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1.
West Afr J Med ; 40(11 Suppl 1): S4, 2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37970780

RESUMEN

Introduction: Tuberculosis (TB) was the leading cause of death from an infectious agent worldwide, until the Coronavirus (COVID-19) pandemic, ranking above HIV/AIDS. Nigeria ranks 6th among the 30 TB high-burden countries (TB, TB/HIV, DRTB) and 1st in Africa. The estimated case fatality rate (CFR) of TB in Sub-Sahara Africa (SSA) is 15%. Objective: To review the Tuberculosis case fatality rate (TCFR) in children diagnosed with TB from 2000-2019 in Federal Teaching Hospital Gombe. Methodology: All cases of Tuberculosis (TB) diagnosed in children using ICD 10 classification were retrieved and analyzed. These included deaths from TB. The mainstay of TB diagnosis was clinical using TB Score (81%), Gene Xpert was 7%, and AFB was 10%. Results: 26,716 children were admitted; 383 had TB out of which 208(54.3%) were males and 175 (45.7%) females. TB constituted 1.4% of Paediatric admissions. Children 0 -5 years constituted 46.7% (179/383) of cases and 11 - 18 years were 31.3% (120/383). Fulani, Hausa, and Tangale constituted 43.6% (167), 21.1% (81), and 6.8% (26) of TB cases respectively. TB admissions were highest between 2015 and 2019 (31.8%). TB adenitis was the most common extrapulmonary TB. Tuberculosis/HIV co-infection accounted for 103(27%), out of which 74% (44) died. Overall TCFR was 15.6%; TCFR was 16.3% in males and 14.8% in females. The TCFR was 46.7% in 0-5yrs; 15% in 6-9yrs and 38.3% in 10-18yrs.Fulani had the highest CFR (11.9%). Tuberculosis CFR was highest between 2010-2014 (30.0%) and lowest in 2005-2009 (21.6%). Conclusion: The Tuberculosis CFR is comparable to SSA CFR.


Asunto(s)
Infecciones por VIH , Tuberculosis , Masculino , Femenino , Niño , Humanos , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Infecciones por VIH/epidemiología , Hospitales de Enseñanza , África del Sur del Sahara , Hospitalización
2.
West Afr J Med ; 37(4): 402-406, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32835403

RESUMEN

BACKGROUND: Preterm babies have constituted a major constraints on human and material resources due to early mortality and long term disability among survivors. Rates of disability among survivors have increased over the period, with high rates of broncho-pulmonary dysplasia. OBJECTIVE: To determine the survival and management challenges of preterm babies in University of Maiduguri Teaching Hospital, Maiduguri Borno State REUSLTS: Of the 1129 preterm babies managed in the Special Care Baby Unit (SCBU), 714 cases notes were retrieved and analyzed giving a retrieval rate of 63%. There were 256 (35.9%) preterm babies as in-born, while 458 (64.1%) were out-born. Male preterm babies were 372 (52.1%), while female preterm babies were 342 (47.9%); with female to male ratio of 1.08:1. Extreme low birth weight (<1000grams) were 17 (2.3%), very low birth weight (1000-1499 grams) were 288 (40.3%) while low birth weight (1500-2499 grams) were 406 (56.9%). We also documented 3 preterm babies whose weights >2500 grams were large for gestational age weight. Duration of oxygen therapy (p = 0.620), duration of phototherapy (p = 0.474), and EBT (p = 0.466) showed no association with their survival while only duration of incubator care (p = 0.005) demonstrated significant association with outcome. CONCLUSION: The population of preterm babies studied is 32.70% and their survival has remarkably improved. However, this improved survival of preterm babies especially the extreme and very low birth weight categories has posed a big challenge due to limited access to incubator care, use of caffeine and surfactant which might influence the outcome.


