RESUMEN
The endocrine disruptor di-(2-ethylhexyl) phthalate (DEHP) is used in a variety of consumer products made with polyvinyl chloride and also in the manufacture of medical devices. DEHP disrupts reproductive tract development in an antiandrogenic manner and also may induce neurobehavioral changes. The aim of this study was to investigate the effects of chronic postnatal exposure to DEHP (30 mg/kg body weight/day, orally from birth to day 60) on the neuroendocrine regulation of the gonadal axis and its impact on the anxiety-like behavior in adult male rats, as well as the probable participation of the GABAergic system in these effects. DEHP produced a significant increase in plasmatic luteinizing hormone and follicle stimulating hormone, as well as significant testosterone decrease, accompanied with a decrease in hypothalamic gamma-aminobutyric acid (GABA) concentration. On the other hand, DEHP increased the anxiety-like behavior in the elevated plus maze test, evidenced by a significant decrease in the percentages of time spent in the open arms and the frequency in the open arm entries and a significant increase in the percentage of time spent in closed arms. Neuroendocrine and behavioral effects were reversed by GABA agonists, muscimol (2 mg/kg i.p. ) and baclofen (10 mg/kg i.p.). In conclusion, chronic DEHP postnatal exposure induced a disruption in the neuroendocrine regulation of the testicular axis in young adult male rats, and this effect was correlated with an anxiety-like behavior. Since GABA agonists reversed these effects, the results suggest that GABA could participate in the modulation of reproductive and behavioral DEHP effects.
Asunto(s)
Ansiedad/metabolismo , Dietilhexil Ftalato/toxicidad , Disruptores Endocrinos/toxicidad , Ácido gamma-Aminobutírico/metabolismo , Animales , Animales Recién Nacidos , Ansiedad/inducido químicamente , Conducta Animal/efectos de los fármacos , Femenino , Hormona Folículo Estimulante/sangre , Agonistas de Receptores de GABA-A/farmacología , Agonistas de Receptores GABA-B/farmacología , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Hormona Luteinizante/sangre , Masculino , Ratas Wistar , Reproducción/efectos de los fármacos , Testosterona/sangreRESUMEN
The research work studies the effect of providing a low dose of bisphenol A (BPA), on the reproductive axis of prepubertal female rats. Wistar mated rats were treated with either 0.1% ethanol or BPA in their drinking water until their offspring were weaned on the 21 day of birth. The estimated average dose of exposure to dams was approximately 3µg/kg/day. The pups were sacrificed at the 30th day of life. Body weight at the moment of the sacrifice was significantly higher in the group exposed to BPA; ovarian weight and its relative weight were not modified. LH and estradiol levels increased significantly, meanwhile FSH ones showed no significant changes. The number of primary, secondary and atretic follicles increased and antral ones was decreased. Our results demonstrated that early exposure to a low dose of BPA disrupts the normal function of the reproductive axis in prepubertal female rats.
Asunto(s)
Compuestos de Bencidrilo/toxicidad , Disruptores Endocrinos/toxicidad , Folículo Ovárico/efectos de los fármacos , Fenoles/toxicidad , Animales , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Folículo Ovárico/patología , Hipófisis/efectos de los fármacos , Embarazo , Efectos Tardíos de la Exposición Prenatal , Ratas Wistar , Maduración SexualRESUMEN
Di-2-ethylhexyl phthalate (DEHP) is the most widely used phthalate to convey flexibility and transparency to plastic products made of polyvinyl chloride. It has been recognized as endocrine disruptor and associated with reproductive toxic effects. We examined the effects of perinatal exposure to DEHP on anxiety-like behavior, using the Elevated Plus Maze (EPM) test, in male and female rats at different stages of sexual development. Anxiety-like behavior was expressed as a) frequency of open arm entries over the total arm entries (% FEO); b) time spent in them compared with total time the animal stayed in the EPM (% TSO) and c) time spent in closed arms (TSC). Because DEHP has anti-androgenic action we also tested control and exposed immature male rats pretreated with testosterone. We found sex differences in behavior induced by DEHP; while male rats of 45 and 60 days of age showed a significant decrease in FEO and TSO percentages, as well as an increase in TSC, no changes were observed in anxiety-like behavior in perinatal DEHP exposed females at these ages of sexual maturation. In 60-day-old male rats, DEHP exposure produced a significant decrease in serum testosterone levels. Testosterone replacement was able to antagonize the adverse effects of DEHP exposure on LH, activating the negative feed-back mechanism of this steroid on reproductive axis, as well as increasing FEO and TSO percentages to similar values observed in the control group. These findings suggest that the anti-androgenic action of this chemical could be one possible mechanism underlie anxiogenic-like behavior produced by perinatal DEHP exposure in 60-day-old male rats.
