RESUMEN
Purinergic receptors are implicated in nociceptive signaling in small primary afferents via activation of adenosine triphosphate (ATP). ATP appears to mediate HCl-induced transient receptor potential vanilloid receptor 1 (TRPV1) activation in esophageal mucosa. Up-regulation of TRPV1 expression in gastroesophageal reflux disease (GERD) is associated with increased nerve growth factor (NGF) and glial derived neurotrophic factor (GDNF). This study aims to genetically determine the expression of purinergic receptors in severe inflamed human esophagus. Distal esophageal biopsies from the subjects with erosive GERD, asymptomatic patients (AP) and healthy ones were examined. Using real-time qPCR for detecting purinergic receptors (P2X2, P2X3, P2X7, P2Y1, P2Y2, P2Y4, P2Y6 and P2Y12), TRPV1, TRPV4, NGF, and GDNF was done in this study. Both P2X3 and P2X7 mRNA expressions in GERD patients significantly increased than those in healthy controls (P < 0.001) and AP (P < 0.001), but P2X2, P2Y1, P2Y2, P2Y4, P2Y6, P2Y12 or P2Y12 had no difference within the control, AP or GERD subjects. The well correlated expression in P2X3 gene with TRPV1 (r = 0.46, P = 0.002), NGF (r = 0.54, P = 0.0002), and GDNF (r = 0.64, P = 0.0001) was found. The P2X7 gene expressions also well correlated with TRPV1 (r = 0.47, P = 0.002), NGF (r = 0.32, P = 0.037), and GDNF (r = 0.42, P = 0.005). These results suggest that chronic esophagitis increases mRNA expressions of P2X3 and P2X7 receptors accompanied by up-regulation of TRPV1 and neurotrophic factors (NGF and GDNF). These genetical alterations in esophageal mucosa might mediate sensitization of inflamed human esophagus.
Asunto(s)
Esofagitis Péptica/metabolismo , Esófago/metabolismo , Receptores Purinérgicos P2X3/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Canales Catiónicos TRPV/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Expresión Génica , Factor Neurotrófico Derivado de la Línea Celular Glial/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Factor de Crecimiento Nervioso/metabolismo , Receptores Purinérgicos P2X3/genética , Receptores Purinérgicos P2X7/genética , Regulación hacia Arriba , Adulto JovenRESUMEN
BACKGROUND: Transient receptor potential vanilloid-1 (TRPV1) receptor has been implicated in the mechanism of acid induced inflammation in gastro-esophageal reflux disease (GERD). It has been demonstrated that the increase in nerve growth factor (NGF) and glial derived neurotrophic factor (GDNF) was associated with the increased expression of TRPV1. We aimed to determine whether expression of TRPV1 was increased in severe inflamed human esophagus, and to test the hypothesis whether the expression of TRPV1 was mediated by neurotrophic factors such as NGF and GDNF. METHODS: We compared biopsies taken from the distal esophagus of 15 patients with erosive GERD, 16 asymptomatic patients (AP), and 10 healthy controls. We assessed the biopsies with reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative polymerase chain reaction (qPCR) for TRPV1, NGF, and GDNF. Immunohistochemical analysis of TRPV1 protein expression was also determined. KEY RESULTS: Transient receptor potential vanilloid-1 mRNA level and its protein expression were significantly greater in patients with erosive esophagitis than AP (P < 0.001) and healthy controls (P < 0.001). Nerve growth factor and GDNF gene levels in the esophageal mucosa were also significantly increased in patients with erosive esophagitis compared with AP and healthy controls (all P < 0.001). Transient receptor potential vanilloid-1 mRNA correlated well with NGF (r = 0.61, P < 0.001) and GDNF (r = 0.58, P < 0.001). CONCLUSIONS & INFERENCES: These results support the association of NGF and GDNF in the up-regulation of TRPV1 receptors in patients with erosive esophagitis.
