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The nerve growth factor (NGF) participates in cell survival and glucose-stimulated insulin secretion (GSIS) processes in rat adult beta cells. GSIS is a complex process in which metabolic events and ionic channel activity are finely coupled. GLUT2 and glucokinase (GK) play central roles in GSIS by regulating the rate of the glycolytic pathway. The biphasic release of insulin upon glucose stimulation characterizes mature adult beta cells. On the other hand, beta cells obtained from neonatal, suckling, and weaning rats are considered immature because they secrete low levels of insulin and do not increase insulin secretion in response to high glucose. The weaning of rats (at postnatal day 20 in laboratory conditions) involves a dietary transition from maternal milk to standard chow. It is characterized by increased basal plasma glucose levels and insulin levels, which we consider physiological insulin resistance. On the other hand, we have observed that incubating rat beta cells with NGF increases GSIS by increasing calcium currents in neonatal cells. In this work, we studied the effects of NGF on the regulation of cellular distribution and activity of GLUT2 and GK to explore its potential role in the maturation of GSIS in beta cells from P20 rats. Pancreatic islet cells from both adult and P20 rats were isolated and incubated with 5.6 mM or 15.6 mM glucose with and without NGF for 4 hours. Specific immunofluorescence assays were conducted following the incubation period to detect insulin and GLUT2. Additionally, we measured glucose uptake, glucokinase activity, and insulin secretion assays at 5.6 mM or 15.6 mM glucose concentrations. We observed an age-dependent variation in the distribution of GLUT2 in pancreatic beta cells and found that glucose plays a regulatory role in GLUT2 distribution independently of age. Moreover, NGF increases GLUT2 abundance, glucose uptake, and GSIS in P20 beta cells and GK activity in adult beta cells. Our results suggest that besides increasing calcium currents, NGF regulates metabolic components of the GSIS, thereby contributing to the maturation process of pancreatic beta cells.
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Glucoquinase , Transportador de Glucose Tipo 2 , Glucose , Células Secretoras de Insulina , Fator de Crescimento Neural , Animais , Masculino , Ratos , Células Cultivadas , Glucoquinase/metabolismo , Glucose/metabolismo , Transportador de Glucose Tipo 2/metabolismo , Insulina/metabolismo , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Fator de Crescimento Neural/metabolismo , Fator de Crescimento Neural/farmacologia , Ratos WistarRESUMO
Testosterone (T), estrogen receptor alpha (ERα), and androgen receptor (AR) play a significant role in the regulation of paternal behavior. We determined the effects of deprivation of paternal care on alterations in paternal behavior, T concentrations in plasma, and the presence of ERα and AR in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BNST), medial amygdala (MeA), and olfactory bulb (OB), as well as the corticosterone (CORT) concentrations in plasma caused by deprivation of paternal care in the Mongolian gerbil (Meriones unguiculatus). Twenty pairs of gerbils were formed; the pups were deprived of paternal care (DPC) in 10 pairs. In another 10 pairs, the pups received paternal care (PC). Ten males raised in DPC condition and 10 males raised in PC conditions were mated with virgin females. When they became fathers, each DPC male and PC male was subjected to tests of paternal behavior on day three postpartum. Blood samples were obtained to quantify T and CORT concentrations, and the brains were removed for ERα and AR immunohistochemistry analyses. DPC males gave less care to their pups than PC males, and they had significantly lower T concentrations and levels of ERα and AR in the mPOA and BNST than PC males. DPC males also had higher CORT concentrations than PC males. These results suggest that in the Mongolian gerbil father's absence causes a decrease in paternal care in the offspring, which is associated with alterations in the neuroendocrine mechanisms that regulate it.