Asunto(s)
Antagonistas de Andrógenos/toxicidad , Ansiedad/inducido químicamente , Conducta Animal/efectos de los fármacos , Disruptores Endocrinos/toxicidad , Exposición Materna , Ácidos Ftálicos/toxicidad , Maduración Sexual/efectos de los fármacos , Animales , Femenino , Lactancia/efectos de los fármacos , Masculino , Embarazo , Ratas , Ratas Wistar , Caracteres Sexuales , Testosterona/sangre , Testosterona/farmacologíaRESUMEN
This study investigated the effect of pre and perinatal exposure to di-(2-ethylhexyl) phthalate (DEHP) on the neuroendocrine parameters that regulate reproduction in prepubertal male and female rats. DEHP at doses of 3 and 30mg/kgbw/day was administered orally in the drinking water to dam rats since pregnancy onset until the moment of pups sacrifice at 15 days of age. In these animals gonadotropin serum level and the hypothalamic contents of the amino acids aspartate, glutamate and gamma-aminobutyric acid were determined. No changes in gonadotropin levels and amino acid neurotransmitters were detected at the low dose in both sexes. However, DEHP administered at high dose (30mg/kgbw/day) to dams produced a significant decrease in the inhibitory neurotransmitter GABA and an increase in the stimulatory neurotransmitter aspartate in prepubertal male offspring rats. These modifications were accompanied by gonadotropin serum levels increase. On the contrary, in treated female rats this chemical increased both, aspartate and GABA, which exert a characteristic stimulatory action on gonadotropin in 15-day-old normal females. This study provides new data about changes produced by DEHP on the hypothalamic amino acid neurotransmitters involved in the neuroendocrine reproductive regulation, in prepubertal male and female rat offspring from dams exposed during gestational and lactational periods. These alterations induced by DEHP exposure could be related to the gonadotropin modifications also described in this work, and with changes in the production of sexual hormones previously reported by other authors.
Asunto(s)
Dietilhexil Ftalato/toxicidad , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Lactancia/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Plastificantes/toxicidad , Efectos Tardíos de la Exposición Prenatal , Caracteres Sexuales , Animales , Ácido Aspártico , Relación Dosis-Respuesta a Droga , Femenino , Hormona Folículo Estimulante/metabolismo , Gonadotropinas/metabolismo , Sistema Hipotálamo-Hipofisario/crecimiento & desarrollo , Hormona Luteinizante/metabolismo , Masculino , Exposición Materna , Tamaño de los Órganos/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/crecimiento & desarrollo , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/patología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Ratas , Ratas Wistar , Estadísticas no Paramétricas , Testículo/efectos de los fármacos , Útero/efectos de los fármacos , Ácido gamma-Aminobutírico/metabolismoRESUMEN
BACKGROUND: Treatment with Peg-interferon and ribavirin (PEG-IFN/RBV) for HIV patients co-infected with hepatitis C virus (HCV) genotype 1 has suboptimal rates of response. Viral kinetics has emerged as one of the best prognostic factors of treatment outcome. METHODS: Twenty HIV/HCV genotype 1 co-infected patients in treatment with PEG-IFN/RBV, had blood drawn at baseline, 24 h, 4, 12, 24, 48, and 72 weeks. HCV-RNA levels were evaluated at each time point. ROC curves were used to evaluate the log10 HCV-RNA decay at 24 h that exhibits the best predictive value of achieving response. Genomic characterization of HCV NS5A at both interferon sensitivity-determining region (ISDR) and protein-kinase binding (PKRBD) domains were performed in order to evaluate its heterogeneity and association with 24 h HCV-RNA decay and SVR. RESULTS: Non-responder patients exhibited a mean of 0.7 log10 (SD 0.74 log10) HCV-RNA decay at 24 h, whereas responder-patients presented 1.6 log10 (SD 0.28 log10), p = 0.04. A reduction in HCV viral load from baseline to 24 h of < 1.4 had a negative predictive value for achieving SVR of 100% and a positive predictive value of 50%. HCV genotype 1 isolates from patients with a decrease of HCV-RNA at 24 h > 1.4 log10, exhibited 3.1(SD 1.5) amino acids substitutions in ISDR and 4.8(SD 2.3) in PKRBD regions and 1.6(SD 0.7) and 2.4(SD 1.3), respectively, in those patients presenting lower reduction in HCV-RNA. CONCLUSIONS: HIV/HCV genotype 1 co-infected patients with a decrease in HCV-VL at 24 h > 1.4 log10 are more likely to achieve SVR when treated with PEG-IFN/RBV than those with lower levels of HCV-RNA decay. Along with other host-related and viral-related prognostic factors in HIV/HCV co-infected patients, this very early time point of evaluation could be of relevance in the management of HCV-specific treatment.
