Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 149-160).

The role of cholesterol-rich diet and of high protein supplement on the development of a glomerular lesion was studied in male guinea pigs. The possible pathogenesis of lipid-induced glomerulosclerosis was investigated. Four experiments were carried out. Four groups of guinea pigs were used in experiment I: CONT group was kept on normal guinea pig chow for 70 days; HC group was kept on 2% cholesterol diet for 70 days; HP group was kept on 50% casein diet for 70 days, and HCHP group received 2% cholesterol diet for 30 days and 2% cholesterol/50% casein diet for another 40 days. In experiment II two groups were used: CONT group and acetyl phenylhydrazine (APH)-treated group in which haemolytic anaemia was induced. In the third experiment the same dietary regimens as described in experiment I were used. In experiment IV three groups, namely CONT, HC, and HCHP, were employed. The animals in experiment IV were sacrificed after 5, 10, and 30 days. The first experiment explored the role of high cholesterol - and high cholesterol/high protein diet in the development of glomerulosclerosis. The other three experiments were designed to learn about the possible mechanism of lipid-induced glomerulosclerosis. Lipid analyses of plasma, erythrocytes and kidney tissue as well as complete blood count, erythrocyte osmotic fragility and blood cell morphology studies were performed. Kidney histology, histochemistry, immunohistochemistry, electron microscopy, morphometry, and renal and liver function tests were also carried out. De novo cholesterol synthesis was assessed by measuring HMG COA reductase activity and incorporation of tritiated water into cholesterol in the kidneys. Cholesterol-fed animals showed decreased weight gain, increased cholesterol concentration in plasma, erythrocytes, and kidney tissue. Haemolytic anaemia was documented after 70 days on this dietary regimen. Glomerular proliferation lesion was first noted at day 30 and progressed by day 70. Moderate proteinuria and haematuria were observed at day 70. Addition of protein to the high cholesterol diet led to a further decrease in weight gain. It also increased the mortality rate to 40% by day 70. The glomerular lesion, proteinuria and haematuria, and possibly haemolysis were more marked in the HCHP group. No causal relationship was found between liver function, immune complexes, haemolysis and glomerulosclerosis. Serum phosphate levels did not differ among the groups. The lipid found in the kidney of both HC and HCHP groups was mostly of plasma origin, since the kidney cholesterol de novo synthesis was suppressed in these two groups compared to the CONT group. There was a concommitant increase in the lipid content of kidney tissue and the mesangial expansion (MA/GTA) at day 30. No significant increase in the intraglomerular monocyte/macrophage was found at day 30 in the HCHP group compared to the HC group. However, a significant correlation (r=0.678, p 0.001) was found between the number of these cells and MA/GTA ratio among the four experimental groups at day 70. These data indicate that lipid deposits in kidney tissue may induce a glomerulosclerotic lesion in the absence of monocytes. However, these cells likely augment the proliferation of mesangial cells. We postulate that high protein diet could worsen the lipid-induced glomerular lesion by increasing delivery of abnormal lipoproteins to the kidney which could trigger mesangial cellular proliferation directly and indirectly by a macrophage-mediated process. