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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Efeitos do diabetes mellitus sobre a função testicular de ratos Wistar / Study of the diabetes mellitus on testicular function of Wistar rat

Marcia Cury Cioffi 24 October 2006 (has links)
Utilizaram-se 27 ratos Wistar, machos com 98 dias de idade, originados do Biotério da FMVZ-USP, com o objetivo de avaliar os possíveis efeitos do diabetes mellitus, sobre a função reprodutiva relacionada ao macho.Os animais foram divididos em três grupos, grupo A (GA) constituído de 10 animais sadios, grupo B (GB) constituído de oito ratos Wistar, com diabetes mellitus induzida quimicamente através da administração intraperitonial de estreptozotocina (65mg/Kg) e grupo C (GC) constituído por nove animais com diabetes mellitus induzida quimicamente pela administração intraperitonial de estreptozotocina (65mg/Kg), associada a insulinoterapia (3UI/rato por dia). Após quatro dias da administração da droga (GB e GC), os animais pertencentes ao grupo C (GC) receberam insulinoterapia (três IU/rato/dia) durante 42 dias. No final do experimento (46 dias após a administração da estreptozotocina), os animais foram sacrificados e foram observados os seguintes resultados; O diabetes mellitus leva ao aumento da glicemia, diminuição do peso corpóreo, diminuição do peso e tamanho testicular, diminuição das concentrações séricas de testosterona e FSH. Porém através da avaliação dos níveis séricos de inibina B, foi constatado que o diabetes não promove nem redução, nem aumento das concentrações séricas desse hormônio. Conclui-se também que a reposição exógena de insulina foi capaz de impedir a diminuição do peso corporal, redução do peso testicular, diminuição dos níveis de testosterona e FSH, porém apesar da insulinoterapia ter impedido a diminuição do peso corpóreo, não foi capaz de proporcionar o mesmo desenvolvimento corporal observado nos animais controle. / The objective of the present experiment was to evaluate the possible effect of diabetes mellitus, on the reproductive function in male rats. Towards this end, 27 male Wistar rats (98 days old), housed at the FMVZ-USP animal holding facility, were randomly assigned into three groups: Group A (GA) consisting of 10 healthy animals; Group B(GB) consisting of eight Wistar rats, with diabetes mellitus chemically induced through the intraperitoneal administration of estreptozotocin (65mg/Kg); and C group (GC) constituted by nine animals with diabetes mellitus chemically induced by the intraperitoneal administration of estreptozotocin (65mg/Kg), associate to an insulin treatment (3IU/rat per day for 42 days) that begun 4 days after the streptozotocin administration. Animals were euthanized 46 days after the administration of the estreptozotocin and the following results were obtained: diabetes mellitus led to an increase of the glicemia, reduction of the corporeal weight, decreased testicular wheight, serum concentrations of testosterone and FSH. No effect of diabeted were found for the serum levels of inhibin B. Results suggested that the exogen replacement of insulin was capable of hindering the reduction on corporal weight, reduction of testicular weight and reduction of the testosterone levels and FSH. On the other hand despite the fact that insulin treatament was capable of avoiding the reduction on bofy weight, it was not capable to provide similar body development observed in the normal animals.
12

Efeitos do diabetes mellitus sobre a função testicular de ratos Wistar / Study of the diabetes mellitus on testicular function of Wistar rat