Asunto(s)
Antivirales/administración & dosificación , Infecciones por VIH/complicaciones , Hepacivirus/aislamiento & purificación , Hepatitis C/complicaciones , Hepatitis C/tratamiento farmacológico , ARN Viral/sangre , Carga Viral , Adulto , Femenino , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Proteínas Recombinantes , Ribavirina/administración & dosificación , Análisis de Secuencia de ADN , Factores de Tiempo , Resultado del Tratamiento , Proteínas no Estructurales Virales/genéticaRESUMEN
OMC (octyl-methoxycinnamate), an endocrine disruptor having estrogenic activity, is used in sunscreen creams as UV filter. We studied its "in vitro" effects on the hypothalamic release of Gn-RH as well as on the amino acid neurotransmitter system. OMC significantly decreased Gn-RH release in normal male and female rats as well as in castrated rats with substitutive therapy. No effects were observed in castrated rats without substitutive therapy. In males OMC increases the release of GABA, decreasing the production of glutamate (GLU) while in the female decreases the excitatory amino acid aspartate (ASP) and GLU without modifications in the hypothalamic GABA release. These results suggest that OMC acting as endocrine disruptor could alter the sex hormone-neurotransmitter-Gn-RH axis relationships in adult rats.
Asunto(s)
Cinamatos/farmacología , Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Aminoácidos/metabolismo , Animales , Ácido Aspártico/metabolismo , Femenino , Hipotálamo/efectos de los fármacos , Masculino , Ratas , Caracteres Sexuales , Protectores Solares/farmacología , Ácido gamma-Aminobutírico/metabolismoRESUMEN
4-Methylbenzylidene-camphor (4-MBC), an UV-B ray filter, belongs to the endocrine disrupters involved with alterations in the reproductive axis. Our target was to study the effect of 4-MBC on the neuroendocrine parameters that regulate reproduction in prepubertal and peripubertal male rats, which received this disrupter during embryonic and fetal development. 4-MBC was administered (sc) to female rats since pregnancy onset in doses of 20, 100 and 500 mg/kg/day. The litters were sacrificed at 15 or 30 days old to determine testicular weight, gonadotropin and prolactin serum levels and also GnRH and amino acids release from the hypothalamus. The exposure to 20 mg/kg/day only increased the LH serum levels in 30-day-old males. Doses of 100 and 500 mg/kg/day caused a decrease in testicular weight and in LH, GnRH and glutamate levels, in prepubertal rats (15-day-old specimens), and an increase in, gonadotropin (LH and FSH) con-centration and aspartate levels in peripubertal rats (30-day-old specimens), without changes in testicular weight. Prolactinaemia remained unaltered in all groups. Results obtained show that the administration of high doses of 4-MBC during embryonic and fetal stage inhibits the testicular axis in male rats during the prepubertal stage and stimulates it during peripubertad stage. On the other hand in the case of low doses no significant effects were observed.