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Yang, Nan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (p. 94-117). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.I / ABSTRACT --- p.II / LIST OF ABBREVIATIONS --- p.VII / TABLE OF CONTENTS --- p.IX / Chapter Chapter 1 --- general introduction / Chapter 1.1 --- Cholesterol and cardiovascular disease --- p.1 / Chapter 1.2 --- Functions of cholesterol and lipoprotein --- p.2 / Chapter 1.3 --- Cholesterol metabolism and regulation in the body --- p.5 / Chapter 1.3.1 --- General process of cholesterol metabolism --- p.5 / Chapter 1.3.2 --- Cholesterol metabolism in liver --- p.6 / Chapter 1.3.2.1 --- The uptake of LDL cholesterol into the liver --- p.6 / Chapter 1.3.2.2 --- Cholesterol synthesis --- p.7 / Chapter 1.3.2.3 --- Synthesis of bile acids --- p.8 / Chapter 1.3.2.4 --- RCT pathway --- p.9 / Chapter 1.3.3 --- Lipids absorption in the intestine lumen --- p.9 / Chapter 1.3.3.1 --- Niemann-Pick Cl like 1(NPC1L1) --- p.10 / Chapter 1.3.3.2 --- ABCG5/8 --- p.10 / Chapter 1.3.3.3 --- Acyl-CoA:cholesterol acyltransferase (ACAT) 2 --- p.11 / Chapter 1.3.4 --- Cholesterol homeostasis --- p.11 / Chapter 1.3.5 --- The regulation of the cholesterol metabolism --- p.11 / Chapter 1.3.5.1 --- The role of SREBP-2 --- p.11 / Chapter 1.3.5.2 --- The role of LXR --- p.13 / Chapter 1.3.5.3 --- Feedback regulation of cholesterol --- p.13 / Chapter 1.4 --- Bile acid metabolism --- p.13 / Chapter 1.4.1 --- The function of bile acid --- p.13 / Chapter 1.4.2 --- Bile acid synthesis --- p.14 / Chapter 1.4.3 --- Enterohepatic circulation of bile --- p.14 / Chapter 1.5 --- Effect of Dietary composition on the blood cholesterol --- p.15 / Chapter 1.5.1 --- Dietary cholesterol --- p.15 / Chapter 1.5.2 --- Dietary protein --- p.15 / Chapter 1.5.2.1 --- Research history of dietary protein on the cholesterol --- p.15 / Chapter 1.5.2.2 --- Dietary casein --- p.17 / Chapter 1.5.2.3 --- Soy protein --- p.18 / Chapter 1.5.2.4 --- Buckwheat protein --- p.18 / Chapter 1.5.2.5 --- Mechanism of dietary protein on the cholesterol --- p.18 / Chapter 1.5.3 --- Dietary fiber --- p.18 / Chapter 1.5.4 --- Other functional components in the diet --- p.19 / Chapter 1.5.4.1 --- Phytosterol --- p.19 / Chapter 1.5.4.2 --- Dietary flavonoids --- p.21 / Chapter 1.6 --- Chemical composition of Tartary buckwheat --- p.22 / Chapter 1.6.1 --- Buckwheat protein --- p.22 / Chapter 1.6.2 --- Dietary fiber --- p.23 / Chapter 1.6.3 --- Phytosterols --- p.23 / Chapter 1.6.4 --- Flavonoids --- p.23 / Chapter Chapter 2 --- Effect of Tartary Buckwheat Flour on Blood Cholesterol Level in Male Hamsters / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Objective --- p.27 / Chapter 2.3 --- Materials and methods --- p.27 / Chapter 2.3.1 --- Hamsters --- p.27 / Chapter 2.3.2 --- Diets --- p.28 / Chapter 2.3.3 --- "Determination of plasma lipid, lipoproteins" --- p.30 / Chapter 2.3.4 --- Determination of cholesterol concentration in organs --- p.31 / Chapter 2.3.5 --- Determination of fecal neutral and acidic sterols output --- p.31 / Chapter 2.3.6 --- "Western blotting of liver SREBP-2, LDLR, HMGR, LXR and CYP7A1 proteins" --- p.36 / Chapter 2.3.7 --- "Real-Time PCR Analysis of mRNA or Liver SREBP-2, LDLR, HMGR, and CYP7A1 and Small Intestine NPC1L1, ABCG5, ABCG8, ACAT2, and MTP" --- p.37 / Chapter 2.3.8 --- Intestinal ACAT2 activity measurement --- p.37 / Chapter 2.3.9 --- Statistics --- p.39 / Chapter 2.4 --- Results --- p.40 / Chapter 2.4.1 --- Nutritional