Cioffi, Marcia Cury 24 October 2006 (has links)
Utilizaram-se 27 ratos Wistar, machos com 98 dias de idade, originados do Biotério da FMVZ-USP, com o objetivo de avaliar os possíveis efeitos do diabetes mellitus, sobre a função reprodutiva relacionada ao macho.Os animais foram divididos em três grupos, grupo A (GA) constituído de 10 animais sadios, grupo B (GB) constituído de oito ratos Wistar, com diabetes mellitus induzida quimicamente através da administração intraperitonial de estreptozotocina (65mg/Kg) e grupo C (GC) constituído por nove animais com diabetes mellitus induzida quimicamente pela administração intraperitonial de estreptozotocina (65mg/Kg), associada a insulinoterapia (3UI/rato por dia). Após quatro dias da administração da droga (GB e GC), os animais pertencentes ao grupo C (GC) receberam insulinoterapia (três IU/rato/dia) durante 42 dias. No final do experimento (46 dias após a administração da estreptozotocina), os animais foram sacrificados e foram observados os seguintes resultados; O diabetes mellitus leva ao aumento da glicemia, diminuição do peso corpóreo, diminuição do peso e tamanho testicular, diminuição das concentrações séricas de testosterona e FSH. Porém através da avaliação dos níveis séricos de inibina B, foi constatado que o diabetes não promove nem redução, nem aumento das concentrações séricas desse hormônio. Conclui-se também que a reposição exógena de insulina foi capaz de impedir a diminuição do peso corporal, redução do peso testicular, diminuição dos níveis de testosterona e FSH, porém apesar da insulinoterapia ter impedido a diminuição do peso corpóreo, não foi capaz de proporcionar o mesmo desenvolvimento corporal observado nos animais controle. / The objective of the present experiment was to evaluate the possible effect of diabetes mellitus, on the reproductive function in male rats. Towards this end, 27 male Wistar rats (98 days old), housed at the FMVZ-USP animal holding facility, were randomly assigned into three groups: Group A (GA) consisting of 10 healthy animals; Group B(GB) consisting of eight Wistar rats, with diabetes mellitus chemically induced through the intraperitoneal administration of estreptozotocin (65mg/Kg); and C group (GC) constituted by nine animals with diabetes mellitus chemically induced by the intraperitoneal administration of estreptozotocin (65mg/Kg), associate to an insulin treatment (3IU/rat per day for 42 days) that begun 4 days after the streptozotocin administration. Animals were euthanized 46 days after the administration of the estreptozotocin and the following results were obtained: diabetes mellitus led to an increase of the glicemia, reduction of the corporeal weight, decreased testicular wheight, serum concentrations of testosterone and FSH. No effect of diabeted were found for the serum levels of inhibin B. Results suggested that the exogen replacement of insulin was capable of hindering the reduction on corporal weight, reduction of testicular weight and reduction of the testosterone levels and FSH. On the other hand despite the fact that insulin treatament was capable of avoiding the reduction on bofy weight, it was not capable to provide similar body development observed in the normal animals.
13

Effects of nicotine and streptozotocin on the cardiovascular system

Peterson-Wakeman, Robert S. 03 February 2005
Our study investigated the potential for a combination of diabetes and nicotine treatment to affect blood pressure in the rat. We used streptozotocin injection and oral nicotine feeding as models of type-1 diabetes and smoking respectively. Blood pressure was assessed using the indirect tail-cuff technique. In an attempt to further characterize our experimental model, we also observed body weight, plasma glucose and the contractility of aortic segments in various treatment groups. Our data was expressed as mean ± SEM, and significance was regarded as P < 0.05. We found that a combination of streptozotocin and nicotine treatment resulted in a significant elevation of systolic blood pressure compared with either treatment alone, or control. Furthermore, assessment of aortic contractility showed alteration of reactivity to both phenylephrine and sodium nitroprusside as a result of the combination treatment. We also observed a trend for our combination treatment to exacerbate the elevation of plasma glucose level seen in streptozotocin induced diabetic rat models. This study serves as an experimental basis to underline the importance of cessation of tobacco use for individuals with diabetes mellitus.
14

Effects of nicotine and streptozotocin on the cardiovascular system

Peterson-Wakeman, Robert S. 03 February 2005 (has links)
Our study investigated the potential for a combination of diabetes and nicotine treatment to affect blood pressure in the rat. We used streptozotocin injection and oral nicotine feeding as models of type-1 diabetes and smoking respectively. Blood pressure was assessed using the indirect tail-cuff technique. In an attempt to further characterize our experimental model, we also observed body weight, plasma glucose and the contractility of aortic segments in various treatment groups. Our data was expressed as mean ± SEM, and significance was regarded as P < 0.05. We found that a combination of streptozotocin and nicotine treatment resulted in a significant elevation of systolic blood pressure compared with either treatment alone, or control. Furthermore, assessment of aortic contractility showed alteration of reactivity to both phenylephrine and sodium nitroprusside as a result of the combination treatment. We also observed a trend for our combination treatment to exacerbate the elevation of plasma glucose level seen in streptozotocin induced diabetic rat models. This study serves as an experimental basis to underline the importance of cessation of tobacco use for individuals with diabetes mellitus.
15

Hypoglycaemic and renal effects of a bioactive plant extract in streptozotocin induced diabetic rats.