Asunto(s)
Esofagitis Péptica/metabolismo , Esófago/metabolismo , Reflujo Gastroesofágico/metabolismo , Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Factor de Crecimiento Nervioso/genética , Canales Catiónicos TRPV/genética , Adulto , Anciano , Esofagitis Péptica/genética , Femenino , Reflujo Gastroesofágico/genética , Expresión Génica , Factor Neurotrófico Derivado de la Línea Celular Glial/metabolismo , Humanos , Inmunohistoquímica , Inflamación/genética , Inflamación/metabolismo , Masculino , Persona de Mediana Edad , Factor de Crecimiento Nervioso/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Canales Catiónicos TRPV/metabolismo , Regulación hacia ArribaRESUMEN
OBJECTIVES: Physiological and behavioral circadian rhythmicities are exhibited by all mammals and are generated by intracellular levels of circadian oscillators, which are composed of transcriptional/translational feedback loops involving a set of circadian-clock genes, such as Clock, Per1-3, Cry1-2, Bmal1, Dbp, E4BP4 and CK1varepsilon. These circadian-clock genes play important roles in regulating circadian rhythms and also energy homeostasis and metabolism. Determining whether obesity induced by high-fat diet affected the expressions of circadian-clock genes and their related genes in peripheral tissues, was the main focus of this study. To address this issue, we fed male C57BL/6 mice a high-fat diet for 11 months to induce obesity, hyperglycemic, hypercholesterolemic and hyperinsulinemic symptoms, and used quantitative real-time reverse transcription-PCR to measure gene expression levels. RESULTS: We found that the expressions of circadian-clock genes and circadian clock-controlled genes, including Per1-3, Cry1-2, Bmal1, Dbp, E4BP4, CK1varepsilon, PEPCK, PDK4 and NHE3, were altered in the livers and/or kidneys. CONCLUSIONS: These results indicate that obesity induced by high-fat diet alters the circadian-clock system, and obesity and metabolic syndrome are highly correlated with the expressions of circadian-clock genes and their downstream, circadian clock-controlled genes.
Asunto(s)
Peso Corporal/genética , Péptidos y Proteínas de Señalización del Ritmo Circadiano/genética , Ritmo Circadiano/genética , Síndrome Metabólico/genética , Obesidad/genética , Animales , Proteínas CLOCK/genética , Proteínas CLOCK/metabolismo , Péptidos y Proteínas de Señalización del Ritmo Circadiano/metabolismo , Grasas de la Dieta/administración & dosificación , Regulación de la Expresión Génica , Riñón/metabolismo , Hígado/metabolismo , Masculino , Síndrome Metabólico/metabolismo , Ratones , Ratones Endogámicos C57BL , Obesidad/metabolismo , Transactivadores/genéticaRESUMEN
Depression and/or anxiety are major comorbidities of epilepsy. However, the contribution of absence epileptic discharges in psychiatric syndromes is inconclusive. This study aimed to clarify the influence of absence seizure in anxiety- and depression-like behaviors using normal Wistar rats and Long-Evans rats with spontaneous spike-wave discharges (SWDs). Anxiety-like behaviors were evaluated by the open field (OF) and elevated plus maze (EPM) tests, and depression-like behaviors by the forced swimming (FS) and sucrose consumption (SC) tests. Long-Evans rats displayed significantly higher frequency and longer duration in the open arms of the EPM and in the center zone of the OF than did Wistar rats. Normalized behavioral indexes by movement also were significantly higher in Long-Evans rats. An excess of SWD numbers was associated with lower indexes and worse movement in the two behavioral tests. Ethosuximide eliminated the seizure frequency-dependent relationship and also significantly increased all indexes of the EPM test. Additionally, Long-Evans rats revealed significantly longer immobility in the FS test and lower consumption of sucrose solution in the SC test than did Wistar rats. Meanwhile, no relationship was found between immobility of the FS test and SWD number. Ethosuximide ameliorated depression-like behavior of Long-Evans rats that was equal to that of Wistar rats. Thus, Long-Evans rats showed seizure frequency-related exacerbation in anxiety-like behavior; and they displayed a depressive propensity. Our data suggest that generalized SWDs may have distinct influences in anxious and depressive behaviors.
Asunto(s)
Potenciales de Acción/fisiología , Ansiedad/fisiopatología , Depresión/fisiopatología , Epilepsia Tipo Ausencia/fisiopatología , Conducta Exploratoria/fisiología , Potenciales de Acción/efectos de los fármacos , Animales , Anticonvulsivantes/farmacología , Ansiedad/complicaciones , Depresión/complicaciones , Modelos Animales de Enfermedad , Epilepsia Tipo Ausencia/complicaciones , Epilepsia Tipo Ausencia/tratamiento farmacológico , Reacción de Fuga/fisiología , Etosuximida/farmacología , Pérdida de Tono Postural/fisiología , Masculino , Ratas , Ratas Long-Evans , Ratas WistarRESUMEN
The present studies aimed to determine whether estradiol (E(2)) modulates the stimulation of cocaine- and amphetamine-regulated transcript (CART) peptide in the mesolimbic and nigrostriatal dopaminergic systems. I.c.v. administration of the CART peptide (55-102, 1 microg/3 microl) increased dopamine turnover (3,4-dihydroxyphenylacetic acid, DOPAC) in the nucleus accumbens (NA) and striatum (ST) in ovariectomized (OVX) female Sprague-Dawley rats with E(2)-priming. This stimulation of NA and ST DOPAC contents by CART peptide was found in OVX+E(2) female rats, but not in OVX only female rats, suggesting E(2) is an important factor in modulating the stimulatory effect of CART in the regulation of NA and ST DOPAC contents. This stimulation by CART peptide was also restored by treatment with the water-soluble form of E(2), but not by treatment with the membrane-impermeable form of E(2) in OVX female rats, suggesting that E(2) acts through intracellular rather than extracellular mechanisms to modulate the effects of CART peptide. Furthermore, the effects of water-soluble form of E(2) were blocked by E(2) antagonist, tamoxifen, but not by testosterone antagonist, flutamide. Our findings are the first to demonstrate that that E(2) plays a regulatory role in stimulation of CART peptide in mesolimbic and nigrostriatal dopaminergic systems in female rats, and E(2) acts through its own receptor(s) and intracellular mechanisms.