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Receptores Androgênicos , Núcleos Septais , Animais , Feminino , Masculino , Humanos , Gerbillinae/fisiologia , Receptores Androgênicos/metabolismo , Núcleos Septais/metabolismo , Receptor alfa de Estrogênio/metabolismo , Comportamento Paterno/fisiologia , Área Pré-Óptica/metabolismo , Pai , CorticosteronaRESUMO
Maternal malnutrition plays a crucial role in functional development, resulting in behavioral, cognitive, and metabolic abnormalities and disturbances. "Cafeteria diet" has been linked to obesity, metabolic syndrome, diabetes, and other metabolic disruptions in the mammalian lifespan. However, there are very few reports about the effect of intrauterine and early postnatal malnutrition on the circadian rhythm programming of energy metabolites. In mammals, circadian rhythm central control is fundamental for correct interaction with the environment and physiological regulation. Exposure to malnutrition during development imprints metabolic programming throughout life on the central nervous system and peripheral systems. Lifespan studies exploring the effect of high fat/low protein diet administered during critical periods of development are scarce. The present study explored the effect of intrauterine and perinatal malnutrition induced by a high fat/low protein diet (Cafeteria Diet) on circadian and peripheral oscillators controlling glucose, insulin, and triglycerides in rats at 40 and 90 days of age. We evaluated plasma glucose and triglyceride levels in 6 Zeitgeber times, in addition to an intraperitoneal glucose tolerance test (IpTGT) and homeostasis model assessment of insulin resistance (HOMA-IR) at two time-points over 24h. Our results show that offspring of malnourished dams fed cafeteria diet present alterations in circadian rhythmicity of glucose and triglycerides associated with a change in glucose tolerance and insulin sensibility differentially regulated at the development stage and time of day. Intrauterine and early malnutrition due to a cafeteria diet produces maladaptive responses and programs energetic metabolism at several developmental stages during the lifespan.
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Desnutrição , Efeitos Tardios da Exposição Pré-Natal , Gravidez , Feminino , Ratos , Animais , Humanos , Ritmo Circadiano/fisiologia , Insulina , Triglicerídeos , Dieta Hiperlipídica/efeitos adversos , Glucose , MamíferosRESUMO
Methanolic stem bark extracts from ten Mexican Bursera Jacq. ex L. species were evaluated in vitro with regard to their inhibitory activity against two Tenebrio molitor-derived enzymes. Seven extracts (B. bicolor, B. copallifera, B. fagaroides, B. grandifolia, B. lancifolia, B. linanoe, and B. longipes) reduced α-amylase activity by 55.37% to 96.25%, with three samples proving to be particularly potent α-amylase inhibitors (B. grandifolia, B. lancifolia, and B. linanoe; IC50 = 162, 132, and 186 µg/mL, respectively). In contrast, no extract inhibited acetylcholinesterase activity by more than 39.94%. Quantitative HPLC analysis did not reveal any clear correlation between the species-specific flavonoid or phenolic acid profiles and the respective extracts' enzyme inhibitory activity. The findings reported herein do not only contribute to improving the current state of knowledge regarding the enzyme inhibitory potential of the Bursera genus, but could also lead to the development of new sustainable bioinsecticides.
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According to approach-avoidance model, virgin female laboratory rats display maternal behaviour when the tendency to approach and interact with the pup is stronger than avoiding it. A positive neural mechanism that includes the medial preoptic area (mPOA)/bed nucleus of the stria terminalis (BNST) and a negative mechanism that involves the anterior hypothalamic nucleus (AHN)/ventromedial nucleus (VMN)/ periaqueductal grey (PAG) underlie to these behaviours. Unlike virgin rats, which avoid the pups, virgin females Mongolian gerbils (Meriones unguiculatus) can be immediately either maternal or aggressive with the pups. Furthermore, the Mongolian gerbil is monogamous and biparental species. Despite these difference, we hypothesised that maternal and aggressive interaction with the pups could activate mPOA/BNST and AHN/VMH/PAG, respectively, and that maternal response could be associated with high concentrations of estradiol (E2). Twenty virgin maternal females and 20 aggressive toward the pups were selected. Ten maternal females interacted with the pups (MAT-pups) and 10 with candy (MAT-candy). Of the 20 aggressive females, 10 interacted with the pups (AGG-pups) and 10 with candy (AGG-candy). Immediately after the test, blood samples were taken to quantify E2. The brains were dissected for c-Fos immunohistochemistry. MAT-pups females had significantly higher activation in mPOA/BNST than MAT-candy females, while AGG-pups showed significant activation in AHN/VMH/PAG compared with AGG-candy females. The maternal response was associated with high concentrations of E2. These results suggested a positive and a negative mechanism in the regulation of maternal behaviour in the Mongolian gerbil, and that the immediate maternal response could be due to high E2 concentrations.