composition of different flours --- p.40 / Chapter 2.4.2 --- "Growth, food intake and relative organ weights" --- p.44 / Chapter 2.4.3 --- Effect of different flour diets on the plasma lipid profile --- p.44 / Chapter 2.4.4 --- Effect of different flour diets on organ cholesterol of hamsters --- p.44 / Chapter 2.4.5 --- Cholesterol balance and excretion of fecal neutral and acidic Sterols --- p.44 / Chapter 2.4.6 --- "Effect of different flour diets on hepatic SREBP-2, HMGR, LDLR and CYP7A1 immunoreactive mass" --- p.51 / Chapter 2.4.7 --- "Effect of different flour diets on intestinal ABCG5, ABCG8, NPC1L1, MTP, and ACAT2 immunoreactive mass" --- p.54 / Chapter 2.4.8 --- Effect of different diet group on intestinal ACAT activity --- p.54 / Chapter 2.5 --- Discussion --- p.57 / Chapter 2.6 --- Summary --- p.61 / Chapter Chapter 3 --- Effect of DefattedTartary Buckwheat Protein Extract on Blood Cholesterol Level in Male Hamsters / Chapter 3.1 --- Introduction --- p.62 / Chapter 3.2 --- Objective --- p.63 / Chapter 3.3 --- Materials and methods --- p.63 / Chapter 3.3.1 --- Hamsters --- p.63 / Chapter 3.3.2 --- Diets --- p.63 / Chapter 3.3.3 --- "Determination of plasma lipid, lipoproteins" --- p.66 / Chapter 3.3.4 --- Determination of cholesterol concentration in organs and fecal neutral and acidic sterols output --- p.66 / Chapter 3.3.5 --- "Western blotting of liver SREBP-2, LDLR, HMGR and CYP7A1 proteins" --- p.66 / Chapter 3.3.6 --- "Real-Time PCR Analysis of mRNA or Liver SREBP-2, LDLR, HMGR, and CYP7A1 and Small Intestine NPC1L1, ABCG5, ABCG8, ACAT2, and MTP" --- p.66 / Chapter 3.3.7 --- Intestinal ACAT2 activity measurement --- p.67 / Chapter 3.3.8 --- Protein digestibility determination --- p.67 / Chapter 3.3.9 --- Statistics --- p.67 / Chapter 3.4 --- Results --- p.68 / Chapter 3.4.1 --- Diet composition --- p.68 / Chapter 3.4.2 --- "Growth, food intake, fecal excretion" --- p.72 / Chapter 3.4.3 --- Relative organ weights and organ cholesterol concentration --- p.72 / Chapter 3.4.4 --- Effect of different defatted protein extracts on the plasma lipid profile --- p.76 / Chapter 3.4.5 --- Cholesterol Balance and Excretion of Fecal Neutral and Acidic Sterols --- p.76 / Chapter 3.4.6 --- "Apparent protein digestibility in casein, TBP, WP and RP diet groups" --- p.77 / Chapter 3.4.7 --- "Effect of different defatted protein extracts on hepatic SREBP-2, HMGR, LDLR and CYP7A1 immunoreactive mass" --- p.83 / Chapter 3.4.8 --- "Effect of different defatted protein extracts on intestinal ABCG5, ABCG8, NPC1L1, MTP, and ACAT2 immunoreactive mass" --- p.83 / Chapter 3.5 --- Discussion --- p.87 / Chapter 3.6 --- Summary --- p.91 / Chapter Chapter 4 --- Conclusion --- p.92 / References --- p.94

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Chiu Chi Pang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 121-134). / Abstracts in English and Chinese. / DECLARATION --- p.i / ACKNOWLEDGEMENTS --- p.ii / ABBREVIATIONS --- p.iii / ABSTRACT --- p.vi / 摘要 --- p.viii / Chapter CHAPTER 1: --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1 --- Cholesterol --- p.1 / Chapter 1.1.1 --- History of cholesterol --- p.1 / Chapter 1.1.2 --- Structure of cholesterol --- p.1 / Chapter 1.1.3 --- Biological function of cholesterol --- p.3 / Chapter 1.1.4 --- Sources of cholesterol in our body --- p.3 / Chapter 1.2 --- Lipid hypothesis --- p.4 / Chapter 1.2.1 --- Relationship between dietary cholesterol and plasma cholesterol --- p.4 / Chapter 1.2.2 --- "Hypercholesterolemia , atherosclerosis and coronary heart disease (CHD)" --- p.4 / Chapter 1.2.3 --- Individual variation --- p.5 / Chapter 1.3 --- Cholesterol homeostasis --- p.7 / Chapter 1.3.1 --- SREBPs up-regulates the expression of LDL-receptor and HMG-CoA reductase --- p.7 / Chapter 1.3.2 --- HMG-CoA reductase as the rate-limiting enzyme in cholesterol synthesis --- p.11 / Chapter 1.3.3 --- LDL-receptor as the major protein removing plasma cholesterol …… --- p.12 / Chapter 1.3.4 --- LXR-α as an activator of CYP7A1 --- p.14 / Chapter 1.3.5 --- CYP7A1 controls the classical pathway for the elimination of hepatic cholesterol --- p.16 / Chapter 1.3.6 --- Bile acids as the metabolites of CYP7A1 --- p.17 / Chapter 1.4 --- Previous works in our laboratory --- p.20 / Chapter 1.5 --- Objective of this project --- p.22 / Chapter CHAPTER 2: --- INCREASED EXPRESSION OF LDL-RECEPTOR IS RESPONSIBLE FOR THE HYPO-RESPONSIVENESS OF RATS TO DIETARY CHOLESTEROL --- p.23 / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Objective --- p.24 / Chapter 2.3 --- Methods and materials --- p.25 / Chapter 2.3.1 --- Animals --- p.25 / Chapter 2.3.2 --- Diets --- p.25 / Chapter 2.3.3 --- Determination of serum cholesterol --- p.26 / Chapter 2.3.4 --- Western blot --- p.26 / Chapter 2.3.5 --- Probe production for LDL-receptor --- p.27 / Chapter 2.3.5.1 --- Extraction of total RNA --- p.27 / Chapter 2.3.5.2 --- Reverse-transcription reaction of total RNA --- p.28 / Chapter 2.3.5.3 --- Polymerase chain reaction (PCR) of LDL- receptor fragment from cDNA template --- p.28 / Chapter 2.3.5.4 --- Separation and purification of PCR products --- p.29 / Chapter 2.3.5.5 --- Polishing of purified PCR products --- p.29 / Chapter 2.3.5.6 --- Ligation of PCR products and pPCR-script Amp SK(+) cloning vector --- p.30 / Chapter 2.3.5.7 --- Transformation --- p.30 / Chapter 2.3.5.8 --- Preparing glycerol stocks containing the bacterial clones --- p.31 / Chapter 2.3.5.9 --- Plasmid DNA preparation --- p.31 / Chapter 2.3.5.10 --- Clones confirmation by restriction enzyme digestion --- p.32 / Chapter 2.3.5.11 --- Clones confirmation by automatic sequencing --- p.32 / Chapter 2.3.5.12 --- Linearization of the plasmid DNA --- p.33 / Chapter 2.3.5.13 --- DIG-labeling of RNA probe --- p.35 / Chapter 2.3.5.14 --- Testing of DIG-labeled probe --- p.35 / Chapter 2.3.6 --- Probe production for HMG-CoA reductase --- p.36 / Chapter 2.3.7 --- Probe production for GAPDH --- p.37 / Chapter 2.3.8 --- Northern blot --- p.38 / Chapter 2.3.9 --- Determination of hepatic cholesterol --- p.39 / Chapter 2.3.10 --- Statistics --- p.40 / Chapter 2.4 --- Results --- p.42 / Chapter 2.4.1 --- Growth and food intake --- p.42 / Chapter 2.4.2 --- Effect of cholesterol supplements on serum cholesterol --- p.42 / Chapter 2.4.3 --- Effect of cholesterol supplements on liver cholesterol content --- p.45 / Chapter 2.4.4 --- "Stimulatory effect of high cholesterol diet on nSREBP-2, LDL-receptor and HMG-CoA reductase in rats" --- p.45 / Chapter 2.4.5 --- "Effect of high cholesterol diet on nSREBP-2, LDL-receptor and HMG-CoA reductase in hamsters" --- p.49 / Chapter 2.4.6 --- The regulation of LDL-receptor and HMG-CoA reductase existed at transcriptional level --- p.54 / Chapter 2.5 --- Discussion --- p.59 / Chapter CHAPTER 3: --- RATS ARE HYPO-RESPONSIVE TO DIETARY CHOLESTEROL DUE TO EFFICIENT ELIMINATION OF CHOLESTEROL --- p.67 / Chapter 3.1 --- Introduction --- p.67 / Chapter 3.2 --- Objective --- p.69 / Chapter 3.3 --- Methods and materials --- p.70 / Chapter 3.3.1 --- Animals and diets --- p.70 / Chapter 3.3.2 --- Western blot --- p.70 / Chapter 3.3.3 --- Probe production for CYP7A1 and LXR-α --- p.71 / Chapter 3.3.4 --- Northern blot --- p.71 / Chapter 3.3.5 --- Determination of fecal neutral and acidic sterols --- p.71 / Chapter 3.3.5.1 --- Separation of neutral and acidic sterols --- p.71 / Chapter 3.3.5.2 --- Neutral sterols analysis --- p.72 / Chapter 3.3.5.3 --- Acidic sterols analysis --- p.72 / Chapter 3.3.5.4 --- GLC analysis of neutral and acidic sterols --- p.73 / Chapter 3.3.6 --- Statistics --- p.73 / Chapter 3.4 --- Results --- p.76 / Chapter 3.4.1 --- Effect of cholesterol supplements on fecal total neutral sterols --- p.76 / Chapter 3.4.2 --- Effect of cholesterol supplements on fecal total bile acids --- p.76 / Chapter 3.4.3 --- CYP7A1 protein on rats showed a concentration-dependent increase with response to dietary cholesterol while hamsters did not --- p.79 / Chapter 3.4.4 --- The regulation of CYP7A1 was at transcriptional level --- p.79 / Chapter 3.4.5 --- LXR-α demonstrated a parallel changes in its expression at both translational and transcriptional level --- p.84 / Chapter 3.5 --- Discussion --- p.88 / Chapter CHAPTER 4: --- MECHANISM FOR INDIVIDUAL VARIATION OF SERUM CHOLESTEROL LEVEL IN RATS AND HAMSTERS FED A HIGH CHOLESTEROL DIET --- p.94 / Chapter 4.1 --- Introduction --- p.94 / Chapter 4.2 --- Objective --- p.96 / Chapter 4.3 --- Methods and materials --- p.97 / Chapter 4.3.1 --- Diet and animals --- p.97 / Chapter 4.3.2 --- Western blot --- p.97 / Chapter 4.3.3 --- Statistics --- p.97 / Chapter 4.4 --- Results --- p.99 / Chapter 4.4.1 --- Growth and food intake --- p.99 / Chapter 4.4.2 --- Change of serum cholesterol --- p.99 / Chapter 4.4.3 --- Correlation between various protein expression and serum cholesterol --- p.99 / Chapter 4.4.3.1 --- Correlation between LDL-receptor and serum total cholesterol in rats --- p.99 / Chapter 4.4.3.2 --- Correlation between CYP7A1 and serum total cholesterolin rats --- p.99 / Chapter 4.4.3.3 --- Correlation between nSREBP-2 and serum total cholesterolin rats --- p.105 / Chapter 4.4.3.4 --- Correlation between LXR-a and serum total cholesterol in rats --- p.105 / Chapter 4.4.3.5 --- Correlation between HMG-CoA reductase and serum total cholesterol in rats --- p.105 / Chapter 4.4.3.6 --- Correlation between LDL-receptor and serum total cholesterol in hamsters --- p.105 / Chapter 4.4.3.7 --- Correlation between CYP7A1 and serum total cholesterolin hamsters --- p.109 / Chapter 4.4.3.8 --- Correlation between nSREBP-2 and serum total cholesterolin hamsters --- p.109 / Chapter 4.4.3.9 --- Correlation between HMG-CoA reductase and serum total cholesterol in hamsters --- p.109 / Chapter 4.5 --- Discussion --- p.114 / Chapter CHAPTER 5: --- CONCLUSION --- p.117 / REFERENCES --- p.121

Introdução: A bexiga é responsável em armazenar urina em volume adequado e de esvaziar seu conteúdo de forma plena. Suas propriedades miogênicas intrínsecas e viscoelásticas são as responsáveis por esta função. Disfunções vesicais podem ser decorrentes, dentre outras causas, de anormalidades intrínsecas da musculatura detrusora ou da composição de sua matriz extracelular (MEC). O colágeno corresponde a 50% do estroma vesical, possuindo importante papel na adaptação vesical a condições fisiopatológicas específicas. Os colágenos tipo I e III são os mais comuns, sendo o colágeno tipo III o primeiro a ser sintetizado em processos de reparação e fibrose. Diversas afecções como a obstrução infravesical (OIV) parcial crônica podem induzir estes processos através da remodelação da MEC