Asunto(s)
Encéfalo/metabolismo , Dopamina/metabolismo , Estradiol/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Femenino , Ovariectomía , Ratas , Ratas Sprague-DawleyRESUMEN
To probe the potential role of Th1 versus Th2 reactivity underlying the hygiene hypothesis, intrinsic levels of Th1-associated and Th2-associated antibodies in the serum of wild rodents were compared with that in various strains of laboratory rodents. Studies using rat lung antigens as a target indicated that wild rats have substantially greater levels of autoreactive, polyreactive immunoglobulin G (IgG), but not autoreactive, polyreactive IgM than do laboratory rats, both on a quantitative and qualitative basis. Increased levels of serum IgG and IgE were observed in both wild rats and wild mice relative to their laboratory-raised counterparts, with the effect being most pronounced for IgE levels. Further, wild rats had greater intrinsic levels of both Th1- and Th2-associated IgG subclasses than did lab rats. The habitat (wild versus laboratory raised) had a more substantial impact on immunoglobulin concentration than did age, strain or gender in the animals studied. The presence in wild rodents of increased intrinsic, presumably protective, non-pathogenic responses similar to both autoimmune (autoreactive IgG, Th1-associated) and allergic (IgE, Th2-associated) reactions as well as increased levels of Th1-associated and Th2-associated IgG subclasses points toward a generally increased stimulation of the immune system in these animals rather than a shift in the nature of the immunoreactivity. It is concluded that, at least to the extent that feedback inhibition is a controlling element of immunoreactivity, an overly hygienic environment may affect the threshold of both types of immune responses more so than the balance between the different responses.
Asunto(s)
Animales de Laboratorio/inmunología , Animales Salvajes/inmunología , Higiene , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Roedores/inmunología , Animales , Formación de Anticuerpos/inmunología , Autoinmunidad/inmunología , Ambiente , Ensayo de Inmunoadsorción Enzimática , Femenino , Hipersensibilidad/inmunología , Masculino , Ratones , Ratones Endogámicos , Ratas , Roedores/sangre , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
The present studies aimed to determine whether cocaine- and amphetamine-regulated transcript (CART) peptide in the nucleus of accumbens shell (AcbSh) is implicated in the regulation of food intake. Bilateral intranuclear injections of CART peptide (55-102, 1 microg/microl/side) into the AcbSh decreased food intake with no change in locomotion activity and attenuated the orexigenic effect of the GABA(A) agonist muscimol (100 ng/microl/side) in male Sprague-Dawley rats. Decreased food intake after bilateral intranuclear injections of CART was more sustained in freely fed rats than in food-deprived rats, suggesting fuel availability is an important factor in modulating the function of CART in the regulation of feeding. Our anatomical findings indicate that in addition to the perifornical region and the arcuate nucleus, some neurons within the AcbSh also project within the AcbSh. Moreover, many of these efferent cells contain CART immunoreactivity, including those which reside within the AcbSh, suggesting that accumbal CART circuitry is involved in the central function of the nucleus accumbens. Furthermore, fasting suppressed CART mRNA levels in the AcbSh, paraventricular nucleus of the hypothalamus, arcuate nucleus, and the perifornical region, indicating that the Acb is sensitive to fuel availability to an extent similar to those regions in the hypothalamus. Our findings are the first to demonstrate that CART mRNA in the AcbSh is sensitive to metabolic challenges and that injection of CART peptide into the AcbSh has an inhibitory effect on food intake.