Mapanga, Rudo Fiona. January 2008 (has links)
Background: Evidence from our laboratories indicates that triterpene constituents of Syzygium cordatum (Hochst.) [Myrtaceae] crude leaf extracts can be used to treat diabetes mellitus. For the plant derived triterpenes to have further potential in diabetes management, they should, however, additionally alleviate or prevent some of the complications of diabetes mellitus such as impaired kidney function and cardiovascular disorders. Accordingly, this study was designed to isolate the triterpene, oleanolic acid (OA) from S. cordatum leaves and evaluate its effects on blood glucose, renal function and blood pressure in streptozotocin (STZ)-induced diabetic rats. OA was studied because it is the major constituent of many African plant species used in traditional medicine. Materials and Methods S. cordatum crude leaf ethyl acetate solubles (EAS) were obtained after defatting the leaves with hexane followed by dichloromethane before maceration with ethyl acetate. Preliminary experiments indicated that EAS contained triterpenes with hypoglycaemic properties. Solvent extraction and fractionation of EAS yielded mixtures of oleanolic acid/ursolic acid (OA/UA) and methyl maslinate/methyl corosolate. Recrystallisation of the OA/UA mixture using ethanol yielded OA, the structure of which was confirmed by NMR spectroscopy ('H & 13C). Oral glucose tolerance test (OGTT) responses to various doses of OA (40, 80 and 120 mg/kg) were monitored in separate groups of non-diabetic and STZ-induced diabetic rats given a glucose load (0.86 g/kg, p.o.) after an 18-h fast. Rats treated with deionized water (3 ml/kg p.o.), or standard drugs, (insulin, 200 Hg/kg, s.c; metformin, 500 mg/kg, p.o. and glibenclamide, 500 f^g/kg, p.o.) acted as untreated and treated positive controls, respectively. To investigate the possible interaction between OA and standard drugs in lowering blood glucose, OGTT responses were studied in separate groups of animals simultaneously treated with OA at either 40 or 80 mg/kg and insulin (100 or 200 ug/kg, s.c), metformin, (250 or 500 mg/kg, p.o.) or glibenclamide (250 or 500 mg/kg, p.o.). Blood glucose was monitored at 15-min intervals for the first hour, and hourly thereafter for 3 h. Plasma insulin concentrations were measured in separate parallel groups of rats prepared as for OGTT studies to examine whether there was an association between OA treatment and pancreatic insulin secretion. Acute effects of OA on kidney function and mean arterial blood pressure (MAP) were investigated in anaesthetized rats challenged with hypotonic saline after a 3'/2-h equilibration for 4 h consisting of 1 h control, 1XA h treatment and 1 Vi h recovery periods. OA was added to the infusate during the treatment period. Short-term effects of OA were studied in individually-caged rats treated twice daily with OA (80 mg/kg, p.o.) for 5 weeks. Results OA decreased blood glucose concentrations of both non-diabetic and diabetic rats, as did some standard drugs except glibenclamide which did not exhibit any effects in STZ-induced diabetic animals. The blood glucose lowering effects were most potent in STZ-induced rats treated with combined OA and insulin by comparison with all other treatments. Short-term treatment of non-diabetic and STZ-induced diabetic rats with OA alone for 5 weeks decreased blood glucose concentrations, but the reduction in non-diabetic rats was to values that did not achieve statistical significance. Except for non-diabetic rats treated with insulin alone or in combination with OA, plasma insulin concentrations were not altered by treatment in non-diabetic and STZ-induced diabetic animals. Hepatic glycogen concentrations of non-diabetic and STZ-induced diabetic rats were significantly increased by all treatments at the end of 5 weeks. Acute intravenous infusion of OA in anaesthetized rats significantly increased Na+ excretion outputs of non-diabetic and STZ-induced diabetic rats without affecting urine flow, K+ or CI" excretion rates. Similarly, daily OA treatment (80 mg/kg, p.o.) significantly increased Na+ excretion rates of non-diabetic and STZ-induced diabetic rats throughout the 5 week experimental period without affecting urine flow, K+ or CI" excretion rates. By comparison with respective control animals, Short-term administrations of OA significantly (p<0.05) increased GFR of non-diabetic (2.88±0.14 vs 3.71±0.30 ml/min) and STZ-diabetic rats (1.81± 0.32 vs 3.07±0.16 ml/min, n=6 in all groups) with concomitant reduction of plasma creatinine concentrations. Acute and Short-term administrations of OA non-diabetic and STZinduced diabetic rats reduced mean arterial blood pressure by comparison with respective control animals. Discussion The results suggest that S. cordatum leaf derived OA not only has the potential to lower blood glucose in diabetes, but also has beneficial effects on kidney function and blood pressure. We suggest that the hypoglycaemic effects of OA mimic those of metformin as evidenced by the fact that neither of these treatments altered plasma insulin concentration of non-diabetic rats. OA-evoked increases in urinary Na+ outputs of STZ-diabetic rats and elevation of GFR suggest up-regulation of renal function by the triterpene. The findings are of considerable importance because they suggest the hypoglycaemic, renal and hypotensive effects of OA in the management of diabetes mellitus. Conclusion The results demonstrated that the oleanolic acid extracted from S. cordatum leaf has blood glucose-lowering effects comparable to standard anti-diabetic drugs in STZ-induced diabetic rats. Furthermore, OA augmented the hypoglycaemic effects of insulin in STZ-induced diabetic rats. These findings suggest that OA may have beneficial effects on some of the processes that are associated with renal derangement in STZ-induced diabetic rats. The results introduce the first in vivo evidence that OA ameliorates kidney function in STZinduced diabetic rats. Keywords: Renal function; diabetes mellitus; triterpenoids; oleanolic acid, hypoglycaemia / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2008.
16

