RESUMEN
After a Telomere Lengthening in juvenile stage, a progressive telomere shortening occurs with age despite higher telomerase level. Telomere Length (TL) may also reflect past physiological state such as a chronic chemical stress. Several studies have revealed a correlation between TL, ageing and/or sex in vertebrates, including teleosts; however, the patterns of telomere dynamics with telomerase mRNA expression, sex, lifespan or chemical stress in teleosts are unclear. The first aim of this study is to verify if telomere length is age and sex-dependent. The second aim is to consider if TL is a useful indicator of stress response in European long-snouted seahorse, Hippocampus guttulatus, an ectothermic and non-model system. We showed that after telomere lengthening during the juvenile stage, a telomeric attrition became significant in sexually mature individuals (p = 0.042). TL decreased in older seahorses despite the presence of somatic telomerase mRNA expression at all life stages studied. There was no difference in TL between males and females, but telomerase mRNA expression was consistently higher in females than males. Exposure to EE2 had no effect on TL in young seahorses, but was correlated with a significant increase in telomerase mRNA expression and various physiological disruptions. Here, a growth retardation of -10 % for body length (p = 0.016) and approximately -45 % for mass (p = 0.001) compared to healthy juvenile seahorses was observed. Our data suggest that telomere dynamics alone should not be used as a marker of EE2 exposure in juvenile seahorses.
Asunto(s)
Smegmamorpha , Telomerasa , Humanos , Masculino , Animales , Femenino , Anciano , Telomerasa/genética , Telomerasa/metabolismo , Smegmamorpha/genética , Smegmamorpha/metabolismo , Homeostasis del Telómero , Telómero/genética , Telómero/metabolismo , ARN MensajeroRESUMEN
Glyphosate-based herbicides are the most frequently used herbicides in the world. We evaluated the effect of Roundup 360 SL on the expression of interleukin-1ß (il-1ß), interleukin-10 (il-10) and heme-oxygenase-1 (ho-1) in the gills, intestines and spleen of young European sea bass (Dicentrachus labrax L.), aged 8 mo. A group of fish was exposed to 647 mg/L of Roundup for 96 h. This treatment did not alter gene expression levels of il-1ß and il-10 cytokine in the intestines, but significantly lowered both levels in the gills (p = 0.02 and p = 0.04 respectively). Expression levels of ho-1 were increased significantly in the three organs of fish from the treated group (the gills p = 0.04, the intestines p = 0.004 and the spleen p < 0.001). These changes may in turn negatively impact the immune system of European sea bass exposed to Roundup.
Asunto(s)
Lubina/genética , Glicina/análogos & derivados , Hemo-Oxigenasa 1/genética , Herbicidas/toxicidad , Interleucina-10/genética , Interleucina-1beta/genética , Contaminantes Químicos del Agua/toxicidad , Animales , Lubina/inmunología , Lubina/metabolismo , Expresión Génica , Glicina/toxicidad , Hemo-Oxigenasa 1/metabolismo , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , GlifosatoRESUMEN
Acute toxicity of Roundup, a commercial glyphosate--based herbicide, was evaluated in a teleost marine fish, the European sea bass, after 96 h of exposure. The LC50 96-h value of Roundup was 529 mg/L. Juveniles (Dicentrarchus labrax L.) were exposed to a sublethal concentration (35% of the LC50, i.e. 193 mg/L) of Roundup for 96-h. The study of heme oxygenase-1 (ho-1) gene expression was performed in four tissues (liver, gills, brain and gonads) and highlighted the disruption of antioxidant defence system. Results showed that ho-1 mRNA levels in liver and gills significantly decreased (p<0.001 and p<0.01 respectively) in fish exposed to 193 mg/L of Roundup, whereas in brain and gonads, ho-1 mRNA level was not altered. The analysis of acetylcholinesterase expression was used to evaluate the overall neurotoxicity of the herbicide and aromatase genes to assess the alteration of the endocrine system. Results showed that AChE and cyp19b gene transcriptions significantly increased (p<0.01) in brain of sea bass, whereas aromatase gene expression (cyp19a) in gonads was not significantly altered. Our results showed complex tissue-specific transcriptional responses after 96 h of exposure to a sublethal concentration. All these disruptions confirmed the deleterious effects of this glyphosate-based herbicide in a marine species.