e conseqüentemente alterar a função vesical. Acredita-se que a hipercolesterolemia também o faça, porém ainda não foi reproduzida tal associação a nível morfológico. O objetivo deste estudo é avaliar se dieta hipercolesterolêmica promove alterações estruturais vesicais em ratos, especialmente no que diz respeito à remodelação colágena. Método: Foram utilizadas 45 ratas da raça Wistar, de quatro semanas de idade, divididas em três grupos: 1) controle com dieta comum padrão para roedores (DN); 2) modelo de OIV com DN e 3) controle com dieta de alto teor lipídico (DATL 1,25% colesterol). Análise sérica do colesterol e fração LDL e medição do peso corporal foram realizadas em todos os animais inicialmente e no final do estudo. Com quatro semanas de estudo, as ratas dos grupos 1 e 3 foram submetidas à cirurgia simulada, enquanto os animais do grupo 2 foram efetivamente submetidos à cirurgia de OIV parcial. Após dissecção da uretra, fez-se uma ligadura parcial com Nylon 5-0, com um lúmen residual de aproximadamente 1 mm. Após seis semanas, todos os animais foram submetidos à remoção de suas bexigas e então sacrificados. Análise morfológica foi realizada através da coloração de Picrosirius vermelho e de imuno-histoquímica para os colágenos tipos I e III. As variáveis categóricas fora expressas em médias ± desvio padrão e a comparação entre grupos realizada pelo método ONEWAY-ANOVA e pela análise de comparações múltiplas de Tukey, quando houve diferença. A significância estatística foi definida como p < 0,05. Resultados: Este estudo demonstrou que a DATL em ratas Wistar proporcionou aumento significativo das taxas de LDL-colesterol (p < 0,001) e do peso corporal (p = 0,017) em relação a ratas alimentadas com DN no período de dez semanas. Além disto, induziu alterações morfológicas significativas da matriz extracelular, no que diz respeito à remodelação das fibras colágenas imaturas e do colágeno tipo III em relação ao grupo controle (p = 0,002 e p = 0,016, respectivamente), de forma semelhante ao que ocorre no modelo experimental de OIV parcial crônica. Conclusão: A dieta hipercolesterolêmica administrada a ratas Wistar promoveu, além de aumento do peso corporal e elevação da fração LDL-colesterol, alterações significativas na composição colágena da MEC vesical. / Purpose: Preserved bladder function is defined as the adequate storage and emptying of its urinary content. Compliance is an important factor for these functions and is directly related to the extracellular matrix composition. Its abnormalities can lead to bladder dysfunctions. The collagen represents 50% of bladder stroma, playing an important role in the bladder adaptation to specific pathologic conditions. Types I and III collagens are the most prevalent in bladder wall whereas type III collagen is the first synthesized in reparation and fibrosis processes. Bladder outlet obstruction (BOO) promotes this process and hypercholesterolemia is also believed to create conditions for it, although no morphologic association has already been demonstrated. In this study we aimed to verify if hypercholesterolemic diet promotes structural bladder wall modifications, regarding the collagen remodeling. Methods: Forty-five female heterogenic Wistar 4 weeks-old rats were divided into three groups: 1) control fed on a normal diet (ND); 2) BOO model fed on a ND and 3) control fed on a hypercholesterolemic diet (HCD 1.25% cholesterol). Initially, serum cholesterol, LDL-cholesterol and body weight were measured. Four weeks later groups 1 and 3 underwent a sham