Navegando por Palavras-chave "Pré-Puberdade"

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    Caracterização dos efeitos adversos de agroquímicos isolados ou combinados e estudo do potencial protetivo de suplemento polivitaminico em ratos machos juvenis
    (Universidade Federal de São Paulo (UNIFESP), 2019-06-17) Garcia, Mariana Simoes [UNIFESP]; Perobelli, Juliana Elaine [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Agrochemicals are the most widely used synthetic chemicals in the world. They have the function of minimizing pests that interfere with the production of the vast majority of agricultural crops. Since 2009, Brazil is the country that uses the biggest amount agrochemicals in the world. Residues from these products contaminates food, soil and water, leading to environmental exposure for the entire world population. Under real conditions, this exposure occurs to complex mixtures of agrochemicals, which may establish synergistic or additive effects to each other, enhancing or adding the consequent health damage. An important pathway of these chemicals is oxidative damage to cellular components generated by excess of free radicals due to an imbalance between the production of these reactive molecules and the natural antioxidant system. In this way, the consumption of multivitamins supplements can be used as a way to increase the antioxidant defense of the organism, mitigating the adverse effects of these toxic agents. In fact, some studies have been investigated thevinjuries caused by chemical mixtures in experimental models, as well as the protective effect of antioxidant agents, but the vast majority uses adult individuals. In this context, the importance of juvenile / pre-pubertal toxicity studies has been highlighted in the recent literature because it is a period of great sensitivity during postnatal development. Given the scarcity of studies and the relevance of the issue, the present study aims to investigate whether pre-pubertal exposures at low doses of Carbendazim, Acefato and Mancozebe, because they are present in greater quantity in the diet of Brazilians, alone or in a mixture, cause immediate repercussions on the reproductive and endocrine parameters of juvenile male Wistar rats. In addition, it evaluates the potential protective effect of co-administration of multivitamins and minerals supplement. For this purpose, rats were exposed to the agrochemicals alone or in mixture (binary or triple) with or without supplementation, orally by gavage, from the postnatal day 23 to 53, when they were euthanized and evaluated for the histomorphometric parameters of testis and epididymis. Serum levels of steroid hormones were evaluated. In summary, the results indicate likely endocrine disrupting action of agrochemicals. Interestingly, isolated agrochemicals appear to exert more pronounced adverse effects than when administered in mixture. However, the group treated with multivitamin supplement did not present a significant protective effect as a form of protection against toxicological effects.
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    Resveratrol melhora a qualidade espermática, a fertilidade e a capacidade reprodutiva de ratos adultos com diabetes tipo1 induzido, na pré-puberdade, pela administração de estreptozotocina
    (Universidade Federal de São Paulo (UNIFESP), 2020-10-05) Simas, Joana Nogueres [UNIFESP]; Valdeolivas, Sandra Maria Miraglia [UNIFESP]; Universidade Federal de São Paulo
    Introduction: Diabetes Mellitus is characterized by a series of metabolic disorders. It is estimated that, in the coming decades, about 628.6 million individuals worldwide may develop the disease. Its pathogenesis progresses with the development of arteriosclerosis, angiopathies, nephropathies and neuropathies. Although conditions in the male reproductive system have already been described, the ultimate impact on the male reproductive outcomes cannot be neglected. Resveratrol, phytoalexin found in plants such as grapes and açai berries, is a powerful antioxidant capable of decreasing glycemic levels and several metabolic effects associated with diabetes mellitus. In previous studies, we observed that chronic treatment with resveratrol improves not only glycemic levels, but also plasmatic levels of testosterone, estradiol and LH, as well as quantitative sperm parameters and sperm morphology in adult animals (75 days postpartum, dpp), which had type 1 diabetes induced by streptozotocin, from prepuberty. Objectives: To investigate the protective action of resveratrol on male reproduction against the damage caused by type 1 diabetes mellitus, induced in prepuberty, with regard to future sperm quality, with an emphasis on the integrity of the DNA and the structure of the sperm chromatin and in the evaluation of the reproductive competence of the animals, when adults. Material and Methods: a hundred and twelve male Wistar rats were used, obtained by mating 15 males and 30 females, aged 12 weeks, which were used as breeders. The male rats, aged 30 days, belonging to these matings, were distributed into 7 groups: Sham control (SC; sodium citrate buffer solution); Resveratrol-vehicle control (RV-carboxymethylcellulose, resveratrol vehicle); Resveratrol (R); Diabetic (D); Diabetic-treated-with-insulin (DI); Diabetic-treated-with-resveratrol (DR); Diabetic-treated-with-insulin + resveratrol (DIR). Type 1 diabetes mellitus (DM1) was induced in animals at 30 dpp with a single intraperitoneal injection of streptozotocin (65 mg / kg). Blood glucose was monitored at 30, 33, 45, 64, 75, 100 and 110 dpp. The DR, DIR and R groups were treated, in the morning, with 150mg of resveratrol / kg of body weight / day (administered by gavage), from 33º dpp to 110º dpp. Animals of DI and DIR groups received subcutaneous injections of NPH (Neutral Protamine Hagedorn) insulin, at a dose of 1U / 100g of body weight / day, from the 5th day of diabetes induction, up to 110dpp. At 100 dpp, all animals were mated with two healthy primiparous females (n = 84) in order to evaluate fertility and gestation rates and reproductive capacity. The males were submitted to euthanasia at 110 dpp to collect the material destinated to sperm analysis and to evaluate testicular and epididymal oxidative stress levels. Qualitative sperm analysis comprised the following tests: a) Comet assay (to investigate DNA fragmentation); b) Acridine orange, to study chromatin and DNA structures and c) Chromomycin A3 (CMA3- for chromatin compaction and protamination analyses); the latter (items b and c) were evaluated using a flow cytometer. We also investigated: sperm motility (using a computerized analysis system); acrosome integrity (PNA-Arachis hypogaea lectin method); the mitochondrial mass (Mitotracker Green probe), as well aspregnancy, fertility and reproductive capacity rates. Results: DM1 significantly altered the qualitative sperm parameters and impaired xvi the fertility and pregnancy rates likewise the reproductive capacity of the animals. Consonant with other reproductive parameters previously evaluated by our group, under the same experimental conditions, the results of this research ratify the beneficial action of resveratrol on reproduction, improving sperm quality in animals with DM1, with regard to motility, mitochondrial mass and acrosomal integrity. Likewise, the administration of insulin and insulin + resveratrol also improved these parameters. The results showed that the treatment also improvemed fertility and pregnancy rates in diabetic rats treated with resveratrol and / or insulin, in relation to untreated diabetics. Conclusion: Considering the positive data regarding the normalization of glycemia in DM1, the reduction of MDA (oxidative stress marker) levels, both in the testis and in the epididymis, the improvement of the quality of sperm DNA and reproductive results in diabetic rats treated with RES, regardless of insulin therapy, we believe that RES could be considered a very promising adjuvant to control glycemic homeostasis and improve the fertility status associated with DM1, alone or in conjunction with insulin therapy.