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Área Pré-Óptica , Núcleos Septais , Animais , Feminino , Ratos , Humanos , Gerbillinae , Área Pré-Óptica/metabolismo , Núcleos Septais/metabolismo , Comportamento Materno/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Petiveria alliacea L. is traditionally used as a folk medical herb in different regions of the world to treat different ailments including those related to the central nervous system. Previous studies have proved that extracts from P. alliacea show improvement in memory and learning process. AIM OF THE STUDY: To study extracts, fractions, subfractions and isolated compounds from P. alliacea on acetylcholinesterase inhibition and antioxidant activity. MATERIAL AND METHODS: Extracts obtained with different polarity solvents and fractions from P. alliacea were evaluated for their inhibitory activity on acetylcholinesterase by Ellman method. This screening allowed the selection of the methanol fraction as the most active and continued a bio-guided study. The compounds identified in methanol fraction were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). Identification of (E)-Tagetone was performed by 1H and 13C NMR spectra. Moreover, the antioxidant activity was evaluated by DPPH and ABTS methods, and the cell viability was assessed by WST-1 method. RESULTS: Two extracts of different polarity were obtained from P. alliacea. The methanol extract and its fraction showed an inhibitory activity on acetylcholinesterase; however, methanol fraction was found to be most potent with 86.5 % AChE inhibition. The methanol fraction also showed antioxidant activity and was not toxic on SH-SY5Y cells. Different compounds including capreoside, narcissin, indane, (-)-isocaryophyllene, (-)-ß-pinene, (E)-tagetone and peonidin 3-O-sambubioside 5-O-glucoside were identified. CONCLUSION: This is the first report indicating that P. alliacea methanol fraction and its subfractions bear acetylcholinesterase inhibition and antioxidant activity properties. This work establishes the basis for further studies in the development of new therapies for neurodegenerative disorders such as Alzheimer 's disease.
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Acetilcolinesterase , Phytolaccaceae , Antioxidantes/farmacologia , Metanol/química , Phytolaccaceae/química , Extratos Vegetais/uso terapêuticoRESUMO
This study aimed to provide evidence on estrogen and androgen pathways regulating the Mongolian gerbil's paternal and infanticidal behaviors (Meriones unguiculatus). We analyzed estrogen receptor alpha (ERα) and androgen receptor (AR) distribution in the medial preoptic area (mPOA), the bed nucleus of stria terminalis (BNST), as well as the anterior hypothalamic nucleus (AHN), the ventromedial hypothalamus nucleus (VMH), and the periaqueductal gray area (PAG) nuclei activated when males interact paternally or aggressively with the pups, respectively. Twenty aggressive males towards the pups and 10 paternal were selected through a screen paternal behavior test. Three groups of 10 males each were formed: paternal males (PAT), males with testosterone (T)-induced paternal behavior (T-PAT), and aggressive males (AGG). Male gerbils could interact with a pup for a few minutes, and their brains were removed and dissected for ERα and AR immunoreactivity (ir). The results showed that in T-PAT and PAT males, the number of ERα-ir and AR-ir cells in the mPOA/BNST was significantly higher than in AGG males. In AGG males, the number of ERα-ir and AR-ir cells in the AHN/VMH/PAG was significantly higher than PAT and T-PAT males. This difference in the presence of ERα and AR in nuclei activated in paternal interactions in the Mongolian gerbil supports the idea that these receptors participate in regulating paternal behavior. Also, these results suggest, for the first time, that they could be involved in the infanticidal behavior in this rodent.