operation while group 2 underwent a partial BOO operation. After the urethra was dissected a 5-zero nylon suture was passed and tied loosely around the urethra with a 22G needle besides it. Six weeks later the bladders of all animals were removed, serum cholesterol and LDL-cholesterol analysis was performed, body weight was measured and then they were sacrificed. Morphological analysis was performed by Picrosirius red staining and immunohistochemistry for types I and III collagen. Statistical analysis was done comparing groups by the Oneway-Anova method and Tukey multiple comparisons when needed. Significance was considered when p < 0.05. Results: Wistar rats fed on a HC diet had a significant increase of LDL-cholesterol levels (p < 0.001) and body weight (p = 0.017), when compared to the control group fed on a normal diet in the period of ten weeks. Moreover, HC diet induced significant morphological alterations of the extracellular matrix of the bladder wall, regarding immature collagen fibers and type III collagen remodeling, when compared to the control group (p = 0.002 and p = 0.016, respectively), resembling the process promoted in the BOO model. Conclusions: A hypercholesterolemic diet in Wistar rats promoted, besides the body weight and LDL-cholesterol increase, morphological alterations of the bladder extracellular matrix, regarding collagen remodeling.

Introdução: A bexiga é responsável em armazenar urina em volume adequado e de esvaziar seu conteúdo de forma plena. Suas propriedades miogênicas intrínsecas e viscoelásticas são as responsáveis por esta função. Disfunções vesicais podem ser decorrentes, dentre outras causas, de anormalidades intrínsecas da musculatura detrusora ou da composição de sua matriz extracelular (MEC). O colágeno corresponde a 50% do estroma vesical, possuindo importante papel na adaptação vesical a condições fisiopatológicas específicas. Os colágenos tipo I e III são os mais comuns, sendo o colágeno tipo III o primeiro a ser sintetizado em processos de reparação e fibrose. Diversas afecções como a obstrução infravesical (OIV) parcial crônica podem induzir estes processos através da remodelação da MEC e conseqüentemente alterar a função vesical. Acredita-se que a hipercolesterolemia também o faça, porém ainda não foi reproduzida tal associação a nível morfológico. O objetivo deste estudo é avaliar se dieta hipercolesterolêmica promove alterações estruturais vesicais em ratos, especialmente no que diz respeito à remodelação colágena. Método: Foram utilizadas 45 ratas da raça Wistar, de quatro semanas de idade, divididas em três grupos: 1) controle com dieta comum padrão para roedores (DN); 2) modelo de OIV com DN e 3) controle com dieta de alto teor lipídico (DATL 1,25% colesterol). Análise sérica do colesterol e fração LDL e medição do peso corporal foram realizadas em todos os animais inicialmente e no final do estudo. Com quatro semanas de estudo, as ratas dos grupos 1 e 3 foram submetidas à cirurgia simulada, enquanto os animais do grupo 2 foram efetivamente submetidos à cirurgia de OIV parcial. Após dissecção da uretra, fez-se uma ligadura parcial com Nylon 5-0, com um lúmen residual de aproximadamente 1 mm. Após seis semanas, todos os animais foram submetidos à remoção de suas bexigas e então sacrificados. Análise morfológica foi realizada através da coloração de Picrosirius vermelho e de imuno-histoquímica para os colágenos tipos I e III. As variáveis categóricas fora expressas em médias ± desvio padrão e a comparação entre grupos realizada pelo método