Ex Vivo Evaluation of Myocardial Beta-Adrenergic Receptors in High-Fat Fed STZ and ZDF Models of Diabetes Using [3H]-CGP12177

Haley, James M. 20 December 2013 (has links)
Diabetes mellitus (DM) and hyperglycemia contribute to sympathetic nervous system (SNS) activation and cardiovascular dysfunction. SNS activation and increased norepinephrine levels downregulate cardiac β-adrenergic receptors (β-AR). The ADMIRE-HF trial identified reduced cardiac SNS innervation as an independent prognostic marker in heart failure. The β-AR antagonist [3H]-CGP12177 was used to quantify cardiac β-AR in ex vivo biodistribution studies in streptozotocin (STZ)-treated rats after 8 weeks of sustained hyperglycemia, and in the Zucker Diabetic Fatty (ZDF) rat model of type-2 diabetes at the onset of hyperglycemia (10 weeks of age) and after a sustained period of hyperglycemia (16 weeks of age). In some STZ rats, insulin was provided at the onset of hyperglycemia, or after a sustained period of hyperglycemia. Insulin treatment at both time points prevented reduced [3H]-CGP12177 binding (33-38% compared to controls) observed in STZ hyperglycemics. ZDF β-ARs were intact at 10 weeks but became reduced (16-25% relative to the Zucker leans) following 6 weeks of hyperglycemia. This work supports that cardiac β-AR are reduced in models of DM and that restoring insulin signalling to maintain glycemic control can normalize β-AR density whether provided early or after a period of sustained hyperglycemia.
17

Estudo do processo de reparação òssea após implantação do polietileno poroso em defeitos cirúrgicos no osso parietal de ratas diabéticas tratadas com calcitonina