Asunto(s)
Conducta Alimentaria/efectos de los fármacos , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/farmacología , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/fisiología , Animales , Ayuno/fisiología , Conducta Alimentaria/fisiología , Agonistas del GABA/farmacología , Agonistas de Receptores de GABA-A , Expresión Génica/fisiología , Masculino , Microinyecciones , Actividad Motora/efectos de los fármacos , Muscimol/farmacología , ARN Mensajero/análisis , Ratas , Ratas Sprague-DawleyRESUMEN
The effects of the cocaine- and amphetamine-regulated transcript (CART) peptide on central dopaminergic (DA) neurons were examined in ovariectomized, estrogen-primed Sprague-Dawley rats in both the morning and afternoon. Intracerebroventricular administration of 1 microg, but not lower doses of the CART peptide (55-102), either in the morning or afternoon produced a prolonged increase in the 3,4-dihydroxyphenylacetic acid (DOPAC) level in the median eminence (ME) and a corresponding decrease of serum prolactin (PRL) levels, which resulted from stimulation of tuberoinfundibular dopaminergic neurons. The CART peptide stimulated DOPAC levels in the striatum (ST), nucleus accumbens (NA), hypothalamic paraventricular nucleus (PVN), and periventricular (A14), but had no effect in the medial prefrontal cortex (MPFC) or suprachiasmatic nucleus (SCN). These effects of the CART peptide on stimulation of central DA systems and inhibition of PRL levels are specific because the inactive form of the CART peptide (0.1 and 1 microg) could not induce a similar response. Stimulatory effects of the CART peptide on different central DA systems displayed differential time-response profiles in the NA and ST, ME, and PVN and A14. These findings indicate that the CART peptide may selectively regulate certain central DA neuronal activities.
Asunto(s)
Química Encefálica/efectos de los fármacos , Dopamina/fisiología , Proteínas del Tejido Nervioso/farmacología , Neuronas/efectos de los fármacos , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Electroquímica , Femenino , Inyecciones Intraventriculares , Neuronas/metabolismo , Ovariectomía , Fragmentos de Péptidos/farmacología , Prolactina/sangre , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
High densities of mRNAs for three rhythm-related genes, rPeriod1 (rPer1), rPer2, and rClock, which share high homology in Drosophila and mice, were found in the hypothalamic suprachiasmatic nucleus (SCN). The SCN, however, is not the only brain region that expresses these genes. To understand the distributions and possible physiological roles of these rhythm-related genes, we examined the gene expressions of rPer1, rPer2, and rClock in different brain regions by serial coronal, sagittal, and horizontal brain sections in Sprague-Dawley male rats. Animals were housed in a light-controlled room (lights on from 0600 to 1800 h) and killed at 1000 or 1200 h, which corresponds to Zeitgeber time 4 or 6. Semi-quantitative in situ hybridization with (35)S-riboprobes was used to evaluate mRNA levels. The mRNAs of rPer1, rPer2, and rClock were widely distributed in the rat CNS, including the olfactory bulb, cortex, piriform cortex, SCN, ventromedial hypothalamus, arcuate nucleus, hippocampus, mammillary nucleus, pontine nucleus, superior and inferior colliculus, cerebellum, median eminence/pars tuberalis, pineal gland, and pituitary. The expression patterns of mRNAs for rPer1 and rPer2 were almost identical. In contrast, different expression patterns were observed between rClock and rPer1 or rPer2 in several brain regions, including the hypothalamic supraoptic and suprachiasmatic nuclei, the paraventricular zone of the caudate putamen, the superior olivary nucleus, and anterior and intermediate lobes of the pituitary. These findings suggest that the different expression patterns observed for rPer1, rPer2, and rClock might be due to their different physiological role(s) in those brain regions.
Asunto(s)
Encéfalo/metabolismo , Ritmo Circadiano/genética , Regulación de la Expresión Génica/genética , Neuronas/metabolismo , Proteínas Nucleares/genética , Transactivadores/genética , Animales , Encéfalo/citología , Proteínas CLOCK , Proteínas de Ciclo Celular , Masculino , Neuronas/citología , Proteínas Circadianas Period , Glándula Pineal/citología , Glándula Pineal/metabolismo , Hipófisis/citología , Hipófisis/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Factores de TranscripciónRESUMEN
Effects of orphanin FQ (OFQ) on central dopaminergic (DA) neurons and serum prolactin (PRL) were examined in ovariectomized, estrogen-primed Sprague-Dawley rats. The activities of central DA neurons, including the tuberoinfundibular (TI), nigrostriatal, mesolimbic, and incertohypothalamic ones, were determined by measuring the levels of 3,4-dihydroxyphenylacetic acid (DOPAC), the major metabolite of dopamine, in their projection regions in the brain by HPLC plus electrochemical detection. Intracerebroventricular administration of OFQ lowered DOPAC levels in the median eminence (ME), striatum, nucleus accumbens, and hypothalamic paraventricular nucleus in a dose (0.01-10 microg)- and time (30-90 min)-dependent manner. In contrast, OFQ increased DOPAC in the suprachiasmatic nucleus and had no effect in the periventricular nucleus. Serum PRL levels exhibited a typical inverse relationship with the activity of TIDA neurons, as determined by DOPAC levels in the ME. In the afternoon, we observed an endogenous decrease of ME DOPAC level accompanied by a PRL surge in estrogen-primed female rats. Although OFQ caused further decrease of ME DOPAC in the afternoon, it failed to augment the PRL surge level. Although pretreatment of an antisense oligodeoxynucleotide against the opioid receptor-like receptor gene had no effect on basal ME DOPAC levels in the morning or afternoon, it attenuated the afternoon PRL surge. Furthermore, it blocked the effects of exogenous OFQ on ME DOPAC and serum PRL levels, whereas the sense or missense oligodeoxynucleotide had no effect. These results indicate that OFQ and its receptors may be involved in the regulation of central DA neuronal activity and PRL secretion.