Asunto(s)
Acetilcolinesterasa/metabolismo , Aromatasa/metabolismo , Lubina/metabolismo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Glicina/análogos & derivados , Hemo-Oxigenasa 1/metabolismo , Herbicidas/toxicidad , Acetilcolinesterasa/genética , Animales , Aromatasa/genética , Lubina/crecimiento & desarrollo , Conducta Animal/efectos de los fármacos , Encéfalo/metabolismo , Europa (Continente) , Branquias/metabolismo , Glicina/toxicidad , Gónadas/metabolismo , Hemo-Oxigenasa 1/genética , Hígado/metabolismo , ARN Mensajero/metabolismo , GlifosatoRESUMEN
One of the most pertinent environmental factors influencing the marine organism life is temperature. It has been demonstrated that an increase of temperature is able to induce the synthesis of heat shock proteins (HSP). In this study we investigated the expression of HO-1 mRNA, also referred to as HSP32, in different tissues of European sea bass (Dicentrarchus labrax, L.) at several time points after increased temperature exposure (from 12degC to 30degC). Our results showed that HO-1 was not expressed in gills, heart, muscle and brain while it was expressed at a basal level in intestine. In liver, spleen and kidneys, HO-1 expression was influenced by temperature increases. In the spleen, we found a significant decrease of the HO-1 expression at the end of 4 weeks. In kidneys a very fast collapse of HO-1 expression level was recorded reaching null value as soon as one hour after exposure to 30degC. In liver, HO-1 expression increased from one hour of exposure to 30degC confirming HO-1 involvement to heat shock response in this organ. This increasing trend reached a 4.5-fold higher value than the initial level after 4 weeks.
Asunto(s)
Lubina/metabolismo , Hemo-Oxigenasa 1/metabolismo , Agua/química , Animales , Hemo-Oxigenasa 1/genética , Mucosa Intestinal/metabolismo , Riñón/metabolismo , Hígado/metabolismo , ARN Mensajero/metabolismo , Bazo/metabolismo , TemperaturaRESUMEN
It has been previously demonstrated that "Warm temperature Acclimation-related 65 kD Protein" (WAP65) is involved in temperature acclimation, response to intoxication and infection, as well as in development. The expression of wap65-1 was investigated in the liver of European sea bass (Dicentrarchus labrax) during exposure to the increased temperature (from 12 deg C to 30 deg C) and during intoxication with four heavy metals: lead, cadmium, copper and zinc. Post temperature increase wap65 expression was highest after one hour at 30 deg C. After 1 to 4 weeks at 30 deg C wap65 transcript levels did not differ from the 12 deg C control group, similar to observations regarding the heat shock protein, hsp70. Upregulation of wap65 was detected after treatment (intoxication) with cadmium (0.5 µg/l). In contrast, a slight, but significant down regulation of wap65 was seen after copper (5 µg/l) intoxication. These data indicate that functional analyses of WAP65 are needed to understand the differential regulation of this gene by metals. The role of WAP65 may be similar to that of HSP70, which has generalized functions in responding to certain stressors and maintaining normal cell physiology.