Asunto(s)
Alcanfor/análogos & derivados , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal/metabolismo , Testículo/efectos de los fármacos , Análisis de Varianza , Animales , Ácido Aspártico/metabolismo , Alcanfor/administración & dosificación , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Femenino , Hormona Folículo Estimulante/sangre , Ácido Glutámico/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Sistema Hipotálamo-Hipofisario/fisiología , Hipotálamo/metabolismo , Hormona Luteinizante/sangre , Masculino , Tamaño de los Órganos , Embarazo , Prolactina/sangre , Ratas , Ratas Wistar , Protectores Solares/administración & dosificación , Testículo/crecimiento & desarrollo , Ácido gamma-Aminobutírico/metabolismoRESUMEN
4-(Methylbenzylidene)-camphor (4-MBC), a UV-B ray filter, is an endocrine disruptors (ED). Our goal was to study the effect of 4-MBC on the neuroendocrine parameters that regulate reproduction in adult female and male rats that received this disrupter during prenatal development. The 4-MBC was administered (sc) to female rats (FO) since pregnancy onset, in doses of 100mg/kg every other day. The litters (F1) were sacrificed at 70 days to determine gonadotrophin serum levels and also GnRH and the amino acids glutamate, aspartate and GABA release from the hypothalamus. The male litter rats (F1) present at adult age a decrease in serum LH and FSH concentration and so also GnRH, excitatory amino acids and GABA hypothalamic secretion. The female litters (F1) rats present at adult age an increase in serum LH and FSH concentration, whereas hypothalamic GnRH release was not modified. In these animals a significant increase of hypothalamic aspartate release as well as GABA secretion decrease were observed. Glutamate secretion was not modified. All these changes were accompanied by an advance (3 days) on the vaginal opening in 4-MBC rats group. In conclusion, prenatal administration of 4-MBC disrupts the gonadal axis in a sexual dimorphic mode that could be connected with the physiological sexual differences in the development of gonadotrophin secretion hypothalamic control mechanisms.
Asunto(s)
Antivirales/farmacología , Farmacorresistencia Viral , Infecciones por VIH/tratamiento farmacológico , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Hepatitis C/virología , Interferón-alfa/farmacología , Ribavirina/farmacología , Proteínas Virales/genética , Antivirales/uso terapéutico , ADN Viral/química , ADN Viral/genética , Infecciones por VIH/complicaciones , Hepatitis C/complicaciones , Humanos , Interferón-alfa/uso terapéutico , Plasma/virología , Ribavirina/uso terapéuticoRESUMEN
OMC (octyl-methoxycinnamate), is an endocrine disruptor with estrogenic activity, which is used in sunscreen creams as a UV filter. We studied its " IN VITRO" effects on the hypothalamic release of LHRH as well as on the amino acid neurotransmitter system in immature rats of 15 (prepubertal) and 30 (peripubertal) days of age. OMC decreased the LH-RH release significantly in male and female rats of both age. In male rats OMC increased the release of GABA while in the female ones It diminished the excitatory amino acid aspartate (ASP) and Glutamate (GLU) without modifications in the hypothalamic GABA release. These results suggest that during sexual maturation the inhibitory effect of OMC on LH-RH release appears to be related to its action on the inhibitory and excitatory amino acid neurotransmitters in male and female rats.
Asunto(s)
Cinamatos/farmacología , Aminoácidos Excitadores/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo/efectos de los fármacos , Maduración Sexual/efectos de los fármacos , Animales , Evaluación Preclínica de Medicamentos , Femenino , Hipotálamo/metabolismo , Masculino , Neurotransmisores/metabolismo , Ratas , Ratas Wistar , Caracteres Sexuales , Protectores Solares/farmacología , Rayos Ultravioleta , Ácido gamma-Aminobutírico/metabolismoRESUMEN
This paper presents the physicochemical and nutrimental characterization of fresh nopal (Opuntia ficus indica, Redonda variety) and nopal powder produced at different stages of development. Nopal powder was obtained by dry vacuum technique using 10(2) Torr and low temperature (40 degrees C). The results showed that the nutrimental and mineral composition of nopal changes as a function of the maturation as follow: The ash content increases from 18.41 for nopalitos (60 g of weight) to 23.24% (nopal pads 200 g); calcium content increases from 1.52 to 3.72%, while phosphorous exhibits an opposite trend: 0.43 to 0.27%, respectively. Calcium oxalate was determined by X-ray diffraction and SEM microscopy and quantified by using atomic absorption spectroscopy. Calcium oxalate decreases from 7.95 to 3.47 mg/g and the Ca/P ratio varies from 3.6 to 11. The soluble fibre decreases from 25.22 to 14.91%, while insoluble fibre increases from 29.87 to 41.65%. These results suggest that nopal could be an important source of minerals within the diets of people in Mexico and the rest of Latin America.