Asunto(s)
Recién Nacido de Bajo Peso , Femenino , Edad Gestacional , Hospitales de Enseñanza , Humanos , Lactante , Mortalidad Infantil , Recién Nacido , Masculino , Nigeria
3.
Mol Psychiatry ; 22(12): 1714-1724, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27646265

RESUMEN

Lithium responsivity in patients with bipolar disorder has been genetically associated with Phosphodiesterase 11A (PDE11A), and lithium decreases PDE11A mRNA in induced pluripotent stem cell-derived hippocampal neurons originating from lithium-responsive patients. PDE11 is an enzyme uniquely enriched in the hippocampus that breaks down cyclic AMP and cyclic GMP. Here we determined whether decreasing PDE11A expression is sufficient to increase lithium responsivity in mice. In dorsal hippocampus and ventral hippocampus (VHIPP), lithium-responsive C57BL/6J and 129S6/SvEvTac mice show decreased PDE11A4 protein expression relative to lithium-unresponsive BALB/cJ mice. In VHIPP, C57BL/6J mice also show differences in PDE11A4 compartmentalization relative to BALB/cJ mice. In contrast, neither PDE2A nor PDE10A expression differ among the strains. The compartment-specific differences in PDE11A4 protein expression are explained by a coding single-nucleotide polymorphism (SNP) at amino acid 499, which falls within the GAF-B homodimerization domain. Relative to the BALB/cJ 499T, the C57BL/6J 499A decreases PDE11A4 homodimerization, which removes PDE11A4 from the membrane. Consistent with the observation that lower PDE11A4 expression correlates with better lithium responsiveness, we found that Pde11a knockout mice (KO) given 0.4% lithium chow for 3+ weeks exhibit greater lithium responsivity relative to wild-type (WT) littermates in tail suspension, an antidepressant-predictive assay, and amphetamine hyperlocomotion, an anti-manic predictive assay. Reduced PDE11A4 expression may represent a lithium-sensitive pathophysiology, because both C57BL/6J and Pde11a KO mice show increased expression of the pro-inflammatory cytokine interleukin-6 (IL-6) relative to BALB/cJ and PDE11A WT mice, respectively. Our finding that PDE11A4 negatively regulates lithium responsivity in mice suggests that the PDE11A SNPs identified in patients may be functionally relevant.


Asunto(s)
3',5'-GMP Cíclico Fosfodiesterasas/metabolismo , Resistencia a Medicamentos/fisiología , Carbonato de Litio/farmacología , Psicotrópicos/farmacología , 3',5'-GMP Cíclico Fosfodiesterasas/genética , Animales , Células COS , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Chlorocebus aethiops , Resistencia a Medicamentos/genética , Femenino , Expresión Génica , Células HEK293 , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Humanos , Masculino , Ratones de la Cepa 129 , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Polimorfismo de Nucleótido Simple , Multimerización de Proteína , ARN Mensajero/metabolismo , Especificidad de la Especie
4.
Horm Metab Res ; 47(8): 611-21, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25230326

RESUMEN

Short-term abstinence from food intake, planned or unplanned, is unavoidable in modern life, but negatively correlated with appetite control and obesity. This study investigated the role of estradiol in feeding and body weight (BW) reactions to short-span cessation of feeding. During acute 1-6-h re-feeding, 12-h food-deprived (FD), estradiol benzoate (EB)-implanted ovariectomized rats ate less food and gained less weight than FD animals implanted with oil (O). Full fed (FF)- and FD-EB consumed equal amounts of food over 24 h, but weight gain was greater in the latter; 24-h food intake and BW gain in FD-O exceeded FD-EB. Caudal fourth ventricular administration of the AMPK activator AICAR increased dorsal vagal complex AMPK activity in FD-EB and FD-O, but elicited dissimilar adjustments in hypothalamic metabolic neuropeptide transmitter expression, while respectively enhancing or reducing acute re-feeding in these animals and reversing FD-O weight gain. Drug-treated FD-EB and FD-O exhibited respective feeding and weight gain increases between 6-24 h. AICAR enhanced 24-h consumption in FD-EB vs. FF-EB, but cumulative intake and BW gain were greater in AICAR-treated FD-O vs. FD-EB. Results show that estradiol limits acute re-feeding after short-term feeding suspension, but augments acute re-feeding when energy depletion coincides with suspended feeding. This compound metabolic stress exerts steroid-dependent effects during later resumption of circadian-induced feeding, for example, increased consumption vs. weight gain in the presence vs. absence of estradiol. These studies provide novel evidence that estrogen mitigates acute and post-acute adverse effects of disrupted fuel acquisition on energy balance.