Asunto(s)
Lubina/genética , Proteínas de Peces/genética , Hígado/metabolismo , Metales Pesados/metabolismo , Animales , Regulación de la Expresión Génica , TemperaturaRESUMEN
INTRODUCTION: Histaminergic status can modify adipose tissue (AT) development: histamine-free mice exhibit visceral obesity, and treatments with H3-antagonists reduce body weight gain. However, direct histamine effects on AT remain poorly documented: it has been observed that histamine stimulates lipolysis in rodent adipocytes when its oxidation by amine oxidases (AOs) is blocked by inhibitors such as semicarbazide. OBJECTIVE: The aim of this work was to study the influence of AOC3 gene invalidation, encoding for semicarbazide-sensitive AO (SSAO), on histamine oxidation and on histamine lipolytic activity in AT. MATERIALS AND METHODS: Expression of AOC- and MAO-encoding genes was determined by real-type PCR in wild-type (WT) and SSAO-deficient (AOC3-KO) mice. Lipolysis was assessed by glycerol release in isolated adipocytes and AO activity by substrate-induced hydrogen peroxide formation in kidney, ileum and AT. RESULTS: The expression levels of the genes encoding AOC1, AOC2 or MAOA and MAOB were not modified in the AT of AOC3-KO mice. In WT mice, histamine oxidation was lower than that of the reference SSAO-substrate benzylamine in AT, but not in ileum. The order of magnitude regarding benzylamine oxidation was AT > ileum >> kidney. In AOC3-KO mice, benzylamine oxidation was abolished in all tissues, while histamine oxidation was abolished in AT but not in ileum. Histamine was inactive on lipolysis in WT but stimulated lipolysis in fat cells from AOC3-KO mice, without reaching the maximal intensity of beta-adrenergic stimulation. CONCLUSION: Histamine was mainly oxidized by diamine oxidase (AOC1 product) in intestine, but by SSAO (AOC3 product) in AT. When protected from its oxidation by SSAO in AT, histamine moderately activated lipolysis in adipocytes in AOC3-KO mice.
Asunto(s)
Tejido Adiposo/enzimología , Tejido Adiposo/metabolismo , Amina Oxidasa (conteniendo Cobre)/genética , Moléculas de Adhesión Celular/genética , Histamina/metabolismo , Adipocitos/efectos de los fármacos , Adipocitos/enzimología , Adipocitos/metabolismo , Animales , Bencilaminas/metabolismo , Bencilaminas/farmacología , Peróxido de Hidrógeno/metabolismo , Lipólisis/genética , Ratones , Ratones Noqueados , Inhibidores de la Monoaminooxidasa/farmacología , Oxidación-Reducción , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Semicarbacidas/farmacologíaRESUMEN
Monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO) activities are very high in white adipose tissue (WAT). SSAO, also known as Vascular Adhesion Protein-1 in vessels, is present at the surface of fat cells and independent approaches have evidenced its impressive increase during adipogenesis. However, the factors that might regulate the expression SSAO and MAO in adipose tissue are still poorly defined. Here, we report the influence of fasting on MAO and SSAO activities in adipose depots. A decrease of MAO activity occurred after three days of starvation in the intra-abdominal adipose tissue (INWAT) of male Wistar rats, regardless of their initial adiposity or fat loss. The reduced fat stores of seven-week old rats, loosing 59 % of INWAT mass during fasting, contained only one half of the MAO activity found in fed control. The same reduction of MAO was observed after prolonged fasting in older rats which lose only 26% of their INWAT during the same starvation duration, leading to a fat mass comparable to that of younger fed control rats. It was therefore the endocrine and metabolic changes occurring during fasting that were responsible for the reduced MAO activity and not the amount of INWAT. Surprisingly, SSAO activity remained unchanged during starvation. In subcutaneous WAT, the changes in MAO and SSAO activities exhibited the same tendencies than those found in INWAT. Taken together, these data show that both MAO and SSAO activities increase in INWAT with age-dependent fattening, and indicate that only MAO diminishes during fasting.
Asunto(s)
Tejido Adiposo Blanco/efectos de los fármacos , Tejido Adiposo Blanco/enzimología , Ayuno/fisiología , Monoaminooxidasa/metabolismo , Semicarbacidas/farmacología , Animales , Glucemia/metabolismo , Peso Corporal/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Masculino , Tamaño de los Órganos/efectos de los fármacos , Oxidación-Reducción , Ratas , Ratas Wistar , Especificidad por Sustrato/efectos de los fármacos , Factores de Tiempo , Tiramina/metabolismoRESUMEN
Visfatin, a protein identified as a secretion product of visceral fat in humans and mice, is also expressed in different anatomical locations, and is known as pre-B cell-colony enhancing factor (PEBF1). It is also an enzyme displaying nicotinamide phosphoribosyltransferase activity (Nampt). The evidence that levels of visfatin correlate with visceral fat mass has been largely debated and widely extended to other regulations in numerous clinical studies and in diverse animal models. On the opposite, the initial findings regarding the capacity of visfatin/Nampt/PEBF1 to bind and to activate the insulin receptor have been scarcely reproduced, and even were contradicted in recent reports. Since the putative insulin mimicking effects of visfatin/Nampt/PEBF1 have never been tested on mature human adipocytes, at least to our knowledge, we tested different human visfatin batches on human fat cells freshly isolated from subcutaneous abdominal fat and exhibiting high insulin responsiveness. Up to 10 nM, visfatin was devoid of clear activatory action on glucose transport in human fat cells while, in the same conditions, insulin increased by more than threefold the basal 2-deoxyglucose uptake. Moreover, visfatin was unable to mimic the lipolysis inhibition induced by insulin. Visfatin definitively cannot be considered as a direct activator of insulin signalling in human fat cells. Nevertheless itsin vivo effects on insulin release and on glucose handling deserve to further study the role of this multifunctional extracellular enzyme in obese and diabetic states.
