Caracterización histoquímica de las glucoproteínas del aparato respiratorio de diversos vertebrados / María Teresa Castells Mora ; directores Francisco Hernández Calvo, José Fco. ballesta Germán.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. D 259.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-400

Use of the chicken as experimental biomodel in atherosclerosis: supra-aortic lesions

La enfermedad cardiovascular es hoy en día la primera causa de mortalidad en las sociedades desarrolladas. Dada la complejidad del desarrollo de la lesión aterosclerótica en el ser humano resulta interesante investigar en modelos animales en los que dicho proceso sea semejante a la enfermedad humana. El pollo, al igual que otras aves, es capaz de desarrollar arteriosclerosis aórtica y coronaria de forma natural o espontánea, e inducida por una dieta enriquecida en colesterol. Teniendo en cuenta que la mayoría de los trabajos publicados describen las lesiones en segmentos aórticos y la variedad de métodos de inducción de la arteriosclerosis, el objetivo de esta investigación es caracterizar de manera adecuada en el modelo aviar utilizado, las lesiones arterioscleróticas de troncos supra-aórticos en un grupo experimental con respecto a un grupo control. Se emplearon 20 pollos de la raza White Leghorn divididos en dos grupos (control y aterogénico) que recibían una dieta normal o hiperlipémica respectivamente durante un periodo de 6 meses. Se sacrificaron entonces los animales para llevar a cabo el estudio bioquímico del plasma (perfil lipídico), evaluación histológica de los troncos supra-aórticos y valoración semicuantitativa de las lesiones según la clasificación de Stary. Se observaron diferencias estadísticamente significativas entre ambos grupos para los diferentes parámetros bioquímicos estudiados y para la cuantificación del grado de lesión de Stary. En el grupo aterogénico se observó un endotelio conservado, con íntimas muy aumentadas de tamaño (10 veces el tamaño del grupo control) y muy desorganizadas. En conclusión, estos hallazgos confirman el uso del pollo como biomodelo experimental para el estudio de la arteriosclerosis en troncos supra-aórticos, y podrían ser empleados como referencia para futuros estudios intervencionistas.Cardiovascular diseases are considered first cause of human mortality in developed countries. Animal models allow adequate research of atherosclerosis, given the similarities with the human lesions. Chickens may develop spontaneous and also induced atherosclerosis by use of a cholesterol-enriched diet. Most published findings describe aortic lesions in a variety of induction methods. Therefore, the aim of this research is to characterize the used avian model, describing supra-aortic trunk lesions in atherosclerotic chickens and to compare it with control animals. Twenty White Leghorn chickens were used (10 controls fed with a normal diet and 10 atherogenic animals fed with a hyperlipidemic diet, for 6 months). After sacrifice, lipid biochemical parameters were analysed, as well as histologic evaluation of supra-aortic vessels and quantification of lesions following the Stary classification. Statistically significant differences for each parameter were observed between the control and experimental groups. Increased intima layer width with disorganization was observed in atherogenic animals. These findings confirm the use of the chicken as an adequate experimental animal for atherosclerosis, and could be used as a reference for future interventional studies

Effects of atorvastatin on progression - regression of renal injury in hyperlipidemic chickens

Complex interrelationships exist between hyperlipidemia and the progression of renal injury. The aim of this study was to evaluate the impact of high plasma cholesterol and triglyceride levels on renal structure and the effects of atorvastatin on progressionregression of renal injury. One-hundred chickens were divided into five groups: Group A: Standard diet (SD) for 6 months; Group B: Hyperlipidemic diet (HD) for 6 months; Group C: HD for three months and SD during the next 3 months; Group D: HD for 3 months and SD during the next 3 months, when they received oral atorvastatin (3 mg/kg/d); Group E: HD for the whole 6 months, and atorvastatin (3 mg/kg/d) during the last 3 months. Increased a-actine immunostaining was found in glomeruli of groups B and C. An important decrease of immunostaining was observed in glomeruli of atorvastatin treated groups. Group D showed the lowest value for presence of lipids, and significant differences were found with respect to the rest of the groups. The glomeruli of group B presented the highest damage grades and those of group D showed the lowest grades and presented significant differences from the rest of the groups. The combination of atorvastatin therapy and proper diet proved to be effective in promoting renal disease regression. However, the study of several parameters indicates that neither only diet nor atorvastatin in the progression group resulted completely effective in decreasing the progression of the disease

Effect of diet/atorvastatin on atherosclerotic lesions associated to nonalcoholic fatty liver disease in chickens