Claro, Flávio Augusto [UNESP] 27 June 2002 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-06-27Bitstream added on 2014-06-13T20:37:54Z : No. of bitstreams: 1 claro_fa_me_sjc.pdf: 1230472 bytes, checksum: aa7d0bf88466ef0f58ce0587136a08c1 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O propósito deste trabalho foi estudar a reação do tecido ósseo após a implantação de polietileno poroso em defeitos cirúrgicos confeccionados no osso parietal de ratas diabéticas tratadas com calcitonina, mediante análise microscópica. Avaliou-se também a eficiência da aplicação da estreptozotocina na indução do diabete melito em ratos, em dose única de 45mg/Kg, através da utilização de um glicosímetro digital e do exame clínico. Foram utilizadas 27 ratas adultas, divididas em grupo não diabético-controle (C), grupo diabético (D) e grupo diabético tratado com calcitonina (DCa). Os animais do grupo DCa receberam aplicações subcutâneas do hormônio em doses de 16UI/Kg, em dias alternados, desde o pós-operatório imediato até o sacrifício e foram sacrificados após 15, trinta e sessenta dias. Diante dos resultados observados, pode-se concluir que o polietileno poroso foi tolerado pelos tecidos hospedeiros nos animais do grupo C e grupo DCa, provocando reações inflamatórias mais intensas nesse segundo grupo, em todos os períodos de observação. O polietileno poroso não foi tolerado pelos tecidos hospedeiros dos animais do grupo D. Os poros do implante foram preenchidos por um tecido conjuntivo bem vascularizado, conferindo estabilidade ao material no leito receptor, não ocorrendo osteointegração. A calcitonina utilizada nos animais do grupo DCa foi eficaz no tratamento pós-operatório dos animais diabéticos que receberam o polietileno poroso, inibindo o processo de reabsorção e/ou estimulando a neoformação óssea. A estreptozotocina, administrada em dose única de 45 mg/Kg, foi um método eficaz na indução do diabete melito nas ratas, permitindo boas condições de sobrevida. / The purpose of this work was to study the reaction of the bone tissue after the porous polyethylene implantation in confectioned surgical defects in the parietal bone of diabetic rats treated with calcitonin, by means of microscopical analysis. The efficiency of a single dose of streptozotocin, 45mg/Kg, in the induction of diabetes mellitus in rats was also evaluated through the use of a digital glicosimeter and the clinical examination. Twenty-seven adult female rats had been used, divided in not diabetic-control (C), diabetic (D) and diabetic treated with calcitonin (DCa) groups. The animals of group DCa had received subcutaneous applications from the hormone in doses of 16U/Kg, in alternated days, since immediate postoperative until the sacrifice, and all the animals had been sacrificed after 15, 30 and 60 days. Ahead of the results, it can be concluded that the porous polyethylene was tolerated by the host tissue in groups C and DCa, disclosing more intense inflammatory response in group Dca. The pores of the implants had been filled with well vascularizated connective tissue, conferring stability to the material in the receiving site, not occurring osteointegration. Calcitonin used in the animals of group DCa was efficient in the postoperative treatment of the diabetic animals that had received the porous polyethylene implants, inhibiting the bone resorption and/or stimulating the bone formation. Streptozotocin, managed in a single dose of 45 mg/Kg, was an efficient method in the induction of the diabetes mellitus in the rats, allowing good conditions of survival.
18

Avaliação do estresse oxidativo no sangue e na placenta de ratas com diabete de intensidade moderada /

Spada, Ana Paula Machado. January 2009 (has links)
Resumo: Objetivo: avaliar o estresse oxidativo no sangue e na placenta de ratas com diabete de intensidade moderada. Métodos: O diabete foi induzido em ratas Wistar recém-nascidas (grupo diabete moderado) no dia do nascimento (dia 0) por streptozotocin (100 mg/kg, via subcutênea). As ratas do grupo nãodiabético (controle) receberam somente tampão citrato. Na vida adulta, as ratas (diabéticas e controle) foram submetidas ao acasalamento e o dia de diagnóstico positivo de prenhez foi considerado dia 0. A glicemia foi determinada nos dias 0, 7, 14 e 21 de prenhez. No 21º dia de prenhez, as ratas foram anestesiadas e dessangradas para determinação das atividades enzimáticas de superóxido dismutase (SOD), glutationa peroxidase (GSH-Px) e glutationa redutase (GSH-Rd) e das concentrações de grupos tiólicos (SH) e de espécies reativas ao ácido tiobarbitúrico (TBARS). Em seguida, as placentas foram retiradas e processadas para determinação das atividades de SOD e catalase e concentração de TBARS, gluationa reduzida e grupos tiólicos. Resultados: Ratas com diabete induzido no período neonatal (grupo diabético) apresentaram glicemia superior a 120mg/dl no dia 0 de prenhez e foi observada hiperglicemia no 14º dia de prenhez. A análise do estresse oxidativo em hemáceas lavadas mostrou que no grupo diabético houve aumento significativo na atividade da GSH-Px. No tecido placentário a atividade da catalase foi significativamente maior em ratas com diabete moderado. Conclusão: Frente às condições experimentais analisadas, o aumento dos biomarcadores do sistema antioxidante em ratas com diabete de intensidade moderada foram suficientes para conter o estresse oxidativo. / Abstract: Objective: To evaluate the oxidative stress in blood sample and placental of female rats that received streptozotocin in the neonatal period. Methods: The diabetes was induced in female offspring (diabetic group) in the day of the birth (day 0) for streptozotocin (100 mg/kg, subcutaneous route). Female control rat (control group) received only citrate buffer. In the adult life, the female rats were submitted to the mating and the day the positive diagnosis, was considered day 0 of pregnancy. The glycemia was measured in the 0, 7, 14 and 21 of pregnancy. At day 21 of pregnancy, the female rats were anesthetized and died by decapitation for collection of the blood for determination of the enzymatic activity of the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) and of the concentrations of thiols group and thiobarbituric acid reactive substances (TBARS). Afterwards, placental were removed and processed for determinations of the enzymatic activity of the SOD and catalase and of the concentrations of the TBARS, glutathione reduced (GSH) and thiols group (SH). Results: Diabetic rats presented blood glucose concentration greater than 120 mg/dL in the day 0 of pregnancy and hyperglycemia in 14 º day of pregnancy. The analysis of the oxidative stress in maternal blood sample showed increased in GSH-Px activity. In placental tissue catalase activity of diabetic group is found to be increase in homogenate tissue in diabetic group. Conclusion: The hyperglycemia in diabetic rats increased antioxidant system biomarkers, however, these alterations were enough to control oxidative stress. / Orientador: Débora Cristina Damasceno / Coorientador: Tiago Rodrigues / Mestre
19