Asunto(s)
Conducta Animal/fisiología , Estradiol/análogos & derivados , Estradiol/fisiología , Estrógenos/fisiología , Conducta Alimentaria/fisiología , Privación de Alimentos/fisiología , Aumento de Peso/fisiología , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Animales , Conducta Animal/efectos de los fármacos , Peso Corporal , Estradiol/administración & dosificación , Conducta Alimentaria/efectos de los fármacos , Femenino , Hipoglucemiantes/farmacología , Ovariectomía , Ratas , Ratas Sprague-Dawley , Ribonucleótidos/farmacología , Aumento de Peso/efectos de los fármacos
5.
West Afr J Med ; 31(4): 243-6, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23468026

RESUMEN

BACKGROUND: Infants are protected from measles infection by maternal measles antibodies (MMA). The level of these MMA at birth in newborn children depends on the levels in their mother and the extent of placental transfer. We investigated maternal HIV infection as a predictor of levels of MMA in mother-infant pairs in Maiduguri. METHODS: A total of 180 mother-infant pairs were tested for MMA between 15th January and 29th March 2010. Levels of MMA were measured using enzyme linked immunosorbent assay (ELISA) test. RESULTS: Fifteen (8.3%) mothers were found with HIV infection and all were on antiretroviral treatment for HIV, and all of them had protective MMA. Of these mothers with HIV infection, only one (0.6%) of their newborn infants had un-protective level of maternal measles antibody. Maternal measles antibodies in mother-infant pairs had significant correlation (p = 0.005) for both HIV-infected and HIV-uninfected groups. The mean MMA of the newborn children was lower in infants of HIV-infected mothers than in HIV-uninfected mothers (p = 0.37). Linear regression analysis showed no significant association between maternal HIV infection and MMA in mother-infant pairs (p = 0.72) for mothers and (p = 0.37) for newborn infants. CONCLUSION: Maternal HIV infection was not associated with significantly reduced MMA in mother-infant pairs, as high protective levels were evident in both mother-infant pairs at birth.


Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por VIH/inmunología , Recién Nacido/inmunología , Virus del Sarampión/inmunología , Complicaciones Infecciosas del Embarazo/inmunología , Fármacos Anti-VIH/uso terapéutico , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por VIH/tratamiento farmacológico , Hospitales de Enseñanza , Humanos , Intercambio Materno-Fetal , Nigeria , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico
6.
Biol Trace Elem Res ; 123(1-3): 47-57, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18286236

RESUMEN

A comparative evaluation of three washing methods for removing exogenous elemental contamination from fetal scalp hair is described. A total of 12 samples, including 6 from normal pregnancies and 6 from abruptio placentae (AP) cases, were used. Each was divided into four subsamples, with one left unwashed for comparison, while three were subjected to one of the three washing methods. The first consisted of agitating hair for 5 min in sequential and equal measures (30 ml) of acetone and water, followed by rinsing with acetone, and the process repeated twice. In the second and third, hair was agitated for 30 min in aqueous solutions of sodium lauryl sulfate (0.5%, w/v), and Triton X-100 (0.5%, v/v), respectively, followed by sequential rinsing with deionized water and acetone. After drying and microwave-assisted digestion in concentrated nitric acid, the subsamples' concentrations of zinc, copper, cadmium, lead, mercury and selenium were determined using inductively coupled mass spectrometry. All washed subsamples, irrespective of washing method used, had lower elemental concentrations than the corresponding, unwashed subsamples. These differences, taken as presumptive indicators of exogenous contamination, showed only small variations (<5%) between the three washing methods, irrespective of element, mode of delivery, and obstetric outcome. However, the contamination levels elicited by each of the three methods varied in magnitude according to individual elements, with those of copper being highest, followed by those of zinc, cadmium, mercury, selenium, and lead. They also varied according to obstetric outcome, being highest in the AP subsamples, while in the normal pregnancy group, copper and zinc contamination levels in the subsamples from neonates delivered by elective caesarean section were higher than in those from normal-delivery neonates. The data from this study suggest that the three washing methods used have comparable efficacies in removing exogenous elemental contamination from fetal hair, further inferring that it is probably a simple biological matrix to decontaminate. Possible contributory factors are discussed and contrasted with those affecting adult hair.