Asunto(s)
Adipocitos/citología , Regulación de la Expresión Génica , Insulina/metabolismo , Nicotinamida Fosforribosiltransferasa/metabolismo , Células 3T3 , Adipoquinas/metabolismo , Tejido Adiposo/metabolismo , Adulto , Animales , Femenino , Glucosa/metabolismo , Humanos , Ratones , Persona de Mediana Edad , NAD/metabolismoRESUMEN
The liver cDNA encoding heme oxygenase--1 (HO-1) was sequenced from European sea bass (Dicentrarchus labrax) (accession number no. EF139130). The HO-1 cDNA was 1250 bp in nucleotide length and the open reading frame encoded 277 amino acid residues. The deduced amino acid sequence of the European sea bass had 75% and 50% identity with the amino acid sequences of tetraodontiformes (Tetraodon nigroviridis and Takifugu rubripes) and human HO-1 proteins, respectively. A short hydrophobic transmembrane domain at the C--terminal region was found, and four histidine residues were highly conserved, including human his25 that is essential for HO catalytic activity. RT-PCR of mRNA from eight different European sea bass tissues revealed that, in a homeostatis state, the heme oxygenase--1 was abundant in the spleen and liver but not in the brain.
Asunto(s)
Lubina/genética , Proteínas de Peces/genética , Expresión Génica , Hemo-Oxigenasa 1/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Lubina/metabolismo , Sitios de Unión , ADN Complementario/genética , Proteínas de Peces/química , Francia , Hemo-Oxigenasa 1/química , Histidina/química , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Hígado/enzimología , Datos de Secuencia Molecular , Filogenia , Alineación de SecuenciaRESUMEN
The combination of vanadate plus benzylamine has been reported to stimulate glucose transport in rodent adipocytes and to mimic other insulin actions in diverse studies. However, benzylamine alone activates glucose uptake in human fat cells and increases glucose tolerance in rabbits. The aim of this work was to unravel the benzylamine antihyperglycemic action and to test whether its chronic oral administration could restore the defective glucose handling of mice rendered slightly obese and diabetic by very high-fat diet (VHFD). When VHFD mice were i.p. injected with benzylamine at 0.7 to 700 micromol/kg before glucose tolerance test, they exhibited reduced hyperglycemic response without alteration of insulin secretion. Whole body glucose turnover, as assessed by the glucose isotopic dilution technique, was unchanged in mice perfused with benzylamine (total dose of 75 micromol/kg). However, their in vivo glycogen synthesis rate was increased. Benzylamine appeared therefore to directly facilitate glucose utilisation in peripheral tissues. When given chronically at 2000 or 4000 micromol/kg/d in drinking water, benzylamine elicited a slight reduction of water consumption but did not change body weight or adiposity and did not modify oxidative stress markers. Benzylamine treatment improved glucose tolerance but failed to normalize the elevated glucose fasting plasma levels of VHFD mice. There was no influence of benzylamine ingestion on lipolytic activity, basal and insulin-stimulated glucose uptake, and on inflammatory adipokine expression in adipocytes. The improvement of glucose tolerance and the lack of adverse effects on adipocyte metabolism, reported here in VHFD mice allow to consider orally given benzylamine as a potential antidiabetic strategy which deserves to be further studied in other diabetic models.
