural system along the Celiac Ganglion-ovary axis. In vitro incubation with the β-adrenergic agonist isoproterenol increased ovarian kisspeptin mRNA and peptide l...
Lara Peñaloza Hernán - One of the best experts on this subject based on the ideXlab platform.
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Evidence for a Celiac Ganglion-ovarian kisspeptin neural network in the rat: Intraovarian anti-kisspeptin delays vaginal opening and alters estrous cyclicity
'The Endocrine Society', 2012Co-Authors: Ricu, Manuel A., Ramirez, Victor D., Paredes, Alfonso H., Lara Peñaloza HernánAbstract:Kisspeptin and its receptor GPR54 have been described as key hypothalamic components in the regulation of GnRH secretion. Kisspeptin is also present in several regions of the central nervous system and the peripheral organs and has recently been identified in the superior Ganglion. Herein, wetested the possibility that ovarian kisspeptin is regulated by the sympathetic nervous systemand participates locally in the regulation of ovarian function. Both ovarian and Celiac Ganglion kisspeptin mRNA levels increase during development, whereas kisspeptin peptide levels and plasma levels decrease during development. In the Celiac Ganglion, kisspeptin colocalized with tyrosine hydroxylase, indicating potential kisspeptin synthesis and transport within the sympathetic neurons. A continuous (64 h) cold stress induced marked changes within the kisspeptin neural system along the Celiac Ganglion-ovary axis. In vitro incubation with the β-adrenergic agonist isoproterenol increased ovarian kisspepti
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Functional development of the ovarian noradrenergic innervation
'The Endocrine Society', 2008Co-Authors: Ricu Manuel, Paredes Alfonso, Greiner Monika, Ojeda, Sergio R., Lara Peñaloza HernánAbstract:A substantial fraction of the noradrenergic innervation targeting the mammalian ovary is provided by neurons of the Celiac Ganglion. Although studies in the rat have shown that noradrenergic nerves reach the ovary near the time of birth, it is unknown how the functional capacity of this innervation unfolds during postnatal ovarian development. To address this issue, we assessed the ability of the developing ovary to incorporate and release 3H- norepinephrine. Incorporation of 3H-norepinephrine was low during the first 3 wk of postnatal life, but pharmacological inhibition of norepinephrine (NE) neuronal uptake with cocaine showed that an intact transport mechanism for NE into nerve terminals is already in place by the first week after birth. Consistent with this functional assessment, the mRNA encoding the NE transporter was also expressed in the Celiac Ganglion at this time. During neonatal-infantile development [postnatal (PN) d 5-20], the spontaneous, vesicle-independent outflow o
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An increased intraovarian synthesis of nerve growth factor and its low affinity receptor is a principal component of steroid-induced polycystic ovary in the rat
'Japan Endocrine Society', 2000Co-Authors: Lara Peñaloza Hernán, Fiedler Temer Jenny, Dissen G. A., Leyton Canales Víctor, Paredes Vargas Alfonso, Fuenzalida Cruz Héctor, Ojeda, Sergio R.Abstract:A form of polycystic ovary (PCO) resembling some aspects of the human PCO syndrome can be induced in rats by a single injection of estradiol valerate (EV). An increase in sympathetic outflow to the ovary precedes, by several weeks, the appearance of cysts, suggesting the involvement of a neurogenic component in the pathology of this ovarian dysfunction. The present study was carried out to test the hypotheses that this change in sympathetic tone is related to an augmented production of ovarian nerve growth factor (NGF), and that this abnormally elevated production of NGF contributes to the formation of ovarian cysts induced by EV. Injection of the steroid resulted in increased intraovarian synthesis of NGF and its low affinity receptor, p75 NGFR. The increase was maximal 30 days after EV, coinciding with the elevation in sympathetic tone to the ovary and preceding the appearance of follicular cysts. Intraovarian injections of the retrograde tracer fluorogold combined with in situ hybridization to detect tyrosine hydroxylase (TH) messenger RNA-containing neurons in the Celiac Ganglion revealed that these changes in NGF/p75 NGFR synthesis are accompanied by selective activation of noradrenergic neurons projecting to the ovary. The levels of RBT2 messenger RNA, which encodes a beta-tubulin presumably involved in slow axonal transport, were markedly elevated, indicating that EV-induced formation of ovarian cysts is preceded by functional activation of Celiac Ganglion neurons, including those innervating the ovary. Intraovarian administration of a neutralizing antiserum to NGF in conjunction with an antisense oligodeoxynucleotide to p75 NGFR, via Alzet osmotic minipumps, restored estrous cyclicity and ovulatory capacity in a majority of EV-treated rats. These functional changes were accompanied by restoration of the number of antral follicles per ovary that had been depleted by EV and a significant reduction in the number of both precystic follicles and follicular cysts. The results indicate that the hyperactivation of ovarian sympathetic nerves seen in EV-induced PCO is related to an overproduction of NGF and its low affinity receptor in the gland. They also suggest that activation of this neurotrophic-neurogenic regulatory loop is a component of the pathological process by which EV induces cyst formation and anovulation in rodents. The possibility exists that a similar alteration in neurotrophic input to the ovary contributes to the etiology and/or maintenance of the PCO syndrome in humans
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Stress promotes development of ovarian cysts in rats: The possible role of sympathetic nerve activation
'Springer Science and Business Media LLC', 1998Co-Authors: Paredes Alfonso, Gálvez Anita, Leyton Victor, Aravena Gabriel, Fiedler Temer Jenny, Bustamante Diego, Lara Peñaloza HernánAbstract:Activation of the sympathetic innervation precedes the induction of polycystic ovaries in rats given estradiol valerate (EV). The mechanism of induction by EV may thus involve both direct and neurogenic components. We tested this hypothesis using a combined cold and restraint stress to induce an increase in sympathetic tone, including that of the ovarian sympathetic nerves. Three weeks after the start of stress we found: 1. An increase in the content of norepinephrine (NE) in the Celiac Ganglion. 2. An increase in the release of NE from the ovary. 3. An unchanged NE uptake by the ovary. 4. An unchanged content of NE in the ovary. The ovarian content of neuropeptide Y (NPY) (colocalized with NE) was significantly decreased. These results suggest that NE synthesis and its secretion are increased during this period and correlate with the increase in secretion of androgens and estradiol, the development of precystic follicles, and a decrease in the ovulatory rate. After 11 wk, NE release
Shyam Varadarajulu - One of the best experts on this subject based on the ideXlab platform.