ONEWAY-ANOVA e pela análise de comparações múltiplas de Tukey, quando houve diferença. A significância estatística foi definida como p < 0,05. Resultados: Este estudo demonstrou que a DATL em ratas Wistar proporcionou aumento significativo das taxas de LDL-colesterol (p < 0,001) e do peso corporal (p = 0,017) em relação a ratas alimentadas com DN no período de dez semanas. Além disto, induziu alterações morfológicas significativas da matriz extracelular, no que diz respeito à remodelação das fibras colágenas imaturas e do colágeno tipo III em relação ao grupo controle (p = 0,002 e p = 0,016, respectivamente), de forma semelhante ao que ocorre no modelo experimental de OIV parcial crônica. Conclusão: A dieta hipercolesterolêmica administrada a ratas Wistar promoveu, além de aumento do peso corporal e elevação da fração LDL-colesterol, alterações significativas na composição colágena da MEC vesical. / Purpose: Preserved bladder function is defined as the adequate storage and emptying of its urinary content. Compliance is an important factor for these functions and is directly related to the extracellular matrix composition. Its abnormalities can lead to bladder dysfunctions. The collagen represents 50% of bladder stroma, playing an important role in the bladder adaptation to specific pathologic conditions. Types I and III collagens are the most prevalent in bladder wall whereas type III collagen is the first synthesized in reparation and fibrosis processes. Bladder outlet obstruction (BOO) promotes this process and hypercholesterolemia is also believed to create conditions for it, although no morphologic association has already been demonstrated. In this study we aimed to verify if hypercholesterolemic diet promotes structural bladder wall modifications, regarding the collagen remodeling. Methods: Forty-five female heterogenic Wistar 4 weeks-old rats were divided into three groups: 1) control fed on a normal diet (ND); 2) BOO model fed on a ND and 3) control fed on a hypercholesterolemic diet (HCD 1.25% cholesterol). Initially, serum cholesterol, LDL-cholesterol and body weight were measured. Four weeks later groups 1 and 3 underwent a sham operation while group 2 underwent a partial BOO operation. After the urethra was dissected a 5-zero nylon suture was passed and tied loosely around the urethra with a 22G needle besides it. Six weeks later the bladders of all animals were removed, serum cholesterol and LDL-cholesterol analysis was performed, body weight was measured and then they were sacrificed. Morphological analysis was performed by Picrosirius red staining and immunohistochemistry for types I and III collagen. Statistical analysis was done comparing groups by the Oneway-Anova method and Tukey multiple comparisons when needed. Significance was considered when p < 0.05. Results: Wistar rats fed on a HC diet had a significant increase of LDL-cholesterol levels (p < 0.001) and body weight (p = 0.017), when compared to the control group fed on a normal diet in the period of ten weeks. Moreover, HC diet induced significant morphological alterations of the extracellular matrix of the bladder wall, regarding immature collagen fibers and type III collagen remodeling, when compared to the control group (p = 0.002 and p = 0.016, respectively), resembling the process promoted in the BOO model. Conclusions: A hypercholesterolemic diet in Wistar rats promoted, besides the body weight and LDL-cholesterol increase, morphological alterations of the bladder extracellular matrix, regarding collagen remodeling.