Asunto(s)
Fibras de la Dieta/análisis , Minerales/análisis , Opuntia/química , Extractos Vegetales/química , Calcio/análisis , Oxalato de Calcio/análisis , Análisis de los Alimentos , Humanos , Concentración de Iones de Hidrógeno , Valor Nutritivo , Opuntia/ultraestructura , Fósforo/análisis , Estaciones del Año , VacioRESUMEN
The aim of the present paper was to study the role of NO as a mediator of leptin action at the hypothalamic level during sexual maturation. First, we analyzed the effect of different leptin concentrations (10 (-13), 10 (-11) and 10 (-9) M) on Gn-RH release from anterior preoptic area and medio basal hypothalamus (APOA-MBH) of prepubertal (15 days old) and peripubertal (30 days old) female rats. Leptin 10 (-13) M was the most effective concentration in releasing Gn-RH in both groups of animals. Since glutamate (GLU) and GABA are involved in the hypothalamic control of Gn-RH neurons and also in the neuroendocrine mechanism of puberty, in a second serie of experiments, we evaluated the effect of a competitive inhibitor of nitric oxide synthase (NOS), N-monomethyl-L-arginine (NMMA) on Gn-RH, GLU and GABA release in response to leptin. Co incubation of APOA-MBH with NMMA 0.5 mM, completely blocked Gn-RH and GLU release induced by leptin 10 (-13) M in prepubertal and peripubertal rats. NMMA also blocked the stimulation of GABA release in prepubertal rats, as well as the inhibition of GABA release induced by leptin in peripubertal rats. It can be proposed that the different effect of NO on GABA release, could be related to ontogenic changes, e.g, maturation of receptors and/or interneuronal connections during sexual development. Present results provide evidence that leptin acts at the hypothalamic level to stimulate NO release, which in turn modifies the release of amino acid neurotransmitters involved in Gn-RH control.
Asunto(s)
Hormona Liberadora de Gonadotropina/metabolismo , Leptina/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Maduración Sexual/efectos de los fármacos , omega-N-Metilarginina/farmacología , Aminoácidos/metabolismo , Animales , Femenino , Óxido Nítrico/fisiología , Óxido Nítrico Sintasa/fisiología , Ratas , Ratas WistarRESUMEN
Both increased lymphocyte renewal with subsequent exhaustion of the immune system and impaired T cell renewal have been put into view to account for CD4+ T cell depletion and development of AIDS in HIV-1- infected humans. Telomerase is an enzyme that is involved in mechanisms that control cell life span and replicative potential. The effect of HIV-1 on telomerase activity, certain regulators, and telomeric terminal restriction fragment length on lymphoid Jurkat cells was used in measuring the proliferative activity of T lymphoid cells before and after being infected. At the cellular level, the enzymatic activity remains almost stable but further analyses of fractionated cells revealed that telomerase activity in the nuclear compartment was diminished whereas in the cytoplasmic compartment it was relatively increased on HIV-1 infection. Two key components of telomerase regulation were further considered at the transcriptional level, that is, the mRNA levels of both human telomerase reverse transcriptase (hTERT)--including the relative amount of its alternative splicing variants--and hTR. They were unaffected on HIV-1 infection. Telomeric length was also conserved in infected cells. Overall, these findings demonstrate that HIV-1 infection of Jurkat cells down modulate telomerase activity in the nuclear compartment by affecting its cellular localization.
Asunto(s)
Núcleo Celular/enzimología , Infecciones por VIH/enzimología , Infecciones por VIH/virología , VIH-1 , Linfocitos T/metabolismo , Telomerasa/metabolismo , Regulación hacia Abajo , Humanos , Células Jurkat , Transcripción GenéticaRESUMEN
Resumen: La hipoacusia neurosensorial severa o profunda es un importante handicap o discapacidad que afecta del 1 a 3 por ciento de los recién nacidos vivos y del 2 al 4 por ciento de los neonatos egresados de las UTI neonatales. El pronóstico para el intelecto, condición psico-emocional, lenguaje y desarrollo del habla, es mejor cuando el diagnóstico es efectuado tempranamente y la intervención comienza antes de los 6 meses de vida. La edad habitual deldiagnóstico de hipoacusia es entre los 18 y los 30 meses, o aún más tarde, en casos de pérdida auditiva leve a moderada, cuando no hay implementados programas de screening auditivos. El screening auditivo universal efectuado a los RN, puededarle al niño discapacitado por sordera, la mejor oportunidad para un óptimo cuidado y desarrollo. El criterio universal es necesario, porque cuando el tamizaje es restringido al grupo de neonatos de alto riesgoauditivo, no son diagnosticados entre el 30 y el 50 por ciento de los RNcon pérdida auditiva.
