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Resumen OBJETIVOS: Determinar la repercusión de la diabetes pregestacional, con hiperglucemias moderadas, en el rendimiento reproductivo de la rata, crecimiento, desarrollo y morfología embrionaria en ratas Wistar. MATERIALES Y MÉTODOS: Estudio longitudinal, prospectivo y experimental efectuado en la Unidad de Investigaciones Biomédicas de la Universidad de Ciencias Médicas de Villa Clara, Cuba, en un modelo de diabetes moderada inducida neonatalmente a crías hembras de ratas Wistar de dos días de nacidas mediante la administración subcutánea de 100 mg/kg de peso corporal de estreptozotocina en una única dosis. A los 120 días de nacidas, las ratas de ambos grupos de experimentación (diabético y control) se aparearon con machos sanos. Se determinaron el peso y la glucemia durante la gestación y a los 11.5 días se practicó la cesárea. Se analizaron las variables del rendimiento reproductivo materno y de crecimiento, desarrollo y morfología externa en los embriones. Acorde con los desenlaces se utilizaron pruebas no paramétricas para el análisis de las variables cuantitativas y la prueba de χ2 para las variables cualitativas. RESULTADOS: La hiperglucemia moderada pregestacional provocó modificaciones en la ganancia de peso de la madre, la cantidad de reabsorciones, sitios de implantación, pérdidas preimplantación y eficiencia de implantación, así como en la morfología, talla y cantidad de somitas en los embriones. CONCLUSIONES: La diabetes moderada pregestacional alteró el rendimiento reproductivo materno y el crecimiento y desarrollo intrauterino de la descendencia en etapa embrionaria. La embriopatía diabética se manifestó, además, con malformaciones del sistema nervioso central.
Abstract OBJECTIVES: Diabetes mellitus is one of the most frequent disorders of pregnancy with adverse consequences for the mother and a high risk of diabetic embryopathy in the offspring. The objective of the research was to determine the effect of pregestational diabetes with moderate hyperglycemia on maternal reproductive performance, growth, development and embryonic morphology in Wistar rats. MATERIALS AND METHODS: Longitudinal, prospective and experimental study carried out at the Biomedical Research Unit of the University of Medical Sciences of Villa Clara, Cuba. A model of neonatally induced moderate diabetes was used in female Wistar rat pups two days old, by subcutaneous administration of 100 mg/kg of body weight of streptozotocin in a single dose. At 120 days after birth, rats from both experimental groups (diabetic and control) were mated with healthy males. Weight and glycemia were determined during pregnancy and at 11,5 days the cesarean section was performed. The variables of maternal reproductive performance and of growth, development and external morphology in the embryos were analyzed. According to the results, non-parametric tests were used for the analysis of the quantitative variables and the Chi-square test for the qualitative variables. RESULTS: Moderate pregestational diabetes caused changes in maternal weight gain, number of resorptions, implantation sites, preimplantation loss, and implantation efficiency, as well as in morphology, size, and number of somites in embryos. CONCLUSIONS: Moderate pregestational diabetes altered maternal reproductive performance and intrauterine growth and development of embryonic offspring. Diabetic embryopathy was also manifested by malformations of the central nervous system.
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Introducción: Debido a sus propiedades químicas, la estreptozotocina es uno de los agentes diabetogénicos más utilizados para generar modelos biológicos de diabetes, por lo que es necesario estudiar cuáles son sus efectos en el organismo del animal de laboratorio. Objetivo: Evaluar, en un periodo de 90 días, los efectos de la inyección neonatal de estreptozotocina en ratas Wistar sobre indicadores bioquímicos y de estrés oxidativo en hígado y riñón. Métodos: La diabetes fue inducida neonatalmente por 100 mg de estreptozotocina en ratas Wistar. Se realizaron determinaciones de glucemia, insulina e indicadores de estrés oxidativos en hígado y riñón en cinco animales por grupo a los días 5, 10, 20, 30, 60, 90 de nacidos. Resultados: En todas las intervenciones, la glucemia e insulina mostraron diferencias significativas en el grupo-STZ respecto al control. El valor máximo de hiperglucemia se observó al quinto día. La concentración de nitratos y nitritos en hígado fue mayor que en riñón. En comparación con el grupo control, en el tejido hepático del grupo-STZ la concentración de nitratos y nitritos resultó significativamente superior los días 10-20. En todas las intervenciones se detectó consumo de glutatión reducido en ambos órganos. En el hígado de las ratas STZ no se demostró daño a lípidos ni proteínas; sin embargo, en riñón se detectó daño significativo en ambas biomoléculas al quinto día. Conclusiones: Tanto la citotoxicidad de la estreptozotocina neonatal como las concentraciones de glucosa e insulina inducidas repercutieron negativamente sobre los indicadores de estrés oxidativo estudiados en tejido hepático y renal(AU)