Asunto(s)
Feto/química , Resultado del Embarazo , Irrigación Terapéutica/métodos , Oligoelementos/aislamiento & purificación , Femenino , Humanos , Espectrometría de Masas , Embarazo
7.
Neuroscience ; 314: 35-46, 2016 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-26628404

RESUMEN

This study addressed the hypothesis that dorsomedial hindbrain adenosine 5'-monophosphate-activated protein kinase (AMPK) imposes inherent estradiol-dependent control of hypothalamic AMPK, neuropeptide, and norepinephrine (NE) activity and feeding in the female rat. Estradiol (E)- or oil (O)-implanted ovariectomized rats were injected with the AMPK inhibitor compound c (Cc) or vehicle into the caudal fourth ventricle (CV4) prior to micropunch-dissection of individual hypothalamic metabolic loci or assessment of food intake. Cc decreased hindbrain dorsal vagal complex phosphoAMPK (pAMPK) in both E and O; tissue ATP levels were reduced by this treatment in O only. In E/Cc, pAMPK expression was diminished in the lateral hypothalamic area (LHA) and ventromedial (VMH) and paraventricular (PVH) nuclei; only PVH pAMPK was suppressed by this treatment in O/Cc. Cc decreased PVH corticotropin-releasing hormone and arcuate (ARH) proopiomelanocortin (POMC) and neuropeptide Y in O, but suppressed only POMC in E. O/Cc exhibited both augmented (PVH, VMH) and decreased (LHA, ARH) hypothalamic NE content, whereas Cc treatment of E elevated preoptic and dorsomedial hypothalamic nucleus NE. Cc completely or incompletely repressed feeding in E versus O, respectively. Results implicate dorsomedial hindbrain AMPK in physiological stimulus-induced feeding in females. Excepting POMC, hypothalamic neuropeptide responses to this sensor may be contingent on estrogen. Estradiol likely designates hypothalamic targets of altered NE signaling due to hindbrain AMPK activation. Divergent changes in NE content of hypothalamic loci in O/Cc uniquely demonstrate sensor-induced bimodal catecholamine signaling to those sites.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Ingestión de Alimentos , Estradiol/fisiología , Hipotálamo/enzimología , Neuropéptidos/metabolismo , Norepinefrina/metabolismo , Rombencéfalo/enzimología , Adenosina Trifosfato/metabolismo , Animales , Hormona Liberadora de Corticotropina/metabolismo , Ingestión de Alimentos/efectos de los fármacos , Estradiol/administración & dosificación , Femenino , Hipotálamo/efectos de los fármacos , Inyecciones Intraventriculares , Neuropéptido Y/metabolismo , Orexinas/metabolismo , Proopiomelanocortina/metabolismo , Ratas , Ratas Sprague-Dawley , Rombencéfalo/efectos de los fármacos , Factor Esteroidogénico 1/metabolismo
8.
Biol Trace Elem Res ; 106(1): 1-28, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16037607

RESUMEN

Postpartum scalp hair samples from 82 term-pregnancy mother/ neonate pairs were analyzed for their concentrations of zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb), using inductively coupled plasma-mass spectrometry. Maternal and neonatal Zn concentrations had geometric means (and 99% confidence intervals) of 122.5 microg/g (117.9--131.5 microg/g) and 146.9 microg (141.5--156.7 microg/g) respectively. Corresponding Cu values were 18.4 microg/g (17.6--23.8 microg/g) and 6.7 microg/g (6.3--7.6 microg/g). Those of Cd were 0.49 microg/g (0.47--0.69 microg/g) in the mothers and 0.57 microg/g (0.55--0.86 microg/g) in the neonates. For Pb, they were 7.95 microg/g (7.60--9.32 microg/g) and 4.56 microg/g (4.39--5.56 microg/g). Cigarette smoking, despite its relatively low prevalence (19.5%), was associated with lower Zn and higher Cd and Pb concentrations and in lower Zn/Cd and Zn/Pb molar concentration ratios. Smoking also altered interelemental relationships, particularly those of Zn with Cd and Pb and those between Cd and Pb. Smoking frequency appeared to show negative dose-response effects on maternal and neonatal Zn concentrations, Zn/Pb molar concentration ratios, and birth weight. Mothers with a history of oral contraceptive (OC) usage had significantly higher Cu concentrations and lower Zn/Cu molar concentration ratios than non users, with the highest Cu concentrations and lowest Zn/Cu values being associated with third-generation OCs. No similar effects were elicited in the respective neonatal Cu concentrations. Neither alcohol consumption nor prenatal supplementation with iron and/or folic acid had discernible effects on the maternal or neonatal elemental concentrations. The data from this study suggest that in a given population of term-pregnancy mothers and neonates, significant interindividual variations in hair trace element concentrations can occur, irrespective of commonality of general environment, and that lifestyle factors, including cigarette smoking and OC usage history, can be significant contributory factors to such variations. The data are discussed in relation to the effects of smoking-associated exposure to Cd and Pb exposure on Zn availability for placental transfer, as well as on the quantitative maternal Zn supply levels to the fetus resulting from the known tendency of smokers to have lower dietary intakes of Zn.