Asunto(s)
Atención Primaria de Salud , Diagnóstico Precoz , Pérdida Auditiva , Pérdida Auditiva Sensorineural , Trastornos de la AudiciónRESUMEN
Resumen: La hipoacusia neurosensorial severa o profunda es un importante handicap o discapacidad que afecta del 1 a 3 por ciento de los recién nacidos vivos y del 2 al 4 por ciento de los neonatos egresados de las UTI neonatales. El pronóstico para el intelecto, condición psico-emocional, lenguaje y desarrollo del habla, es mejor cuando el diagnóstico es efectuado tempranamente y la intervención comienza antes de los 6 meses de vida. La edad habitual deldiagnóstico de hipoacusia es entre los 18 y los 30 meses, o aún más tarde, en casos de pérdida auditiva leve a moderada, cuando no hay implementados programas de screening auditivos. El screening auditivo universal efectuado a los RN, puededarle al niño discapacitado por sordera, la mejor oportunidad para un óptimo cuidado y desarrollo. El criterio ¶universal÷ es necesario, porque cuando el tamizaje es restringido al grupo de neonatos de alto riesgoauditivo, no son diagnosticados entre el 30 y el 50 por ciento de los RNcon pérdida auditiva.(AU)
Asunto(s)
Pérdida Auditiva , Trastornos de la Audición , Pérdida Auditiva Sensorineural , Diagnóstico Precoz , Atención Primaria de SaludRESUMEN
The purpose of the present study was to determine the effect of treatment with leptin on gonadotrophin secretion and hypothalamic GnRH, excitatory and inhibitory amino acids release, in prepubertal (15 days old) and peripubertal (30 days old) male rats. Rats of both ages received a single (ip) injection of 30 microg/kg leptin 60 minutes previous to sacrifice. Serum LH was determined, and the hypothalamus dissected and incubated in Earle's medium. GnRH and amino acids release were determined in the media. LH and GnRH were measured by RIA. Amino acids were assessed by HPLC-UV detection. In the two prepubertal stages, (prepubertal and peripubertal, 15 and 30 days of age respectively) leptin increased plasmatic LH levels (p < 0.01) and hypothalamic GnRH release (p < 0.01). Glutamate (GLU) release showed an increment in leptin-treated rats (p < 0.01) at both ages, while only the 30 days old rats showed an increment of the aspartate (ASP) release. GABA secretion was not modified by leptin treatment. In conclusion, the results demonstrated that leptin stimulates the LH-GnRH axis during sexual development in male rats, increasing the secretion of both hormones. The hypothalamic excitatory amino acid neurotransmitter system appears to be involved in this change.
Asunto(s)
Aminoácidos/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Leptina/farmacología , Hormona Luteinizante/sangre , Maduración Sexual/fisiología , Animales , Ácido Aspártico/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Ácido Glutámico/metabolismo , Hipotálamo/efectos de los fármacos , Masculino , Radioinmunoensayo , Ratas , Ácido gamma-Aminobutírico/metabolismoRESUMEN
The purpose of the present study was to analyse the effect of leptin treatment on the hypothalamic release of GnRH, GABA, and the excitatory amino acids (EAA), aspartate (ASP) and glutamate (GLU) involved in NMDA neurotransmission in prepubertal (15 day old) and peripubertal (30 day old) female rats. The animals were treated with a single dose of leptin (30 microg/kg i.p.) and sacrificed 60 min later. Hypothalamic samples were incubated in Earle's medium; GnRH was determined by RIA and GLU, ASP and GABA by HPLC by UV detection. The hypothalamic release of GnRH was increased by leptin at both ages, the release being significantly higher in peripubertal than in prepubertal rats. The levels of hypothalamic GABA release were different in the two groups; whereas in prepubertal rats the hypothalamic release of GABA increased with leptin administration, the neurotransmitter release decreased in the peripubertal group. On the other hand, the release of ASP was modified only in the peripubertal group, where leptin significantly increased its hypothalamic release. No modifications in leptin-induced hypothalamic release of GLU were observed at the two ages studied. In conclusion, the results showed that leptin increased GnRH release by the hypothalamus of prepubertal and peripubertal rats. In peripubertal rats this increase was accompanied by a significant decrease in the hypothalamic release of GABA as well as an enhanced release of ASP. These results and previous reports suggest that at this stage of sexual maturation, leptin exerts an stimulatory effect on GnRH by inducing release of excitatory amino acids (ASP) and reducing release of inhibitory amino acids (GABA) involved in GnRH control. In prepubertal rats the stimulating effect of the adipocyte hormone on GnRH appears to be related to its stimulative action on GABA which at this age increases GnRH release.