Asunto(s)
Encéfalo/efectos de los fármacos , Dopamina/fisiología , Neuronas/efectos de los fármacos , Péptidos Opioides/farmacología , Prolactina/metabolismo , Ácido 3,4-Dihidroxifenilacético/análisis , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Núcleo Arqueado del Hipotálamo/química , Encéfalo/fisiología , Ritmo Circadiano , Cuerpo Estriado/química , Relación Dosis-Respuesta a Droga , Estradiol/administración & dosificación , Femenino , Inyecciones Intraventriculares , Eminencia Media/química , Neuronas/fisiología , Núcleo Accumbens/química , Péptidos Opioides/administración & dosificación , Ovariectomía , Núcleo Hipotalámico Paraventricular/química , Prolactina/sangre , Ratas , Ratas Sprague-Dawley , NociceptinaRESUMEN
OVCAR-5 is a human epithelial carcinoma cell line of the ovary, established from the ascitic fluid of a patient with progressive ovarian adenocarcinoma without prior cytotoxic treatment. The unique growth pattern of ovarian carcinoma makes it an ideal model for examining the anticancer activity of contortrostatin (CN), a homodimeric disintegrin from southern copperhead venom. FACS analysis revealed that OVCAR-5 is integrin alphavbeta3 negative, but alphavbeta5 positive. CN effectively blocks the adhesion of OVCAR-5 cells to several extracellular matrix proteins and inhibits tumor cell invasion through an artificial basement membrane. In a xenograft nude mouse model with intraperitoneal introduction of OVCAR-5 cells, intraperitoneal injection of CN was used for therapy. Tumor dissemination in CN-treated versus control groups was studied by gross examination, and antiangiogenic potential was examined by factor VIII immunohistochemistry and image analysis. CN not only significantly inhibited ovarian cancer dissemination in the nude mouse model, but it also dramatically prevented the recruitment of blood vessels to tumors at secondary sites.
Asunto(s)
Desintegrinas/farmacología , Neovascularización Patológica/prevención & control , Neoplasias Ováricas/patología , Venenos de Serpiente/química , Agkistrodon , Animales , Adhesión Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Desintegrinas/administración & dosificación , Proteínas de la Matriz Extracelular/metabolismo , Femenino , Humanos , Ratones , Ratones Desnudos , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Neovascularización Patológica/tratamiento farmacológico , Neoplasias Ováricas/tratamiento farmacológico , Trasplante Heterólogo , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/trasplanteRESUMEN
Whether the tuberoinfundibular dopaminergic (TIDA) neurons resided in the dorsomedial arcuate nucleus (dmARN) can respond to dopamine and a dopamine D(3) receptor agonist, 7-hydroxydipropylaminotetralin (7-OH-DPAT), was the focus of this study. In studies using extracellular single-unit recording of dmARN neurons in brain slices obtained from ovariectomized rats, dopamine and 7-OH-DPAT inhibited 60.1% (n = 141) and 80.9% (n = 47) of recorded dmARN neurons, respectively. Other dopamine D(1) or D(2) receptor agonists were not as effective. Intracerebroventricular injection of 7-OH-DPAT (10(-9) mol/3 microl) in ovariectomized, estrogen-primed rats significantly lowered the TIDA neuronal activity as determined by 3, 4-dihydroxyphenylacetic acid (DOPAC) levels in the median eminence. Co-administration of a putative D(3) receptor antagonist, U-99194A, could prevent the effect of 7-OH-DPAT. Unilateral microinjection of 7-OH-DPAT or dopamine itself (10(-11)-10(-9) mol/0.2 microl) into the right dmARN exhibited the same inhibitory effect on TIDA neurons. In all, dopamine may act on D(3) receptors to exhibit an inhibitory effect on its own release from the TIDA neurons.