Comparative histological examination of both liver and the supra-aortic arteries have not previously examined the consequences of atherosclerosis and nonalcoholic fatty liver disease (NAFLD), and their response to diet and atorvastatin therapy. This study evaluates the effects of diet alone or in combination with atorvastatin therapy on the progression/regression of atherosclerosis and its correlation with NAFLD. This research was performed on a cohort of chickens on standard (SD) or hyperlipidemic diets (HD), either with or without atorvastatin therapy. The development of atherosclerotic lesions was assessed by histology, immunohistochemistry and quantitative image analysis and correlated with liver histology. The lowest levels of atherosclerotic lesions were found in animals on the HD for 3 months, followed by 3 months of SD in combination with oral atorvastatin. There was a strong association between the histologic findings of atherosclerosis and those of NAFLD. These studies show that standard diet and atorvastatin therapy can positively affect both arterial and hepatic lesions, influencing the regression of the changes. These results support the hypothesis that NAFLD and atherosclerosis may be actually two aspects of a shared disease and suggest the possibility of regression of both disorders with dietary and pharmacologic manipulations

The effect of the flavonoid diosmin, grape seed extract and red wine on the pulmonary metastatic B16F10 melanoma

Objective: To study the effect of different phenolic compounds and red wine on pulmonary metastatic melanoma. Methods: Swiss mice were inoculated with 5x105 melanocytes B16F10 and given oral doses of diosmin, grape seed extract (GSE) and red wine. A macroscopic count was made of the metastatic nodules on the lung surface and a microscopic study by image analysis of five sections, calculating the implantation percentage and tumoral growth and invasion indices. Results: Macroscopically, the group treated with diosmin showed the greatest reduction (52%) in the number of metastatic nodules compared with the control group, which was treated with ethanol, while GSE and red wine caused decreases of 26.07 and 28.81%, respectively. Microscopically, there was a decrease in the implantation percentage after the administration of diosmin (79.4%) and red wine (20.19%), and an increase of 2.12% after the administration of GSE, all relative to the ethanol-treated control. As regards the growth index, diosmin produced a reduction of 67.44% and red wine a reduction of 20.62%, while GSE again produced an increase (25.33%). The reductions in the invasion index were 45.23, 31.65 and 17.57% with diosmin, GSE and red wine, respectively. Conclusions: Diosmin originated the greatest reduction in pulmonary metastases, both at the macroscopic and microscopic levels

Cytochemical and biochemical evidences for a complex tridimensional structure of the hamster zona pellucida

Zona pellucida (ZP) is an extracellular matrix that surrounds eggs and pre-implantation embryos and is required for in vivo fertility. A key event in successful fertilization is sperm binding to the surface of the ZP. It has been previously described that the hamster sperm binds mainly the outer region of the ZP which corresponds to the porous region in contact with the cumulus cells. Using ultrastructural cytochemistry approaches with an antibody developed against porcine ZP, this study shows that the pig ZP shares epitopes with some rodent species like hamster, rat and mouse. In the hamster, these epitopes are located mainly in the outer region of the ZP of preovulatory and ovulated oocytes. By means of biochemical approaches it was demonstrated that 1) the antibody is specific for the native hamster ZP3, 2) four different bands with a molecular weight of 67, 60, 48 and 38 kDa after Nlinked deglycosylation suggesting that the hamster ZP is formed by four proteins, and 3) the different composition observed in the outer region of the hamster ZP could be due to a specific supramolecular structure that makes some epitopes accessible for the antibodies. In summary, this study provides evidence that the different composition observed in the different regions of the ZP is mediated by a different organization of the components of the ZP produced during the oocyte maturation. This different organization could be responsible for the different sperm binding affinity observed for sperm to the outer region versus the inner region of the ZP

Planimetric and histological study of the aortae in atherosclerotic chickens treated with nifedipine, verapamil and diltiazem

Calcium appears to be involved in many of the cellular events which are thought to be important in atherogenesis. Calcium channel blockers have been shown to reduce arterial lipid accumulation in animals without altering serum cholesterol. Avian models of atherosclerosis offer economic and technical advantages over mammalian models. In this study, we examine the effects of nifedipine, verapamil and diltiazem at clinical and higher doses, on the extent of atherosclerosis of egg-fed chickens. In order to assess the extent of atherosclerosis quantitatively, the aortic lesions of the thoracic and abdominal aorta, aortic arch and supraaortic regions were measured by planimetry. Atherosclerotic lesions were evaluated histologically. Statistically significant reductions in the lipid deposition of the aorta were found in all the treated groups. The extent and distribution of atherosclerotic lesions were decreased in a significant way by verapamil, nifedipine and diltiazem. The higher the dosage used, the higher the regression of the atherosclerotic lesions. At clinical dosage, nifedipine showed the highest decrease of the lesions. In addition, the chicken atherosclerosis model has proved itself useful and very suitable for in vivo drug intervention studies