Asunto(s)
Bencilaminas/administración & dosificación , Diabetes Mellitus Experimental/metabolismo , Glucosa/metabolismo , Hipoglucemiantes/administración & dosificación , Adipocitos/metabolismo , Animales , Bencilaminas/farmacología , Diabetes Mellitus Experimental/complicaciones , Grasas de la Dieta/administración & dosificación , Prueba de Tolerancia a la Glucosa , Hiperlipidemias/metabolismo , Hipoglucemiantes/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/complicaciones , Obesidad/metabolismo , Estrés OxidativoRESUMEN
Beta3-adrenergic agonists have been considered as potent antiobesity and antidiabetic agents mainly on the basis of their beneficial actions discovered twenty years ago in obese and diabetic rodents. The aim of this work was to verify whether prolonged treatment with a beta3-adrenergic agonist known to stimulate lipid mobilisation, could promote desensitization of beta-adrenergic responses. Wistar rats and guinea pigs were treated during one week with CL 316243 (CL, 1 mg/kg/d) by implanted osmotic minipumps. In control animals, beta3-adrenergic agonists were lipolytic in rat but not in guinea pig adipocytes. CL-treatment did not alter body weight gain in both species, but reduced fat stores in rats. Lipolysis stimulation by forskolin was unmodified but responses to beta1-, beta2- and beta3-agonists were reduced in visceral or subcutaneous white adipose tissues of CL-treated rats. Similarly, the beta3-adrenergic-dependent impairment of insulin action on glucose transport and lipogenesis in rat adipocytes was diminished after CL-treatment. In rat adipocytes, [125I]ICYP binding and beta3-adrenoceptor mRNA levels were reduced after sustained CL administration. These findings show that CL 316243 exerts (beta3-adrenergic lipolytic and antilipogenic effects in rat adipocytes. These actions, which are likely involved in the fat depletion observed in rat, also lead to the desensitization of all beta-adrenergic responses. Therefore this desensitization, together with the lack of slimming action in guinea pig, seriously attenuates the usefulness of beta3-agonists as antiobesity agents, and may explain why such agonists have not been conducted to a widespread clinical use.
Asunto(s)
Tejido Adiposo/efectos de los fármacos , Agonistas de Receptores Adrenérgicos beta 3 , Agonistas Adrenérgicos beta/farmacología , Dioxoles/farmacología , Adipocitos Blancos/efectos de los fármacos , Tejido Adiposo/patología , Animales , Regulación hacia Abajo , Etanolaminas/farmacología , Cobayas , Insulina/fisiología , Yodocianopindolol/metabolismo , Masculino , Norepinefrina/farmacología , Ratas , Ratas WistarRESUMEN
Beta3-adrenergic agonists are well-recognited to promote lipid mobilisation and adipose tissue remodeling in rodents, leading to multilocular fat cells enriched in mitochondria. However, effects of beta3-adrenergic agonists on glucose transport are still controversial. In this work, we studied in white adipose tissue (WAT) the influence of sustained beta3-adrenergic stimulation on the glucose transport and on the mitochondrial monoamine oxidase (MAO) activity. As one-week administration of CL 316243 (CL, 1 mg/kg/d) induces beta-adrenergic desensitization in rat but not in guinea pig adipocytes, attention was paid to compare these models. When expressing glucose uptake as nmoles of 2-deoxyglucose/100 mg cell lipids, maximally stimulated uptake was increased in adipocytes of WAT from treated rats but not from treated guinea pigs. However, basal hexose uptake was also increased in CL-treated rats and, as a consequence, the dose-dependent curves for insulin stimulation were similar in control and CL-treated rats when expressed as fold increase over basal. Insulin-induced lipogenesis was unchanged in rat or guinea pig adipocytes after CL-treatment. The glucose carriers GLUT4 and corresponding mRNA were increased in subcutaneous WAT or in brown adipose tissue (BAT) but not in visceral WAT or muscles of CL-treated rats. There was an increase of MAO activity in WAT and BAT, but not in liver, of CL-treated rats while no change was detected in guinea pigs. These findings show that only rat adipocytes, which are beta3-adrenergic-responsive, respond to chronic beta3-AR agonist by an increase of GLUT4 content and MAO activity, despite a desensitization of all beta-adrenoceptor subtypes.