Asunto(s)
Núcleo Arqueado del Hipotálamo/efectos de los fármacos , Agonistas de Dopamina/farmacología , Dopamina/metabolismo , Dopamina/farmacología , Neuronas/efectos de los fármacos , Receptores de Dopamina D2/efectos de los fármacos , Tetrahidronaftalenos/farmacología , Animales , Núcleo Arqueado del Hipotálamo/citología , Núcleo Arqueado del Hipotálamo/metabolismo , Femenino , Sistema Hipotálamo-Hipofisario/citología , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Sistema Hipotálamo-Hipofisario/metabolismo , Neuronas/citología , Neuronas/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D3 , Tuber Cinereum/citología , Tuber Cinereum/efectos de los fármacos , Tuber Cinereum/metabolismoRESUMEN
The aims of the present study were to determine if melatonin exerts an effect on prolactin (PRL) secretion via the tuberoinfundibular dopaminergic (TIDA) neurons and if endogenous or exogenous melatonin has an entraining effect on the rhythmic changes of TIDA neuronal activity and PRL secretion. Melatonin given in the morning (10:00 h), dose- (0.01-1 mg/kg, ip) and time- (at 15 and 60 min, but not at 30 min) dependently stimulated TIDA neuronal activity in ovariectomized (OVX), estrogen-treated rats as determined by 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the median eminence (ME). Serum PRL was concurrently inhibited by the injection. Melatonin administered in the afternoon (15:00 h) was even more effective in stimulating the lowered TIDA neuronal activity and inhibiting the increased PRL level than that given in the morning (10:00 h). S-20098, a melatonin agonist was also effective in stimulating the TIDA neurons. In contrast, S-20928, a putative melatonin antagonist, while it had no effect by itself, blocked the effect of S-20098. Although S-20928 failed to prevent melatonin's effect on ME DOPAC levels, six interspaced injections of S-20928, from 18:00 to 01:30 h, significantly blocked the increase of ME DOPAC levels at 03:00 h, indicating that the endogenous melatonin may play a role. We further used rats that received daily injection of melatonin (1 mg/kg, ip) at 18:00 h for 10 days and found that the injection augmented basal TIDA neuronal activity at 11:00 h and blunted the afternoon PRL surge. In all, melatonin can have an inhibitory effect on PRL secretion by stimulating the TIDA neurons, and it may help to entrain the circadian rhythms of both TIDA neuronal activity and PRL secretion.
Asunto(s)
Ritmo Circadiano/efectos de los fármacos , Hipotálamo Medio/fisiología , Melatonina/farmacología , Neuronas/fisiología , Prolactina/antagonistas & inhibidores , Ácido 3,4-Dihidroxifenilacético/metabolismo , Acetamidas/farmacología , Animales , Ritmo Circadiano/fisiología , Relación Dosis-Respuesta a Droga , Femenino , Hipotálamo Medio/efectos de los fármacos , Melatonina/agonistas , Melatonina/antagonistas & inhibidores , Naftalenos/farmacología , Neuronas/efectos de los fármacos , Ovariectomía , Prolactina/sangre , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
Cysteamine, a potent depletor of prolactin and somatostatin, was used to determine the role of prolactin and somatostatin in the control of central dopamine neurones in prepubertal rats. Cysteamine (100 mg/kg, i.p., twice daily) was injected for 7, 14 or 21 days in 28-day-old Sprague-Dawley female rats in one study and for 3 days in 35-day-old rats in another. In control rats, the 3, 4-dihydroxyphenylacetic acid (DOPAC) levels in the median eminence increased threefold from day 35 to day 49, and serum prolactin concentration increased about 50%. Cysteamine lowered serum prolactin concentrations to 20%, and median eminence DOPAC and dopamine levels to 32-50% of control levels in both studies. The DOPAC levels in the nucleus accumbens and striatum were also lowered, while both DOPAC and dopamine in the paraventricular nucleus and periventricular nucleus (A14) were increased by cysteamine. A single injection of rat prolactin (0.01, 0.1 or 1 mg/kg) significantly increased DOPAC or DOPA levels in the median eminence, nucleus accumbens and striatum, but not in the paraventricular nucleus or A14 at 14 h later in 28-day old female rats or in 40-day-old rats pretreated with cysteamine. In contrast, central injection of somatostatin dose (0.001-1 microg/rat) and time (30-90 min) dependently decreased the DOPAC levels in the median eminence, paraventricular nucleus and A14 and increased those in the nucleus accumbens and striatum of adult female rats. These results indicate that serum prolactin is important for the maturation and maintenance of dopamine systems in the median eminence, nucleus accumbens and striatum, while somatostatin exhibits inhibitory and stimulatory effects on hypothalamic and midbrain dopamine systems, respectively.