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Agressão/fisiologia , Comportamento Animal/fisiologia , Receptor alfa de Estrogênio/metabolismo , Hipotálamo Anterior/metabolismo , Comportamento Paterno/fisiologia , Substância Cinzenta Periaquedutal/metabolismo , Área Pré-Óptica/metabolismo , Receptores Androgênicos/metabolismo , Núcleos Septais/metabolismo , Animais , Gerbillinae , MasculinoRESUMO
BACKGROUND: A small number of studies have confirmed the presence of oxidative damage in patients with Duchenne muscular dystrophy (DMD). Nevertheless, it is unknown if there a relationship of circulating markers of oxidative stress with a muscle injury. OBJECTIVE: We evaluated if oxidative damage and anti-oxidant markers are associated with muscle damage in DMD. METHODS: This cross-sectional study included 24 patients with DMD classified in ambulatory and non-ambulatory. Markers of muscle damage (creatine kinase [CK]), oxidative damage (malondialdehyde [MDA], and 8-isoprostane), anti-oxidant function (Thiol and mRNA of NRF2 and NF-κB) and nitric oxide (NO) were quantified in circulation. RESULTS: Total NO, MDA, and 8-isoprostane concentrations were significantly (p < 0.05) higher, and thiol concentration was lower in non-ambulatory than ambulatory patients. A significant correlation (p < 0.05) between muscle injury (evaluated by Vignos scale) with CK (r = -0.382), NO (r = 0.444), MDA (r = 0.503), 8-isoprostanes (r = 0.435) and thiol (r = -0.430) was observed. CONCLUSION: These findings suggest that non-ambulatory have high oxidative damage and low anti-oxidant function than ambulatory patients with DMD. Total nitric oxide and oxidative damage plasma markers increase, but the anti-oxidant marker thiol decreases with a muscle injury in boys with DMD. The findings of this study suggest that these markers could be considered as goods indicators of oxidative damage in longitudinal studies to evaluate the muscle injury during DMD progression. Additionally, these findings add new information about the pathophysiology of DMD.
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Músculo Esquelético/lesões , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Adolescente , Antioxidantes/análise , Biomarcadores/metabolismo , Criança , Pré-Escolar , Creatina Quinase/análise , Creatina Quinase/sangue , Estudos Transversais , Dinoprosta/análogos & derivados , Dinoprosta/análise , Dinoprosta/sangue , Feminino , Humanos , Lactente , Masculino , Malondialdeído/análise , Malondialdeído/sangue , México/epidemiologia , Distrofia Muscular de Duchenne/fisiopatologia , Fator 2 Relacionado a NF-E2/análise , Fator 2 Relacionado a NF-E2/genética , NF-kappa B/análise , NF-kappa B/genética , Estresse Oxidativo/fisiologiaRESUMO
De novo hepatic glucose production or hepatic gluconeogenesis is the main contributor to hyperglycemia in the fasting state in patients with type 2 diabetes (T2D) owing to insulin resistance, which leads to at least twice as much glucose synthesis compared to healthy subjects. Therefore, control of this pathway is a promising target to avoid the chronic complications associated with elevated glucose levels. Patients with T2D in the rural communities of Mexico use medicinal plants prepared as infusions that are consumed over the day between meals, thus following this rationale (consumption of the infusions in the fasting state), one approach to understanding the possible mechanism of action of medicinal plants is to assess their capacity to inhibit hepatic glucose production. Furthermore, in several of these plants, the presence of phenolic acids able to block the enzyme glucose-6-phosphatase (G6Pase) is reported. In the present work, extracts of Ageratina petiolaris, Bromelia karatas, Equisetum myriochaetum, Rhizophora mangle, and Smilax moranensis, which are Mexican plants that have been traditionally used to treat T2D, were assayed to evaluate their possible hepatic glucose output (HGO) inhibitory activity with a pyruvate tolerance test in 18-h fasted STZ-NA Wistar rats after oral administration of the extracts. In addition, the in vitro effects of the extracts on the last HGO rate-limiting enzyme G6Pase was analyzed. Our results showed that four of these plants had an effect on hepatic glucose production in the in vivo or in vitro assays. A. petiolaris and R. mangle extracts decreased glucose output, preventing an increase in the blood glucose levels and sustaining this prevented increase after pyruvate administration. Moreover, both extracts inhibited the catalytic activity of the G6Pase complex. On the other hand, even though S. moranensis and B. karatas did not exhibit a significant in vivo effect, S. moranensis had the most potent inhibitory effect on this enzymatic system, while the E. myriochaetum extract only inhibited hepatic glucose production in the pyruvate tolerance test. Because of the traditional method in which diabetic patients use plants, hepatic glucose production inhibition seems to be a mechanism that partially explains the common hypoglycemic effect. However, further studies must be carried out to characterize other mechanisms whereby these plants can decrease HGO.