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eus guided Celiac Ganglion radiofrequency ablation versus Celiac plexus neurolysis for palliation of pain in pancreatic cancer a randomized controlled trial with videos
Gastrointestinal Endoscopy, 2019Co-Authors: Ji Young Bang, Bryce Sutton, Robert H Hawes, Shyam VaradarajuluAbstract:Background and Aims Although EUS-guided Celiac plexus neurolysis (EUS-CPN) is frequently performed, its efficacy for palliation of pain in pancreatic cancer is suboptimal. Recently, EUS-guided radiofrequency ablation (EUS-RFA) has been proposed as a palliative treatment option for pancreatic neoplasms. We performed a single-blind, randomized trial to compare the effectiveness of EUS-CPN and EUS-RFA for palliation of pain in pancreatic cancer. Methods Patients with abdominal pain because of locally advanced or metastatic pancreatic cancer underwent EUS-CPN (n = 14) or EUS-RFA (n = 12). EUS-RFA was performed using a 1F monopolar probe passed via a 19-gauge FNA needle, by targeting the area of Celiac plexus or visualized ganglia. Primary outcome was pain severity as measured by the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire pancreatic cancer module (PAN26) administered pretreatment and at 2 and 4 weeks post-treatment. Secondary outcome measures were comparison of quality of life as determined by the PAN26 and EORTC Quality of Life Questionnaire core questionnaire (C30) and opioid analgesia use between the 2 groups. Results Both the PAN26 (49.0 vs 57.0, P Conclusions Compared with EUS-CPN, EUS-RFA provided more pain relief and improved the quality of life for patients with pancreatic cancer. (Clinical trials registration number: NCT03152487.)
A Surprenant - One of the best experts on this subject based on the ideXlab platform.
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potassium currents and their modulation by muscarine and substance p in neuronal cultures from adult guinea pig Celiac ganglia
Journal of Neurophysiology, 1993Co-Authors: S Vanner, Steven G Matsumoto, R J Evans, A SurprenantAbstract:1. Intracellular microelectrode and whole-cell patch-clamp recordings were obtained from adult guinea pig Celiac Ganglion neurons grown in tissue culture for 7-14 days. Over 90% of neurons showed phasic-type action-potential discharge with the use of either type of recording electrode; they stained immunohistochemically for catecholamines, tyrosine hydroxylase, and neuropeptide Y. Input resistance (140 M omega) and action-potential amplitude (103 mV) were significantly greater with whole-cell than with microelectrode recordings, but other passive electrical properties were similar. 2. Five potassium currents were characterized: an apamin-sensitive after hyperpolarizing current (IAHP), an apamin and tetraethylammonium-insensitive slow IAHP, an M-like current, a transient outward IA current, and a delayed rectifier IK current. A hyperpolarization-activated cationic Ih current was also present. The first three currents were not observed with whole-cell recordings. 3. Cadmium (200 microM), cobalt (1 mM), lanthanum (30 microM), or a low calcium/high magnesium solution blocked both IAHPS and the M-like current; barium (1 mM) also blocked these currents. 4. Kinetics of the M-like current were best described by a double exponential fit to deactivating tail currents with time constants of 50 and 390 ms at -50 mV. The apamin-sensitive and slow IAHP decayed exponentially with time constants of 145 ms and 3.5 s, respectively. There was no correlation between occurrence of M-like current (95% of neurons) and slow IAHP (40% of neurons), nor any correlation between magnitude of M-like current and IAHP in those cells exhibiting both currents. 5. Muscarine and substance P (SP) caused depolarizations or inward currents (under voltage clamp) at the resting potential (-55 mV) associated with a decreased membrane conductance. The slow IAHP and the M-like current, but not the apamin-sensitive IAHP nor the IA, were blocked by muscarine and SP (IC50 3 microM and 100 nM, respectively). Muscarine and SP also decreased a "leak" potassium current. 6. We conclude that Celiac neurons express two calcium-dependent IAHP currents and a calcium-dependent M-current; these are seen by fine-tipped intracellular microelectrodes but not by whole-cell patch electrodes. These currents are not required for spike frequency accommodation. Muscarine and SP reduce these currents, as well as voltage-independent leakage potassium current.