Asunto(s)
Cadmio/análisis , Cobre/análisis , Cabello/metabolismo , Plomo/análisis , Zinc/análisis , Consumo de Bebidas Alcohólicas , Peso al Nacer , Anticonceptivos Orales , Relación Dosis-Respuesta a Droga , Femenino , Ácido Fólico/metabolismo , Humanos , Recién Nacido , Estilo de Vida , Espectrometría de Masas , Madres , Embarazo , Fumar , Oligoelementos
9.
Neuroscience ; 284: 888-899, 2015 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-25446360

RESUMEN

Dorsal vagal complex (DVC) AMPK regulation of food intake in the estradiol-treated ovariectomized (OVX) female rat is energy state-dependent. Here, RT-PCR array technology was used to identify estradiol-sensitive AMPK-regulated DVC signal transduction pathways that exhibit differential reactivity to sensor activation during energy balance versus imbalance. The AMP mimetic AICAR correspondingly reduced or stimulated cDVC phosphoAMPK (pAMPK) and estrogen receptor-beta (ERß) proteins in full-fed (F) versus 12-h food-deprived (D) estradiol-treated ovariectomized (OVX) rats, but elevated ER-alpha (ERα) in F only. Estradiol suppressed DVC ERß protein and hypoxia, NFκB, STAT3, STAT6, and Hedgehog signaling pathway marker genes against oil-implanted OVX controls. F+(A)ICAR and D+(S)aline groups each exhibited further inhibition of NFκB, STAT3, and Hedgehog pathway genes, and diminished PPAR, Notch, and STAT5 transcripts versus F+S. Conversely, genes in these six pathways were up-regulated by AICAR treatment of D. Results show that in this animal model, acute AMP augmentation or feeding cessation each inhibit both pAMPK and ERß expression, but in combination increase these protein profiles. pAMPK protein and DVC TNF (NFκB), SOCS3 (JAK/STAT), WNT6 (Hedgehog), and FABP1 (PPAR) mRNAs were down- or upregulated in parallel by AICAR in F versus D states, respectively. Further research is needed to determine the impact of ERß on opposing directionality of these responses, and to characterize the role of the aforementioned signaling pathways in hyperphagic responses in the female to AICAR-induced DVC AMPK activation during acute interruption of feeding.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Ingestión de Alimentos/fisiología , Estradiol/metabolismo , Estrógenos/metabolismo , Privación de Alimentos/fisiología , Rombencéfalo/fisiología , Animales , Ingestión de Alimentos/efectos de los fármacos , Estradiol/administración & dosificación , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Estrógenos/farmacología , Femenino , Ovariectomía , Ratas Endogámicas SHR , Ratas Sprague-Dawley , Rombencéfalo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
10.
Neuropharmacology ; 95: 434-47, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25959066