Asunto(s)
Tejido Adiposo/efectos de los fármacos , Agonistas de Receptores Adrenérgicos beta 3 , Agonistas Adrenérgicos beta/farmacología , Dioxoles/farmacología , Transportador de Glucosa de Tipo 4/biosíntesis , Glucosa/metabolismo , Monoaminooxidasa/metabolismo , Adipocitos Blancos/efectos de los fármacos , Tejido Adiposo/patología , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Animales , Regulación de la Expresión Génica/efectos de los fármacos , Cobayas , Insulina/fisiología , Grasa Intraabdominal/metabolismo , Masculino , Ratas , Grasa Subcutánea/metabolismoRESUMEN
Decreased monoamine oxidase (MAO) activity has been observed in adipose tissue of obese patients. Since substrates of MAO and semicarbazide-sensitive amine oxidase (SSAO) can modify adipocyte metabolism, this work investigates whether changes in amine oxidase activity may occur during white adipose tissue (WAT) development. We evaluated MAO and SSAO activities in WAT of high-fat diet (HFD) and low-fat diet fed mice. To distinguish the effect of HFD on its own from the effect of fat mass enlargement, obesity-prone transgenic line of the FVBn strain lacking beta3-adrenergic receptors (AR) but expressing human beta3-AR and alpha2-AR (mbeta3-/-, hbeta3+/+, halpha2+/-) was compared to its obesity-resistant control (mbeta3-/-, hbeta3+/+). As already reported, the former mice became obese while the latter resisted to HFD. No significant change in SSAO or MAO activity was found in WAT of both strains after HFD when expressing oxidase activity per milligram of protein. However, when considering the overall capacity of the fat depots to oxidize tyramine or benzylamine, there was an increase in MAO and SSAO activity only in the enlarged WAT of HFD-induced obese mice. Therefore, the comparison of these models allowed to demonstrate that the higher amine oxidase capacity hold in enlarged fat stores of obese mice is more likely the consequence of increased fat cell number rather than the result of an increased expression of MAO or SSAO in the adipocyte.
Asunto(s)
Tejido Adiposo/enzimología , Amina Oxidasa (conteniendo Cobre)/metabolismo , Grasas de la Dieta/administración & dosificación , Monoaminooxidasa/metabolismo , Obesidad/metabolismo , Amina Oxidasa (conteniendo Cobre)/sangre , Animales , Bencilaminas/metabolismo , Peso Corporal , Radioisótopos de Carbono/metabolismo , Dieta , Susceptibilidad a Enfermedades , Femenino , Ratones , Ratones Transgénicos , Monoaminooxidasa/sangre , Obesidad/etiología , Obesidad/genética , Factores de Tiempo , Tiramina/metabolismoRESUMEN
Repeated administration of benzylamine plus vanadate have been reported to exhibit anti-hyperglycemic effects in different models of diabetic rats. Likewise oral treatment with Moringa oleifera extracts which contain the alkaloïd moringine, identical to benzylamine, has also been shown to prevent hyperglycemia in alloxan-induced diabetic rats. With these observations we tested whether prolonged oral administration of benzylamine could interact with glucose and/or lipid metabolism. Seven week old male Wistar rats were treated for seven weeks with benzylamine 2.9 g/l in drinking water and were submitted to glucose tolerance tests. A slight decrease in water consumption was observed in benzylamine-treated animals while there was no change in body and adipose tissue weights at the end of treatment. Blood glucose and plasma insulin, triacylglycerol or cholesterol levels were not modified. However, benzylamine treatment resulted in a decrease in plasma free fatty acids in both fed and fasted conditions. Benzylamine treatment improved glucose tolerance as shown by the reduction of hyperglycemic response to intra-peritoneal glucose load. Oral benzylamine treatment did not alter the response of adipocytes to insulin nor to insulin-like actions of benzylamine plus vanadate, via in vitro activation of glucose transport or inhibition of lipolysis. This work demonstrates for the first time that oral administration of benzylamine alone influences glucose and lipid metabolism. However, these results obtained in normoglycemic rats require to be confirmed in diabetic models.
