RESUMEN
To better understand the role of atrial natriuretic peptide (ANP) in the central regulation of hydro-mineral homeostasis, we analysed its expression in rat hypothalamic neurones during gestation and postpartum. These physiological events are characterized by opposing body fluid regulations. Quantitative in situ hybridization analysis showed that starting from mid-pregnancy, ANP mRNA declined in neurones of the preoptic area, periventricular area, lateral hypothalamus and endorhinal nucleus, and remained low at postpartum. By contrast, magnocellular cells in the supraoptic nucleus (SON) showed four- and 10-fold more ANP mRNA in sections from preterm and postpartum rats, respectively, compared to nonpregnant controls (P < 0.001). Oxytocin mRNA paralleled ANP mRNA expression in the SON, whereas vasopressin mRNA rose in early pregnancy and declined thereafter. High hypothalamic ANP concentration at day 21 of gestation versus nonpregnant rats (3.1 +/- 0.5 versus 1.8 +/- 0.4 ng/mg protein, P < 0.05) suggested that ANP transcript accumulation in the SON is associated with increased utilization of the peptide. The elevation of hypothalamic ANP (two-fold) and ANP receptors by treatment of ovariectomized rats with 17beta-oestradiol (25 micro g/rat, 10 days) was abolished by coadministration of progesterone. Thus, we concluded that elevated oestradiol at term stimulates ANP synthesis and paracrine ANP activation in the hypothalamus. Overall, we provide experimental, anatomical and molecular evidence for ANP regulation in hypothalamic neurones at preterm and after 17beta-oestradiol stimulation. Our study supports the concept that ANP expressed in the SON acts as a peptidergic neurotransmitter involved in water and salt regulation during pregnancy and postpartum.
Asunto(s)
Factor Natriurético Atrial/metabolismo , Neuronas/metabolismo , Preñez/metabolismo , Núcleo Supraóptico/metabolismo , Equilibrio Hidroelectrolítico/fisiología , Adaptación Fisiológica , Animales , Factor Natriurético Atrial/genética , Estradiol/fisiología , Femenino , Hipotálamo/citología , Hipotálamo/metabolismo , Oxitocina/genética , Oxitocina/metabolismo , Embarazo , Progesterona/fisiología , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Reproducción/fisiología , Núcleo Supraóptico/citologíaAsunto(s)
Deficiencia de Glucosafosfato Deshidrogenasa/genética , Alelos , Secuencia de Bases , Côte d'Ivoire/epidemiología , Análisis Mutacional de ADN , Femenino , Sangre Fetal , Frecuencia de los Genes , Genotipo , Deficiencia de Glucosafosfato Deshidrogenasa/epidemiología , Humanos , Recién Nacido , Masculino , Datos de Secuencia Molecular , Mutación Puntual , PrevalenciaRESUMEN
G6PD genotypes were determined in Brazzaville (Congo) on 188 HbSS patients (109 females, 79 males) and 210 controls (115 females and 95 males) with HbAA. DNA samples were analyzed by the polymerase chain reaction (PCR). The frequencies of G6PD B, A+ and A- alleles were 56.9, 20.8 and, 22.2% in the patients versus 56.3, 21.2 and, 22.5% in the controls, respectively. The prevalence of G6PD genotypes in HbSS did not differ (p > 0.05) from that found in the controls. Prevalence of G6PD deficiency did not change when patients were stratified by age, suggesting that there is no advantage of the association of G6PD deficiency with HbSS. Red blood cell count, mean corpuscular volume and mean corpuscular hemoglobin were not modified by the G6PD genotypes, while Hb level was lower in HbSS with G6PD A-. Our study suggests that in Congo, G6PD deficiency does not offer any biological advantage to sicklers.
Asunto(s)
Anemia de Células Falciformes/complicaciones , Deficiencia de Glucosafosfato Deshidrogenasa/complicaciones , Deficiencia de Glucosafosfato Deshidrogenasa/genética , Adolescente , Adulto , Factores de Edad , Anemia de Células Falciformes/sangre , Anemia de Células Falciformes/epidemiología , Niño , Preescolar , Congo/epidemiología , Femenino , Frecuencia de los Genes , Genotipo , Deficiencia de Glucosafosfato Deshidrogenasa/epidemiología , Hemoglobina A , Homocigoto , Humanos , Lactante , Recién Nacido , Masculino , Fenotipo , Reacción en Cadena de la Polimerasa/métodos , Prevalencia , Distribución por SexoRESUMEN
Hb Les Andelys [alpha83(F4)Leu-->Pro] is a mildly unstable variant that was found during glycated hemoglobin measurement in a French family. In this hemoglobin molecule the affected site, in the alpha chain, and the amino acid substitution are identical to those of Hb Santa Ana, an unstable beta chain variant. The structural abnormality was demonstrated by protein chemistry methods, involving, in addition to the classical techniques, a selective precipitation of the abnormal hemoglobin by isopropanol and a mass spectrometry analysis of the alphaT-9 peptide following carboxypeptidase digestion. DNA sequencing demonstrated that the mutation was CTG-->CCG at codon 83 of the alpha2 gene.