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Type 2 diabetes (T2D) is a major health problem worldwide. In this condition, the organism can produce insulin but becomes resistant to it; thus the insulin is ineffective. High blood glucose levels are a result of insulin resistance and insulin deficiency; they produce diabetes-associated complications such as kidney failure, blindness, cardiovascular disease, and lower-limb amputation. In Guatemala, there were over 752.700 cases of the disease in 2017 with prevalence of 8.4 (IDF, 2017). The use of plants for medicinal purposes has been practiced in the country since pre-Hispanic times. Among the Cakchiquels, the aerial parts of Hamelia patens Jacq., Neurolaena lobata (L.) R.Br. ex Cass., and Solanum americanum Mill. and the cortex of Croton guatemalensis Lotsy are used to treat type 2 diabetes. The aim of the present study was to confirm the hypoglycemic effect of the plants under normal conditions and under maltose and sucrose tolerance tests, as well as to test the activity of the plant extracts in vitro against alpha-glucosidases types I and II. In agreement with the traditional usage of the plants, in normal conditions without a sugar load, the extracts produced a statistically significant hypoglycemic effect similar to the control drug glibenclamide. When the sugar load was maltose, only Croton and Solanum produced a statistically significant (p < 0.05) hypoglycemic effect compared to the control drug, but when the sugar was sucrose, Croton and Hamelia produced a statistically significant effect (p < 0.05) beginning at 30 min compared to the control group, while Solanum did so at 60 min and Neurolaena at 90 min. In vitro assays showed that the extracts inhibited yeast alpha-glucosidases but not the rat intestinal ones. Of the tested plants, Croton exert an effect both under sugars' tests and under a normal tolerance test; these results suggest the potential use of this plant. The results presented here provided evidence based on the use of these plants as hypoglycemic agents in the treatment of type 2 diabetes.
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Creosote bush, Larrea tridentata (Sesse y Moc. Ex DC, Zygophyllaceae) is a shrub found in the deserts of Northern Mexico and Southwestern United States. In traditional medicine, it is used to treat a variety of illnesses including type 2 diabetes. The present study aims to investigate the effects of creosote bush ethanolic extract on plasma and liver parameters associated with the metabolic syndrome in hamsters fed a high fat and cholesterol diet (HFD), comparing them with those induced by ezetimibe (EZ). Seven groups of six hamsters each were formed. Six groups were fed HFD for 2 weeks. The following 2 weeks, the HFD groups received: (1) only HFD, (2) HFD + 3 mg% EZ, (3) HFD + 0.2% creosote bush ethanolic extract, (4) only standard diet (Std Diet), (5) Std Diet + 3 mg% EZ, (6) Std Diet + 0.2% creosote bush ethanolic extract. The beneficial effects of creosote bush ethanolic extract in the HFD hamster model were a reduction of insulin resistance, associated with lower serum insulin and leptin, lower hepatic lipid peroxidation and higher liver antioxidant capacity. Plasma and liver lipids tended or were reduced to values closer to those of animals fed standard diet. A similar effect on lipids was induced by EZ, although with even lower hepatic cholesterol and total lipids concentrations. In general, the change from HFD to standard diet plus ethanolic extract induced the same but deeper changes, including a reduction in plasma glucose and an increase in the percentage of HDL cholesterol. Unlike creosote bush extract, EZ increased food consumption and neutral fecal steroids, with no significant effect on body weight, epididymal fat pads, liver peroxidation or antioxidant capacity. Also EZ did not modify serum insulin and leptin. However, insulin sensitivity improved to values similar to those induced by the extract. This suggests that the mechanism of action of creosote bush ethanolic extract is different to inhibition of cholesterol absorption or increase excretion. The ethanolic extract of L. tridentata could be useful in the treatment of the metabolic syndrome.