Asunto(s)
Hormona Liberadora de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Leptina/farmacología , Maduración Sexual/fisiología , Aminoácidos/metabolismo , Animales , Femenino , Hipotálamo/efectos de los fármacos , Neurotransmisores/metabolismo , Ratas , Ratas Wistar , Maduración Sexual/efectos de los fármacosRESUMEN
OBJECTIVES: The aim of the present paper was to determine the sensitivity of the GnRH-LH axis to leptin administration during sexual maturation in female rats. METHODS: For this purpose the hypothalamic concentration of GnRH, the pituitary content and the plasmatic levels of LH were determined in prepubertal (15 days of age) and peripubertal female rats (30 days of age), treated with leptin at a dose of 30 microg/kg. i.p. in a single injection, 90 min before sacrifice. RESULTS: The results indicate that leptin significantly increased the GnRH concentration at 15 days of age (p <0.01). At 30 days of age the hormone did not significantly modify the hypothalamic GnRH content. Leptin increased the pituitary LH levels, both in prepubertal and peripubertal rats. Nevertheless, while the increase at 15 days of age was around 180%, in peripubertal rats it was about 51,2 %. In spite that leptin significantly increased LH plasmatic levels at both ages (p < 0.01 ), in rats of 15 days of age leptin increased LH in about 244%, at 30 days of age this increase was only about 102%. CONCLUSION: These results clearly demonstrated that leptin has stimulatory effect on gonadotrophin axis been higher in prepubertal than in peripubertal rats. On these basis, and on the results of previous papers, (in which it has been demonstrated that the hypothalamic control of gonadotrophins by neurotransmitters and neuromodulators also showed qualitative and quantitative changes during sexual maturation), it is proposed that these differences are connected with the maturation of the neuroendocrine mechanisms involved in the regulatory action of leptin on the gonadotrophins axis.
Asunto(s)
Hormona Liberadora de Gonadotropina/metabolismo , Leptina/farmacología , Hormona Luteinizante/sangre , Maduración Sexual/efectos de los fármacos , Maduración Sexual/fisiología , Animales , Femenino , Hipotálamo/metabolismo , Hipófisis/metabolismo , RatasRESUMEN
An arterialized skin flap is defined as a flap harvested from the anterior and distal third of the forearm over a venous pathway. It is composed essentially of skin, subcutaneous tissue, and the subdermal plexus of the veins. The flap is perfused at the recipient side by a donor artery at one end and is connected to one or more regional veins at the opposite end. Since it depends on an atypical blood perfusion, leading to edema, epidermolysis, or even some degree of skin necrosis during the immediate postoperative procedure, this skin flap is considered to have a torpid evolution. This article includes some considerations regarding the enhancing of the arterialized skin flap survival, based on our clinical and laboratory experience after its transplantation. The design, construction of its arterial afferent phase, construction of its venous efferent phase, and monitoring are discussed.
Asunto(s)
Traumatismos de los Dedos/cirugía , Colgajos Quirúrgicos , Anastomosis Quirúrgica , Niño , Traumatismos de los Dedos/patología , Supervivencia de Injerto , Humanos , Microcirugia , Necrosis , Flujo Sanguíneo Regional , Colgajos Quirúrgicos/irrigación sanguínea , Colgajos Quirúrgicos/patologíaRESUMEN
Betalains are important natural pigments for the food industry. The purpose of this study was to evaluate the toxicological and toxicokinetic effects of betalain pigments from a cactaceous fruit (garambullo) on male and female Wistar rats. The pigments did not cause death with any of the doses tested, up to 5 g/kg body weight. In the digestibility studies, there was a degradation of the pigment of 26-29% in the large intestine, 20-26% in the small intestine and 24-29% in the stomach. The pigments were eliminated in the urine as betalains. The pigments had no metabolic effect on the hepatocytes for up to 7 hours. Furthermore, there was no increase in the heart rate when the pigments were administered by oral intubation, up to a dose of 5 g/kg. The data suggest that garambullo fruit pigments do not cause acute toxicity.