Introduction: Streptozotocin is currently one of the most used diabetogenic agents to generate biological models of diabetes due to its chemical properties, so it is necessary to study the consequences of STZ for the organism of the laboratory animal. Objective: To evaluate in a period of 90 days the effects of neonatal injection of streptozotocin in Wistar rats on biochemical indicators and oxidative stress in liver and kidney. Methods: Diabetes was induced neonatally by 100 mg of streptozotocin in Wistar rats. Blood glucose, insulin and oxidative stress indicators in liver and kidney were determined in 5 animals per group at days 5, 10, 20, 30, 60, 90 of birth. Results: Blood glucose and insulin showed significant differences in the STZ-group respect to the control group in all interventions. The maximum value of hyperglycemia was observed on day-5. The concentration of nitrates and nitrites in liver was higher than in kidney. In liver tissue of the STZ-group, this indicator was significantly higher on days 10-20 compared to the control. In all interventions, reduced glutathione consumption was demonstrated in the STZ-group compared to control in both organs. In the liver of STZ rats no lipid or protein damage was demonstrated. However, in the kidney, significant damage in both biomolecules was detected in the STZ-group on day-5. Conclusions: Neonatal streptozotocin cytotoxicity as well as induced glucose and insulin concentrations had a negative impact on oxidative stress indicators studied in liver and kidney tissue(AU)
Assuntos
Animais , Ratos , Ratos Wistar , Estreptozocina/administração & dosagem , Diabetes Mellitus Experimental/induzido quimicamente , Rim , Fígado , Animais de LaboratórioRESUMO
The aim of this study was to determine the effect of mild hyperglycemia on metabolism during pregnancy, the maternal reproductive performance, and the characteristics of the offspring in neonatal mild diabetic-induced Wistar rats. The experimental diabetes model was generated by neonatal streptozotocin administration (100 mg of streptozotocin/Kg bw/sc) in female Wistar rats. At adulthood, the control and diabetic group were mated. At the 20th day of gestation, a maternal and fetal blood sample were collected for biochemical measurement. The maternal livers, fetal livers, and placenta were removed for oxidative stress measurements. Maternal reproductive outcomes and fetal and placental morphometric measurements were analyzed. The fetuses were classified as small, appropriate, and large for pregnancy age, and examined for the presence of external anomalies. The diabetic group showed mild hyperglycemia, altered glucose tolerance, increased total cholesterol, triglycerides, and hemoglobin A1c during pregnancy. At the 20th day of gestation the diabetic mothers presented increased reabsorptions and embryonic losses before and after implantation, reduced corpora lutea number, litter size, implantation sites, live fetuses, and decreased efficiency of implantation rate. Similarly, the offspring showed reduced fetal, craniofacial, and placental dimensions, in addition to a higher proportion of small fetuses for pregnancy age. Mild hyperglycemia during pregnancy did not generate marked oxidative stress in the mother, and in fetal liver and placenta decreased antioxidant activity was evident by significant consumption of reduced glutathione. Mild diabetes led to a negative impact on maternal reproductive performance and characteristics of the offspring. This experimental model reproduced maternal and fetal outcomes of pregnant rats presenting controlled diabetes. ABBREVIATIONS: bw: body weight; sc: subcutaneous; DM: diabetes mellitus; STZ: streptozotocin; OGTT: oral glucose tolerance test; ITT: insulin tolerance test; GSH: glutathione; MDA: malondialdehyde; AOPPs: advanced oxidation protein products; TBARs: thiobarbituric acid reaction; SPA: small for pregancy age; APA: appropriate for pregnancy age; LPG: large for pregnancy age; ROS: reactive oxygen species.
Assuntos
Diabetes Mellitus Experimental/complicações , Reprodução , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Anormalidades Congênitas/etiologia , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Implantação do Embrião , Feminino , Morte Fetal , Feto/metabolismo , Hemoglobinas Glicadas/metabolismo , Lipídeos/sangue , Tamanho da Ninhada de Vivíparos , Fígado/metabolismo , Estresse Oxidativo , Placenta/metabolismo , Gravidez , Gravidez em Diabéticas/sangue , Gravidez em Diabéticas/fisiopatologia , Ratos Wistar , Fatores de TempoRESUMO
The present study aimed to investigate, in the streptozotocin-induced mild diabetic rat model, the zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), and magnesium (Mg) concentration in serum, liver, and kidney tissues, and urine samples from adult Wistar rats treated neonatally with streptozotocin (STZ). Diabetes was induced by subcutaneous administration of streptozotocin (100 mg/Kg) in female Wistar rats of 2 days old (STZ, n = 10). Control group (CG, n = 10) received only sodium-citrate buffer. The mineral concentrations were measured by atomic absorption spectrophotometry. The validity and accuracy were checked by conventional methods. STZ neonatal injection successfully leaded to mild diabetes in the adult rats. Serum concentrations of Zn, Cu, Fe, Ca, and Mg showed no changes (p > 0.05) due to diabetes. The Zn, Fe, Ca, and Mg concentrations in liver and kidney tissues were not different (p > 0.05) between STZ and CG. The mean values of Cu were higher (p < 0.05) in liver and kidney samples from STZ as compared to CG. Urine minerals concentrations (Zn, Cu, Fe and Ca) in STZ-rats group were lower (p < 0.05) than CG. However, the content of all evaluated minerals in the excreted urine were higher (p < 0.01) in STZ-rats during a 24 h collection period. Urinary excretion of Zn, Cu, Fe, Ca, and Mg was strongly correlated with urinary volume during the 24 h period (r > 0.7; p < 0.001). Observed changes in mineral metabolism of STZ-induced mild diabetes model could be due to the endocrine imbalance associated with the diabetic condition.