Asunto(s)
Bencilaminas/administración & dosificación , Bencilaminas/farmacología , Glucosa/metabolismo , Metabolismo de los Lípidos , Adipocitos/metabolismo , Administración Oral , Animales , Glucemia/metabolismo , Colesterol/sangre , Ingestión de Alimentos , Ácidos Grasos no Esterificados/sangre , Prueba de Tolerancia a la Glucosa , Insulina/sangre , Lipólisis , Masculino , Ratas , Ratas Wistar , Factores de Tiempo , Triglicéridos/sangreRESUMEN
In order to explain complement components abnormalities observed during septic shock, circulating immune complexes (C.I.C.) were searched for in sera from 34 patients with gram negative sepsis by two different methods: polyethylene glycol precipitation test based on physical properties of C.I.C. and C1q deviation test based on the property of radiolabelled C1q to react with C.I.C. Serum immunoglobulins (IgG, IgA, IgM) and complement components (C1q, C3, C4) levels were simultaneously determined. Seventeen patients with minimal haemodynamic abnormalities had normal or increased levels (except C4 at 62% of normal) and in eleven cases both tests for C.I.C. were simultaneously positive. Seventeen patients with severe septic shock had a decrease in IgG, IgM C1q, C3 and C4 and none had both tests for C.I.C. simultaneously positive (P less than 10(-4)). The disappearence of C.I.C. in patients with severe septic shock associated with evidence of complement activation suggests their involvement in the pathogenesis of septic shock in man.
Asunto(s)
Complejo Antígeno-Anticuerpo , Infecciones por Enterobacteriaceae/inmunología , Sepsis/inmunología , Choque Séptico/inmunología , Precipitación Química , Complemento C1 , Proteínas del Sistema Complemento/metabolismo , Humanos , Inmunoglobulinas/metabolismo , PolietilenglicolesRESUMEN
We describe a rapid kinetic method for the automated determination of the xenobiotic-metabolizing enzymes glutathione reductase, glutathione peroxidase and glutathione S-transferase, and its application to the study of cisplatin-induced toxicity. Liver, kidney and urine from control and cisplatin-treated rats were used as the source of enzymes. Advantages over conventional spectrophotometric methods include speed (25 assays in 4 min), small sample size, and improved precision. We show that glutathione S-transferase activity in liver is slightly reduced by cisplatin treatment, whereas all three enzymes are reduced in the kidney. Glutathione-S-transferase activity appeared in urine between the third and seventh days after cisplatin injection. Using these enzyme activities in cisplatin-treated rats, we suggest that the renal enzymes are more sensitive markers of toxicity than hepatic enzymes.
Asunto(s)
Cisplatino/toxicidad , Pruebas Enzimáticas Clínicas/métodos , Glutatión Peroxidasa/análisis , Glutatión Reductasa/análisis , Glutatión Transferasa/análisis , Animales , Autoanálisis , Glutatión Transferasa/orina , Riñón/enzimología , Hígado/enzimología , Masculino , Ratas , Ratas Endogámicas BN , Reproducibilidad de los Resultados , Espectrofotometría/instrumentaciónRESUMEN
In this study we investigated the effect of two molybdenum (Mo) doses (40 and 80 mg/kg/d) on renal function. Neither dose of Mo was able to induce significant hypertension in treated animals. Subchronic exposure to high doses of Mo resulted in a delay in body weight gain associated with mild renal failure marked by a decrease in glomerular filtration. An increase in diuresis and urinary kallikrein excretion associated with unchanged glycosuria and proximal tubular enzymuria (alanine aminopeptidase and gamma-glutamyl transpeptidase) evoked a preferential mild effect at the distal tubule.