RESUMEN

It has been suggested that amphetamine abuse and withdrawal mimics the diverse nature of bipolar disorder symptomatology in humans. Here, we determined if a single paradigm of amphetamine sensitization would be sufficient to produce both manic- and depressive-related behaviors in mice. CD-1 mice were subcutaneously dosed for 5 days with 1.8 mg/kg d-amphetamine or vehicle. On days 6-31 of withdrawal, amphetamine-sensitized (AS) mice were compared to vehicle-treated (VT) mice on a range of behavioral and biochemical endpoints. AS mice demonstrated reliable mania- and depression-related behaviors from day 7 to day 28 of withdrawal. Relative to VT mice, AS mice exhibited long-lasting mania-like hyperactivity following either an acute 30-min restraint stress or a low-dose 1 mg/kg d-amphetamine challenge, which was attenuated by the mood-stabilizers lithium and quetiapine. In absence of any challenge, AS mice showed anhedonia-like decreases in sucrose preference and depression-like impairments in the off-line consolidation of motor memory, as reflected by the lack of spontaneous improvement across days of training on the rotarod. AS mice also demonstrated a functional impairment in nest building, an ethologically-relevant activity of daily living. Western blot analyses revealed a significant increase in methylation of histone 3 at lysine 9 (H3K9), but not lysine 4 (H3K4), in hippocampus of AS mice relative to VT mice. In situ hybridization for the immediate-early gene activity-regulated cytoskeleton-associated protein (Arc) further revealed heightened activation of corticolimbic structures, decreased functional connectivity between frontal cortex and striatum, and increased functional connectivity between the amygdala and hippocampus of AS mice. The effects of amphetamine sensitization were blunted in C57BL/6J mice relative to CD-1 mice. These results show that a single amphetamine sensitization protocol is sufficient to produce behavioral, functional, and biochemical phenotypes in mice that are relevant to bipolar disorder.


Asunto(s)
Trastorno Bipolar/inducido químicamente , Corteza Cerebral/efectos de los fármacos , Dextroanfetamina/administración & dosificación , Modelos Animales de Enfermedad , Sistema Límbico/efectos de los fármacos , Síndrome de Abstinencia a Sustancias/psicología , Anhedonia , Animales , Trastorno Bipolar/tratamiento farmacológico , Trastorno Bipolar/fisiopatología , Corteza Cerebral/metabolismo , Sistema Límbico/metabolismo , Compuestos de Litio/farmacología , Masculino , Consolidación de la Memoria , Ratones , Ratones Endogámicos C57BL , Actividad Motora , Comportamiento de Nidificación , Vías Nerviosas/efectos de los fármacos , Vías Nerviosas/metabolismo , Psicotrópicos/farmacología , Fumarato de Quetiapina/farmacología , Restricción Física , Especificidad de la Especie , Estrés Psicológico/fisiopatología , Síndrome de Abstinencia a Sustancias/tratamiento farmacológico , Síndrome de Abstinencia a Sustancias/fisiopatología
11.
Neuroscience ; 269: 199-214, 2014 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-24631866

RESUMEN

Neuro-glucostasis is required for normal expression of the steroid positive-feedback-induced preovulatory pituitary luteinizing hormone (LH) surge, a critical element of female reproduction. Glucoprivic signals from the caudal hindbrain restrain this surge, but the cellular source of this stimulus is unclear. Norepinephrine (NE) exerts well-defined stimulatory effects on the reproductive neuroendocrine axis. Our studies show that medullary A2 noradrenergic neurons are both estrogen- and glucoprivic-sensitive. Here, we investigated the premise that the LH surge is inhibited by A2 cell reactivity to hindbrain glucopenia and diminished preoptic NE neurotransmission. Estradiol- and progesterone-primed ovariectomized (OVX) female rats were injected into the caudal fourth ventricle (CV4) with the glucose anti-metabolite, 5-thioglucose (5TG) or saline (SAL) prior to onset of the LH surge. Pretreatment by intra-CV4 delivery of the selective catecholamine neurotoxin, 6-OHDA, attenuated LH output, but prevented inhibition by 5TG. 5TG modified patterns of steroid feedback-associated Fos staining of A2, but not other medullary catecholamine cell groups. Intra-preoptic administration of the alpha1-adrenergic receptor agonist, methoxamine, elicited site-specific reversal of hindbrain glucoprivic suppression of gonadotropin-releasing hormone (GnRH) neuron Fos labeling and LH release. Western blotting of laser-microdissected A2 neurons revealed glucoprivic stimulation of Fos, but inhibition of the catecholamine synthetic enzyme, dopamine-ß-hydroxylase; 5TG also diminished A2 estrogen receptor (ER)-α and progesterone receptor profiles, but augmented ER-ß protein. Intriguingly, A2 AMPK activity was decreased in 5TG-treated rats, despite down-regulation of GLUT3 and no change in MCT2 protein expression. Rostral preoptic GnRH neurons also exhibited decreased AMPK activation simultaneous with apparent reduction of neuropeptide signaling to the pituitary. The present studies demonstrate that hindbrain glucoprivation inhibits the LH surge, in part, by reducing preoptic noradrenergic input, and furthermore implicate A2 neurons as a source of this altered signal. Results also suggest that AMPK sensor deactivation does not supersede the impact of pharmacological inhibition of glucose catabolism on A2 cell function nor afferent signaling of hindbrain glucopenia on GnRH neurons. Further studies are needed to determine if decreased AMPK activation in these cell populations reflect compensatory gain in positive energy balance and/or direct effects of estrogen on AMPK.