Diabetes gestacional: relação entre estresse oxidativo e a expressão do fator nuclear Kappa B

SANTOS, Geórgia Maria Ricardo Félix dos 15 August 2013 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-06-30T12:19:46Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Georgia Maria Ricardo Felix dos Santos_Mestrado.pdf: 1018948 bytes, checksum: eaff2e3a96759aec9a4685114c9635cb (MD5) / Made available in DSpace on 2016-06-30T12:19:46Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Georgia Maria Ricardo Felix dos Santos_Mestrado.pdf: 1018948 bytes, checksum: eaff2e3a96759aec9a4685114c9635cb (MD5) Previous issue date: 2013-08-15 / CAPEs / Elevados níveis de hiperglicemia durante a gestação pode ter consequências deletérias para prole que inclui doenças cardiovasculares (DCV) e renais. As complicações cardiovasculares do diabetes resultam de um conjunto de fatores que envolvem a hiperglicemia crônica, a formação excessiva dos produtos finais de glicação avançada (AGEs) e de oxidação proteica (AOPP) e a ativação do fator de transcrição nuclear kappaB (NF-κB), associada à liberação de citocinas pró-inflamatórias. Portanto, é de grande relevância a elucidação de mecanismos envolvidos na gênese e/ou manutenção do processo oxidativo que pode ser perpetuada na prole exposta à hiperglicemia. O objetivo deste estudo foi investigar os efeitos da exposição intra-uterina a hiperglicemia (> 200 mg/dL) sobre AGEs, AOPP, bem como a expressão proteica do NF-κB, a expressão gênica da interleucina-1 beta (IL-1ß) e Nox 4 (homólogo da subunidade da NADPH oxidase) na prole adulta. Para isto, o DG foi induzido no sétimo dia de gestação com dose única de estreptozotocina (STZ, 42mg/kg, i.p.) dissolvida em tampão citrato (veículo). Fêmeas controles receberam apenas veículo. A prole foi dividida em dois grupos de acordo com o tratamento da mãe: controle não diabético (ND) e diabetes gestacional (DG). Na idade adulta, foram realizadas as dosagens de glicose, triglicerídeos, colesterol total e HDL. A concentração plasmática de AGEs foi determinada por fluorescência e a de AOPP por espectrofotometria, os níveis de peroxidação lipídica pelas substâncias reativas ao ácido tiobarbitúrico (TBARS). A expressão proteica do NF-κB foi analisada em aortas através de Western Blot. Foi utilizada reação em cadeia de polimerase quantitativa em tempo real (RTq-PCR) para avaliar a expressão gênica da IL-1ß e Nox 4. Os níveis de glicose, triglicerídeos, colesterol total foram significativamente (p < 0,05) maiores na prole DG quando comparadas a prole ND. A prole DG apresentaram níveis elevados de AGEs (p < 0,01), AOPP (p < 0,05) e TBARS (p < 0,05). Em aorta, a expressão proteica do NF-κB foi mais elevada (p < 0,05) no grupo DG do que no ND. Adicionalmente, foi observado um aumento da expressão gênica da IL-1ß e da Nox4. O número de néfrons desses animais foi significativamente reduzido (p < 0,001). A associação de níveis elevados de estresse oxidativo e interleucina-1 beta podem ser responsáveis pela estimulação da expressão proteica do NF-κB. Juntas, essas alterações em um ambiente hiperglicêmico, com indícios de comprometimento renal, poderiam desencadear alterações vasculares. / Experimental evidences support the hypothesis that diseases can be programmed during the period intrauterine. This concept of programming fetal has been used as basis for knowledge of some chronic diseases, such the cardiovascular. Cardiovascular disease has been associated with