Asunto(s)
Lesión Renal Aguda/inducido químicamente , Aminopeptidasas/metabolismo , Calicreínas/orina , Túbulos Renales/efectos de los fármacos , Molibdeno/toxicidad , gamma-Glutamiltransferasa/metabolismo , Lesión Renal Aguda/enzimología , Lesión Renal Aguda/metabolismo , Animales , Biomarcadores/orina , Presión Sanguínea/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Antígenos CD13 , Relación Dosis-Respuesta a Droga , Tasa de Filtración Glomerular/efectos de los fármacos , Túbulos Renales/metabolismo , Masculino , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas EndogámicasRESUMEN
Octopamine is proposed as a substitution product of synephrine by diverse drug industries that advertise new weight-lowering products or medicinal plants enriched in this biogenic amine. We have already reported that octopamine is able to activate in vitro lipolysis in rat adipocytes via beta3-adrenergic receptor activation, while it activates glucose uptake in human fat cells via its oxidation by amine oxidases. In this work, we tested whether a chronic challenge with octopamine could exert anti-obesity effects. A treatment consisting in daily i.p. administration of octopamine (81 micromol/kg) was compared on a four-week period with calorie restriction in the genetically obese Zucker rat. Octopamine treatment resulted in a 19% decrease in body weight gain, when compared to the 177 g gained by controls during the same period. The decrease in body weight gain was detectable only after three weeks of treatment and was apparently not due to a pronounced and sustainable anorectic effect of octopamine since: 1) cumulated food consumption was only reduced by 10%; 2) the experimental 18% reduction of food intake provoked a rapid decrease in body weight gain, significant in less than two weeks. The lipolytic responses to isoprenaline or octopamine and the stimulation of glucose transport by insulin or by the amine oxidase substrate tyramine were unmodified by the treatments. Noteworthy, the elevated plasma insulin of obese rats was lowered by octopamine. This study shows that octopamine can reduce body weight gain in obese rats, without apparent adverse effects, but with less efficacy than beta3-AR agonists.
Asunto(s)
Obesidad/tratamiento farmacológico , Octopamina/farmacología , Pérdida de Peso/efectos de los fármacos , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Animales , Glucemia/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Ácidos Grasos no Esterificados/sangre , Privación de Alimentos/fisiología , Glucosa/metabolismo , Glicerol/sangre , Insulina/sangre , Isoproterenol/farmacología , Lipólisis/efectos de los fármacos , Masculino , Obesidad/metabolismo , Ratas , Ratas Zucker , Factores de Tiempo , Triglicéridos/sangreRESUMEN
The biogenic amine tyramine has been reported to stimulate in vitro glucose transport in adipocytes, cardiomyocytes and skeletal muscle, and to improve in vivo glucose utilization in rats. These effects were dependent on amine oxidation, since they were blocked by inhibitors of monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO). We thus tested in this work whether a prolonged treatment with tyramine could improve glucose tolerance in streptozotocin-induced diabetic rats. First, tyramine content of standard rodent chow was determined by HPLC and daily tyramine intake of control rats was estimated to be around 26 micromol/kg body weight. Then, tyramine was administred during 3 weeks in streptozotocin-induced diabetic rats at 29 micromol/kg by daily i.p. injection alone or together with vanadate 0.02 micromol/kg. In another group of diabetic rats, tyramine was subcutaneously delivered at 116 micromol/kg/day by osmotic minipumps. All tyramine treatments resulted in a decrease of the hyperglycemic responses to an i.p. glucose load. Adipocytes isolated from either untreated or treated diabetic rats were sensitive to the stimulation of glucose uptake by tyramine. However, diabetic animals receiving tyramine for three weeks did not recover from their hyperglycemia, hypoinsulinemia and glucosuria. These results show that the improvement of glucose tolerance induced by prolonged tyramine administration occurs in an insulin-depleted model and probably results from peripheral insulin-like actions of the oxidation of MAO/SSAO substrates, such as the stimulation of glucose uptake into adipocytes.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Glucosa/metabolismo , Tiramina/farmacología , Adipocitos/metabolismo , Animales , Glucemia/análisis , Glucemia/efectos de los fármacos , Prueba de Tolerancia a la Glucosa , Bombas de Infusión , Inyecciones Intraperitoneales , Insulina/farmacología , Masculino , Ratas , Ratas Wistar , Vanadatos/farmacologíaRESUMEN
24 h urinary alanine-amino-peptidase (AAP) and gamma-glutamyl transferase (GGT) activities were studied from the 3rd-7th month of life in male Wistar rats. A close relationship was found between AAP and GGT activity, except at the beginning and at the end of this period. At the end there appear 2 subgroups, the larger (70%) showing a strong correlation between AAP and GGT activity and the other (30%), demonstrating no correlation at all. A good correlation between AAP and GGT activities, creatinine, 24 h urine volume and 24 h creatinine output was found.