Asunto(s)
Neuronas Adrenérgicas/fisiología , Hormona Luteinizante/metabolismo , Receptores de Adenosina A2/metabolismo , Rombencéfalo/fisiología , Proteínas Quinasas Activadas por AMP/metabolismo , Adrenérgicos/farmacología , Neuronas Adrenérgicas/efectos de los fármacos , Agonistas de Receptores Adrenérgicos alfa 1/farmacología , Animales , Biomarcadores/metabolismo , Fármacos del Sistema Nervioso Central/farmacología , Estradiol/farmacología , Femenino , Glucosa/análogos & derivados , Glucosa/farmacología , Hormona Liberadora de Gonadotropina/metabolismo , Hormonas/farmacología , Metoxamina/farmacología , Neuronas/efectos de los fármacos , Neuronas/fisiología , Ovariectomía , Oxidopamina/farmacología , Progesterona/farmacología , Ratas Sprague-Dawley , Rombencéfalo/efectos de los fármacos
12.
Neuroscience ; 278: 20-30, 2014 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-25084049

RESUMEN

Cell-type compartmentation of glucose metabolism in the brain involves trafficking of the oxidizable glycolytic end product, l-lactate, by astrocytes to fuel neuronal mitochondrial aerobic respiration. Lactate availability within the hindbrain medulla is a monitored function that regulates systemic glucostasis as insulin-induced hypoglycemia (IIH) is exacerbated by lactate repletion of that brain region. A2 noradrenergic neurons are a plausible source of lactoprivic input to the neural gluco-regulatory circuit as caudal fourth ventricular (CV4) lactate infusion normalizes IIH-associated activation, e.g. phosphorylation of the high-sensitivity energy sensor, adenosine 5'-monophosphate-activated protein kinase (AMPK), in these cells. Here, we investigated the hypothesis that A2 neurons are unique among medullary catecholamine cells in directly screening lactate-derived energy. Adult male rats were injected with insulin or vehicle following initiation of continuous l-lactate infusion into the CV4. Two hours after injections, A1, C1, A2, and C2 neurons were collected by laser-microdissection for Western blot analysis of AMPKα1/2 and phosphoAMPKα1/2 proteins. Results show that AMPK is expressed in each cell group, but only a subset, e.g. A1, C1, and A2 neurons, exhibit increased sensor activity in response to IIH. Moreover, hindbrain lactate repletion reversed hypoglycemic augmentation of pAMPKα1/2 content in A2 and C1 but not A1 cells, and normalized hypothalamic norepinephrine and epinephrine content in a site-specific manner. The present evidence for discriminative reactivity of AMPK-expressing medullary catecholamine neurons to the screened energy substrate lactate implies that that lactoprivation is selectively signaled to the hypothalamus by A2 noradrenergic and C1 adrenergic cells.


Asunto(s)
Neuronas Adrenérgicas/metabolismo , Epinefrina/metabolismo , Hipoglucemia/metabolismo , Hipotálamo/metabolismo , Lactatos/metabolismo , Bulbo Raquídeo/metabolismo , Norepinefrina/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Neuronas Adrenérgicas/efectos de los fármacos , Animales , Glucemia , Corticosterona/sangre , Epinefrina/análisis , Hipoglucemia/inducido químicamente , Insulina/farmacología , Lactatos/farmacología , Masculino , Bulbo Raquídeo/efectos de los fármacos , Norepinefrina/análisis , Fosforilación , Ratas , Ratas Sprague-Dawley
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