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The formation of cholesterol gallstones involves very complex imbalances, such as alterations in the secretion of biliary lipids (which involves the ABCG5, ABCG8, ABCB4 and ABCB11 transporters), biochemical and immunological reactions in the gallbladder that produce biliary sludge (mucins), physicochemical changes in the structure of cholesterol (crystallization), alterations in gallbladder motility, changes in the intestinal absorption of cholesterol (ABCG5/8 transporters and Niemann-Pick C1L1 protein) and alterations in small intestine motility. Some of these proteins have been studied at the clinical and experimental levels, but more research is required. In this review, we discuss the results of studies on some molecules involved in the pathophysiology of gallstones that may be future therapeutic targets to prevent the development of this disease, and possible sites for treatment based mainly on the absorption of intestinal cholesterol (Niemann-Pick C1L1 and ABCG5/8 proteins).
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Colesterol/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Cálculos Biliares/tratamento farmacológico , Cálculos Biliares/metabolismo , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Anticolesterolemiantes/administração & dosagem , Bile/efeitos dos fármacos , Bile/metabolismo , Previsões , Cálculos Biliares/diagnóstico , Humanos , Proteínas de Membrana Transportadoras/metabolismo , Resultado do TratamentoRESUMO
Obesity is a world problem that requires a better understanding of its physiological and genetic basis, as well as the mechanisms by which the hypothalamus controls feeding behavior. The volcano mouse Neotomodon alstoni develops obesity in captivity when fed with regular chow diet, providing a novel model for the study of obesity. Females develop obesity more often than males; therefore, in this study, we analysed in females, in proestrous lean and obese, the differences in hypothalamus expression of receptors for leptin, ghrelin (growth hormone secretagogue receptor GHS-R), and VPAC, and correlates for plasma levels of total ghrelin. The main comparisons are between mice fed ad libitum and mice after 24 hours of fasting. Mice above 65 g body weight were considered obese, based on behavioral and physiological parameters such as food intake, plasma free fatty acids, and glucose tolerance. Hypothalamic tissue from obese and lean mice was analysed by western blot. Our results indicate that after ad libitum food access, obese mice show no significant differences in hypothalamic leptin receptors, but a significant increase of 60% in the GHS-R, and a nearly 62% decrease in VPAC2 was noted. After a 24-hour fast, plasma ghrelin increased nearly two fold in both lean and obese mice; increases of hypothalamic leptin receptors and GHS-R were also noted, while VPAC2 did not change significantly; levels of plasma free fatty acids were 50% less after fasting in obese than in lean animals. Our results indicate that in obese N. alstoni mice, the levels of orexigenic receptors in the hypothalamus correlate with overfeeding, and the fact that lean and obese females respond in different ways to a metabolic demand such as a 24-hour fast.