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Cisteamina/farmacología , Hormonas/farmacología , Neuronas/efectos de los fármacos , Prolactina/fisiología , Protectores contra Radiación/farmacología , Maduración Sexual/fisiología , Somatostatina/farmacología , Ácido 3,4-Dihidroxifenilacético/análisis , Factores de Edad , Animales , Química Encefálica/efectos de los fármacos , Cuerpo Estriado/química , Cuerpo Estriado/citología , Dopamina/fisiología , Estrógenos/farmacología , Femenino , Hipotálamo/química , Hipotálamo/citología , Eminencia Media/química , Eminencia Media/citología , Neuronas/citología , Núcleo Accumbens/química , Núcleo Accumbens/citología , Ovariectomía , Núcleo Hipotalámico Paraventricular/química , Núcleo Hipotalámico Paraventricular/citología , Hipófisis/química , Hipófisis/citología , Ratas , Ratas Sprague-Dawley , Estimulación QuímicaRESUMEN
The Mahogany/Attractin gene (Atrn) has been proposed as a downstream mediator of Agouti signaling because yellow hair color and obesity in lethal yellow (A(y)) mice are suppressed by the mahogany (Atrn(mg)) mutation. The present study examined the distribution of Atrn mRNA in the brain and spinal cord by in situ hybridization. Atrn mRNA was found widely distributed throughout the central nervous system, with high levels in regions of the olfactory system, some limbic structures, regions of the brainstem, cerebellum and spinal cord. In the hypothalamus, Atrn mRNA was found in specific nuclei including the suprachiasmatic nucleus, the supraoptic nucleus, the medial preoptic nucleus, the paraventricular hypothalamic nucleus, the ventromedial hypothalamic nucleus, and the arcuate nucleus. These results suggest a broad spectrum of physiological functions for the Atrn gene product.
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Sistema Nervioso Central/metabolismo , Glicoproteínas/metabolismo , Proteínas de la Membrana/metabolismo , Animales , Glicoproteínas/genética , Homeostasis , Hibridación in Situ , Técnicas In Vitro , Masculino , Proteínas de la Membrana/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
Benzophenone is an ultraviolet (UV)-absorbing agent that has been used in industry and medicine for more than 30 years. Consumers of cosmetics and sunscreens containing UV-absorbers are exposed to benzophenones on a daily basis, owing to the widespread use of these compounds. However, the efficacy of these compounds as scavengers of oxidative stress is still not well established. In the present study, we investigate the antioxidative capacity of six sunscreen benzophenone compounds. A primary myoblast culture was mixed in vitro with 100 microM menadione. The cytotoxic effect by menadione-induced oxidative stress was monitored by the lucigenin- or luminol-amplified chemiluminescence, methylthiotetrazole (MTT) assay, and the antioxidative effects of various benzophenone compounds were evaluated. The results showed that the addition of menadione can induce oxidative stress on myoblasts by superoxide and hydrogen peroxide production, which can be eradicated by superoxide dismutase (SOD) and catalase, respectively, in a dose-dependent mode. The catalase has a protective effect on the cytotoxicity induced by menadione as measured by the MTT assay, while the SOD does not. The selected benzophenones also have a significant scavenging effect on the menadione-induced cell death on the myoblasts. The ortho-dihydroxyl structure and other hydroxy groups in the same ring have a stronger scavenging effect on the superoxide anion on myoblasts; thus, a stable penoxy radical may be formed. The mechanism of this effect remains to be clarified.
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Benzofenonas/farmacología , Depuradores de Radicales Libres/farmacología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Acridinas , Animales , Supervivencia Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Humanos , Técnicas In Vitro , Mediciones Luminiscentes , Luminol , Músculo Esquelético/citología , Estrés Oxidativo/efectos de los fármacos , Ratas , Protectores Solares/farmacología , Superóxido Dismutasa/farmacología , Sales de Tetrazolio , Tiazoles , Vitamina K/toxicidadRESUMEN
This study analyzed the quantitative relationship between keytapping times and ergonomic principles in typewriting skills. Keytapping times and key-operating characteristics of a female subject typing on the Qwerty and Dvorak keyboards for six weeks each were collected and analyzed. The results showed that characteristics of the typed material and the movements of hands and fingers were significantly related to keytapping times. The most significant factors affecting keytapping times were association frequency between letters, consecutive use of the same hand or finger, and the finger used. A regression equation for relating keytapping times to ergonomic principles was fitted to the data. Finally, a protocol for design of computerized keyboard layout based on the regression equation was proposed.