Asunto(s)
Globinas/genética , Hemoglobinas Anormales/aislamiento & purificación , Mutación Puntual , Secuencia de Aminoácidos , Electroforesis de las Proteínas Sanguíneas , Niño , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Codón/genética , Análisis Mutacional de ADN , Diabetes Mellitus Tipo 1/sangre , Femenino , Hemoglobina Glucada/análisis , Hemoglobinas Anormales/química , Hemoglobinas Anormales/genética , Humanos , Focalización Isoeléctrica , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Desnaturalización Proteica , Análisis de Secuencia de ADNAsunto(s)
Encéfalo/metabolismo , Virus de la Leucemia Murina , Malaria Cerebral/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Murino/metabolismo , Plasmodium berghei , Animales , Encéfalo/parasitología , Encéfalo/virología , Femenino , Espectroscopía de Resonancia Magnética , Malaria Cerebral/complicaciones , Ratones , Ratones Endogámicos C57BL , Síndrome de Inmunodeficiencia Adquirida del Murino/complicacionesRESUMEN
The retrovirus LP-BM5 murine leukemia virus induces murine AIDS in C57BL/6 mice that has many similarities with human AIDS; Plasmodium berghei ANKA causes experimental cerebral malaria in the same strain of mice. The outcome of malaria infection was studied in mice concurrently infected with the two pathogens. The retrovirus significantly reduced the gravity of the neurological manifestations associated with Plasmodium berghei ANKA infection. The protection against experimental cerebral malaria induced by murine AIDS increased with duration of viral infection and, hence, with the severity of the immunodeficiency. Interleukin 10, principally from splenic T cells, was shown to play a crucial role in this protection.
Asunto(s)
Antígenos CD4/análisis , Interleucina-10/farmacología , Virus de la Leucemia Murina , Activación de Linfocitos , Malaria Cerebral/prevención & control , Síndrome de Inmunodeficiencia Adquirida del Murino/fisiopatología , Plasmodium berghei , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Secuencia de Bases , Cartilla de ADN , Virus Defectuosos/aislamiento & purificación , Femenino , Genoma Viral , Humanos , Virus de la Leucemia Murina/aislamiento & purificación , Malaria Cerebral/inmunología , Malaria Cerebral/patología , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Síndrome de Inmunodeficiencia Adquirida del Murino/inmunología , Síndrome de Inmunodeficiencia Adquirida del Murino/patología , Reacción en Cadena de la Polimerasa , Linfocitos T Colaboradores-Inductores/efectos de los fármacosRESUMEN
Red blood cell (RBC) negative charges and resistance to linoleic acid (LNA)-induced lysis were studied in Plasmodium yoelii-infected mice and in malaria (P. falciparum)-affected individuals. RBCs from mice infected with P. yoelii showed a progressive decrease in the net surface negative charges at 24 h after infection, reaching a minimal value on day 3, followed by a second phase that was characterised by a recovery to normal levels on day 6. Resistance to linoleic acid follows similar kinetics. These alterations preceded the appearance of parasites in the peripheral blood. A similar increase in LNA-induced lysis was observed in RBCs from malaria-affected individuals. These early membrane alterations of uninfected RBCs could be responsible for spreading of infection and RBC lysis during infection.
Asunto(s)
Eritrocitos/metabolismo , Malaria/sangre , Plasmodium yoelii , Adulto , Animales , Electroquímica , Electroforesis , Membrana Eritrocítica/metabolismo , Eritrocitos/efectos de los fármacos , Femenino , Hemólisis/efectos de los fármacos , Humanos , Técnicas In Vitro , Ácido Linoleico , Ácidos Linoleicos/farmacología , Malaria/parasitología , Malaria Falciparum/sangre , Malaria Falciparum/parasitología , Masculino , Ratones , Ratones Endogámicos BALB C , Persona de Mediana EdadRESUMEN
The effect of microtubule disruption on the development and maintenance of cell polarity was studied in rat hepatocytes cultured as primary monolayers in the presence of colchicine or nocodazole. Addition of colchicine immediately after plating did not inhibit the generation of bile canaliculi (the apical pole) after 1 day of culture, as judged by electron microscopic examination, and did not allow penetration of Ruthenium Red through the tight junctions. However, the bile canaliculi developed in the presence of colchicine or nocodazole were not fully normal since they were not able to concentrate fluorescein diacetate in their lumina, and did not enrich with proteins of the apical plasma membrane domain, as control cells did. When the drugs were added after 1 or 2 days of culture, the new bile canaliculi appeared to be unaffected when examined by electron microscopy, but many of them did not concentrate fluorescein and were not enriched with apical membrane proteins within 4 to 24 h after drug addition. Whenever the drugs were added, the proteins that would normally concentrate on the membrane of the bile canaliculi accumulated intracellularly in endocytic vesicles after 2 to 4 h of drug treatment, and in vacuoles resembling lysosomes when the drugs were maintained for 24 h or more. These results show that microtubule disruption does not inhibit the structural reconstitution of bile canaliculi, but impairs their normal function and the transport of proteins of the apical plasma membrane domain.