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Jejum/fisiologia , Hipotálamo/metabolismo , Obesidade/metabolismo , Receptores de Grelina/metabolismo , Receptores para Leptina/metabolismo , Animais , Peso Corporal , Dieta , Feminino , Grelina/sangue , Hipotálamo/fisiopatologia , Leptina/sangue , Camundongos , Camundongos Obesos , Receptores de Grelina/genética , Receptores para Leptina/genética , Receptores Tipo II de Peptídeo Intestinal Vasoativo/genética , Receptores Tipo II de Peptídeo Intestinal Vasoativo/metabolismoRESUMO
Introducción: el desarrollo científico y tecnológico en las ciencias biológicas y biomédicas ha sido posible gracias a la utilización de modelos animales experimentales. La anemia por deficiencia de hierro (Fe), afecta aproximadamente a la tercera parte de la población mundial. La rata recién destetada ha sido el modelo animal más empleado en la obtención de un biomodelo experimental de anemia. Para la obtención de anemia se utiliza el método de depleción de la hemoglobina (Hb), mediante una alimentación basada en una dieta deficiente en Fe. Objetivo: el objetivo de este trabajo fue evaluar la eficacia de una dieta purificada a partir de caseína en la obtención de ratas anémicas. Métodos: se utilizaron 40 ratas Sprague Dawley recién destetadas (21-24 días), la mitad de cada sexo. Se alojaron en grupos de 3 del mismo sexo en cajas de acero inoxidable con piso de rejillas. Durante 8 semanas se les administró agua desionizada y una dieta de caseína al 12,58 por ciento de proteínas y 1,28 mgFe/Kg. Cada dos semanas se midió el peso corporal y a partir de la cuarta semana, la concentración de Hb. Resultados: se obtuvo un incremento significativo del peso corporal sin observarse diferencias entre hembras y machos. Se tomó como criterio de obtención de la anemia aquellos animales cuya Hb disminuyó al menos en un 30 por ciento del valor inicial promedio por grupo. El porcentaje de animales anémicos a las 8 semanas fue superior en las hembras (75 por ciento), mientras que en machos (60 por ciento). La dieta utilizada en este estudio permitió obtener ratas anémicas en el sexo hembras con una eficiencia aceptable, en relación al porcentaje de animales anémicos y al incremento del peso corporal. Conclusiones: la dieta utilizada en este estudio permitió obtener ratas anémicas en el sexo hembras con una eficiencia aceptable, en relación al porcentaje de animales anémicos y al incremento del peso corporal
Introduction: the scientific and technological development of biological and biomedical sciences has been possible due to the use of experimental animal models. Iron- (Fe-) deficiency anemia affects about one third of the world population. Just weaned rats have been the animal model most commonly used to obtain an experimental biomodel of anemia. The disease is obtained by the hemoglobin (Hb) depletion method, feeding the animal an iron-deficient diet. Objective: evaluate the efficacy of a purified diet based on casein to obtain anemic rats. Method: a study was conducted of 40 just weaned (21-24 days) Sprague Dawley rats, 20 of each sex. The animals were housed in groups of 3 rats of the same sex in stainless steel boxes with mesh bottoms. For 8 weeks the animals were administered deionized water and a casein diet of 12.58 percent protein and 1.28 mgFe/kg. Body weight was measured every two weeks. Hb concentration was gauged from the fourth week onwards. Results: a significant increase in body weight was obtained, with no differences between male and female rats. The criterion for anemia was at least a 30 percent decrease in Hb with respect to the average baseline value per group. The percentage of anemic animals at 8 weeks was higher for females (75 percent ) than for males (60 percent ) Conclusions: the diet used for the study made it possible to obtain female anemic rats with acceptable efficiency in relation to the percentage of anemic animals and the increase in body weight
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Ratos , Anemia Ferropriva , Caseínas/uso terapêutico , Modelos Animais de Doenças , Modelos AnimaisRESUMO
The aim of the present study is to evaluate whether circadian locomotor activity, and the daily profile of plasma parameters related to metabolic syndrome (nutrients: glucose and triacylglycerides, and hormones: insulin and leptin), differ between male and female Neotomodon alstoni mice, both lean and obese. Young adult animals were captured in the field and kept at the laboratory animal facility. After 6 to 7 months feeding the animals ad libitum with a regular diet for laboratory rodents, 50-60% of mice became obese. Comparisons between sexes indicated that lean females were more active than males; however obese females reduced their nocturnal activity either in LD or DD, and advanced the phase of their activity-onset with respect to lights off. No differences in food intake between lean and obese mice, either during the day or night, were observed. Daily profiles of metabolic syndrome-related plasma parameters showed differences between sexes, and obesity was associated with increased values, especially leptin (500% in females and 273% in males) and insulin (150% in both females and males), as compared with lean mice. Our results indicate that lean mice display behavioral and endocrine differences between sexes, and obesity affects the parameters tested in a sex-dependent manner. The aforementioned leads us to propose N. alstoni, studied in captivity, could be an interesting model for the study of sex differences in the effects of obesity.