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Terminales de Computador , Ergonomía/instrumentación , Escritura , Adulto , Diseño de Equipo , Femenino , Dedos/fisiología , Lateralidad Funcional/fisiología , Mano/fisiología , Humanos , Modelos Estadísticos , Destreza Motora/fisiología , Análisis de RegresiónRESUMEN
BACKGROUND: Acute lower respiratory illness (LRI) early in life has been implicated as a factor for adverse respiratory outcomes later in life. Factors that predispose infants to LRI with wheezing have not been conclusively defined. OBJECTIVES: This prospective study assessed factors that might contribute to LRI with wheezing in the first 2 years of life. METHODS: Seventy-one healthy full-term infants (44 boys, 27 girls) completed the 2-year follow-up. Demographic and environmental factors were evaluated by questionnaire. Respiratory function was assessed by single occlusion technique and rapid thoracic compression technique. Both techniques were performed successfully in 40 infants at 2.6 (+/- 1.4) months old before they developed any episode of LRI. RESULTS: Eighteen infants (25%) developed LRI with wheezing. The first episode of LRI with wheezing occurred in the first year of life in 8 infants, and in the second year of life in 10 infants. There were no significant differences in the demographic or environmental features between infants with or without wheezing LRI, or between infants who acquired LRI with wheezing in the second year of life and those who did not acquire or acquired in the first year of life. Infants from different groups did not differ in airway resistance or maximal flow at functional residual capacity. Infants who developed LRI with wheezing had higher incidence of low values for total respiratory system compliance corrected for body weight compared with those who did not (5/30 versus 6/10, odds ratio = 7.5, 95% confidence interval: 1.53 to 36.7, P = .013). None of the variables of the pulmonary function test could differentiate infants who subsequently developed LRI with wheezing in the first year of life or did not develop any episode of LRI with wheezing from those who developed LRI with wheezing in the second year of life. CONCLUSIONS: Differences in lung function in early life may predispose infants to LRI with wheezing in the first 2 years of life.
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Ruidos Respiratorios/etiología , Infecciones del Sistema Respiratorio/epidemiología , Enfermedad Aguda , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Hipersensibilidad Inmediata/epidemiología , Hipersensibilidad Inmediata/genética , Lactante , Pulmón/fisiopatología , Mediciones del Volumen Pulmonar , Masculino , Neumonía/complicaciones , Neumonía/epidemiología , Estudios Prospectivos , Distribución Aleatoria , Pruebas de Función Respiratoria , Infecciones del Sistema Respiratorio/complicaciones , Factores de Riesgo , Factores Sexuales , Taiwán/epidemiología , Contaminación por Humo de Tabaco/estadística & datos numéricos , Aumento de PesoRESUMEN
This report concerns a 10-month-old boy, admitted to the Veterans General Hospital-Kaohsiung with generalized tonic convulsion and aspiration pneumonia. He was found to have had developmental regression, progressive hypotonia and hepatosplenomegaly since four months of age. Physical examination revealed a large head circumference (97th percentile), frontal bossing, depressed nasal bridge, hepatosplenomegaly, broad hands and short fingers. Neurologic examination showed poor control of eye movement, profound hypotonia, muscle weakness, brisk deep tendon reflexes and Babinski's sign. Hypoplasia of the vertebral bodies with anterior beaking, wedge-shaped metacarpals, spatulated ribs and a J-shaped sella turcica were displayed on bone radiographs. Cranial computerized tomography scans showed diffuse brain atrophy, dilated ventricles and calcification of the bilateral basal ganglia. Vacuolated lymphocytes were noted in a peripheral blood smear. Type 1 GM1 gangliosidosis was diagnosed based on a deficiency of beta-galactosidase activity. To our knowledge, basal ganglia calcification in type 1 GM1 gangliosidosis has never been reported in the literature. We suggest that type 1 GM1 gangliosidosis be considered in the differential diagnosis of patients with an early onset of neurologic decline, organomegaly and basal ganglia calcification.
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Enfermedades de los Ganglios Basales/etiología , Calcinosis/etiología , Gangliosidosis GM1/diagnóstico , Gangliosidosis GM1/complicaciones , Humanos , Lactante , MasculinoRESUMEN
Contortrostatin, a 13.5 kDa disulfide-linked homodimeric polypeptide possessing an Arg-Gly-Asp sequence, was isolated from venom of the southern copperhead snake. Daily injection of contortrostatin into the primary tumor of human breast cancer MDA-MB-435 carried in nude mice significantly inhibited tumor growth and neovascularization of the tumor tissue. On the chick embryo chorioallantoic membrane, contortrostatin inhibited angiogenesis induced by MDA-MB-435 cells, basic fibroblast growth factor, and vascular endothelial growth factor. In addition, contortrostatin effectively blocked adhesion of human umbilical vein endothelial cells (HUVEC) to immobilized vitronectin and significantly inhibited invasion of HUVEC through a Matrigel barrier. Competitive binding assays and adhesion assays with different integrin antibodies suggested that integrin alpha(v)beta3 is a binding site for contortrostatin on vascular endothelial cells. Detachment of HUVEC from vitronectin by contortrostatin induced apoptosis. HUVEC adhered and spread well on immobilized contortrostatin without undergoing apoptosis, suggesting that it is the inhibition of adhesion and spreading of HUVEC on extracellular matrix proteins, rather than binding of contortrostatin to integrins per se, that triggers apoptosis. We conclude that contortrostatin binds to alpha(v)beta3, and interferes with the anchorage-dependent survival mechanism of the vascular endothelial cells, and the mobility of the cells. The consequent suppression of angiogenesis is an important component of the antineoplastic activity of contortrostatin.