hyperglycemia, increased level of advanced glycation end products (AGE) and of advanced oxidation products (AOPP) activate the transcription factor nuclear factor-kappaB (NF-κB) associated with inflammatory cytokine liberation. Therefore, the present study was designed to examine the alterations produced by maternal diabetes over the AGEs, AOPP, NF-κB protein expression, and mRNA expressions of IL-1β and Nox4 in adult offspring rats. Maternal diabetes was induced in female Wistar rats with a single dose of streptozotocin (STZ; 42 mg/kg, i.p.) on the 7th day of pregnancy. Control animals only received STZ vehicle. The offspring were divided into two groups: control non-diabetic (ND) and gestational diabetes (DG). Plasma levels of glucose, total cholesterol, HDL cholesterol and triglycerides were analyzed through biochemical measurements. Plasma levels of AGEs and AOPPs were detected using spectrofluorimetry and spectrophotometry, respectively. Lipid peroxidation was assessed in liver tissue by measuring thiobarbituric acid reactive substances (TBARS). The NF-κB protein expression was evaluated by Western blot. The mRNA levels of IL-1β and Nox4 were detected quantitatively by real time polymerase chain reaction (real-time PCR). In the DG offspring, it was observed that plasma levels of glucose, total cholesterol, HDL cholesterol and triglycerides were higher when compared to the control group. AGEs, AOPP and TBARS concentration were significantly higher in animals exposed to the DG compared with ND. The NF-κB protein expression was higher (p < 0,05) in aorta from DG than in ND. In addition, the expression of IL-1β and Nox4 mRNA was elevated. The number of nephron in DG was significantly reduced (p < 0,001). These results also support the involvement of oxidative stress species in IL-1β induced NF-κB expression. Together, these data suggest that hyperglycemia is a risk factor for vascular alterations.
20

Ex Vivo Evaluation of Myocardial Beta-Adrenergic Receptors in High-Fat Fed STZ and ZDF Models of Diabetes Using [3H]-CGP12177

Haley, James M. January 2014 (has links)
Diabetes mellitus (DM) and hyperglycemia contribute to sympathetic nervous system (SNS) activation and cardiovascular dysfunction. SNS activation and increased norepinephrine levels downregulate cardiac β-adrenergic receptors (β-AR). The ADMIRE-HF trial identified reduced cardiac SNS innervation as an independent prognostic marker in heart failure. The β-AR antagonist [3H]-CGP12177 was used to quantify cardiac β-AR in ex vivo biodistribution studies in streptozotocin (STZ)-treated rats after 8 weeks of sustained hyperglycemia, and in the Zucker Diabetic Fatty (ZDF) rat model of type-2 diabetes at the onset of hyperglycemia (10 weeks of age) and after a sustained period of hyperglycemia (16 weeks of age). In some STZ rats, insulin was provided at the onset of hyperglycemia, or after a sustained period of hyperglycemia. Insulin treatment at both time points prevented reduced [3H]-CGP12177 binding (33-38% compared to controls) observed in STZ hyperglycemics. ZDF β-ARs were intact at 10 weeks but became reduced (16-25% relative to the Zucker leans) following 6 weeks of hyperglycemia. This work supports that cardiac β-AR are reduced in models of DM and that restoring insulin signalling to maintain glycemic control can normalize β-AR density whether provided early or after a period of sustained hyperglycemia.

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