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Ritmo Circadiano/fisiologia , Obesidade/metabolismo , Obesidade/fisiopatologia , Caracteres Sexuais , Análise de Variância , Animais , Glicemia/metabolismo , Peso Corporal/fisiologia , Modelos Animais de Doenças , Ingestão de Alimentos/fisiologia , Feminino , Insulina/sangue , Leptina/sangue , Masculino , Camundongos , Atividade Motora/fisiologia , Triglicerídeos/sangueRESUMO
Type 2 diabetes is an endocrine disease, which accounts for 9% of deaths worldwide. The aim of oral therapy is to reach normoglycemia to prevent later complications. Among glucose-lowering medications, alpha-glucosidase inhibitors delay the absorption of ingested carbohydrates, reducing the postprandial glucose and insulin peaks. In the present study, we tested the butanolic extracts of four Mexican plants with respect to their alpha-glucosidase inhibition activity, without excluding other possible mechanisms of action. The plants Cecropia obtusifolia Bertol., Equisetum myriochaetum Schlecht & Cham, Acosmium panamense (Benth.) Yacolev and Malmea depressa (Baill) R.E. Fries are used in traditional medicine to treat type 2 diabetes. In previous studies, we have demonstrated these plants' hypoglycemic activity and determined the phytochemical composition of their extracts. Our results in n-STZ diabetic rats loaded with maltose showed that Malmea and Acosmium extracts decreased plasma glucose significantly from 30 min on resembling the effect of acarbose. Cecropia extract produced the highest reduction of plasma glucose, and at 90 min, the glucose level was lower than the fasting level, which suggests another mechanism of action. Equisetum did not exert any effect. In vitro assays of alpha-glucosidase activity showed an IC(50) of 14 microg/ml for Cecropia, 21 microg/ml for Malmea, and 109 microg/ml for Acosmium, which were lower than that of acarbose (128 microg/ml). Equisetum did not show any significant effect on this assay, either. These results contribute to understand the mechanism of action of these plants on glucose metabolism.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Inibidores de Glicosídeo Hidrolases , Fitoterapia , Extratos Vegetais/uso terapêutico , Plantas Medicinais , Animais , Feminino , Masculino , México , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Ratos , Ratos WistarRESUMO
The Harderian glands of rodents are large intraorbital exocrine glands with histologic organization that varies among mammalian species. Here we describe some ultrastructural and biochemical features of the Harderian gland in the Mexican volcano mouse Neotomodon alstoni alstoni, a species of restricted habitat. The Harderian glands from male and female adult mice were dissected, processed and embedded in Epon 812 for light and electron microscopy studies. Porphyrin and total lipids were biochemically determined. The macroscopic appearance of the Harderian gland is similar in the male and female. The gland is a bilobulate structure, situated in the orbit towards the posterior side of the eyeball, of whitish color and is surrounded by a connective tissue capsule. The male gland is slightly heavier (127 mg) than that of the female (113 mg). The Harderian gland shows a tubulo-alveolar organization and is composed exclusively of one type of secretory cells. No branched duct system within the gland was found. Adrenergic nerves endings and mast cell were observed in the interstices of the alveoli. Male and female glands produce similar levels of porphyrins. Triglyceride levels were significantly higher (P < 0.05) in the female compared to the male. Abundance of lipids could induce corneal lubrication of the Harderian gland which may confer a protective and adaptative function to the volcano mouse in its natural habitat during the dry and cold seasons.
Assuntos
Glândula de Harder/metabolismo , Glândula de Harder/ultraestrutura , Muridae/anatomia & histologia , Animais , Feminino , Metabolismo dos Lipídeos , Masculino , México , Microscopia Eletrônica de Transmissão , Muridae/metabolismo , Tamanho do Órgão , Porfirinas/metabolismo , Fatores SexuaisRESUMO
The purpose of the present paper is to review the current knowledge about cholesterol gallstone disease. It is generally accepted that the formation of cholesterol gallstone requires three major pathogenic defect, namely, supersaturation, nucleation and crystal growth as well as disorder of gallbladder motility. The supersaturation is necessary but not sufficient to explain stone formation. It has been suggested that nucleation is the key factor for gallstone formation. However, those three factors are necessary for the formation of cholesterol gallstones, and the presence of just one or two factor does not lead to stones. We also touch briefly on the results form studies performed in Mexico in this area