Beaufrère H, Nevarez J G, Wakamatsu N, Clubb S, Cray C, Tully T N
Veterinary Clinical Sciences, LSU-School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge 70808, LA, USA. Email:
Vet Pathol. 2013 Nov;50(6):1116-26. doi: 10.1177/0300985813488958. Epub 2013 May 21.
Spontaneous atherosclerosis is common in psittaciformes, and clinical signs associated with flow-limiting stenosis are encountered in pet birds. Nevertheless, a psittacine model of atherosclerosis has not been developed for research investigations. Sixteen captive-bred Quaker parrots (Myiopsitta monachus) were used in this study. While 4 control birds were fed a maintenance diet, 12 other birds were fed an atherogenic diet composed of 1% cholesterol controlling for a calorie-to-protein ratio for periods ranging from 2 to 8 months. The birds were euthanized at the end of their respective food trial period. Histopathology, transmission electron microscopy, and cholesterol measurement were performed on the ascending aorta and brachiocephalic and pulmonary arteries. Plasma lipoproteins, cholesterol, and triglycerides were also measured on a monthly basis. Significant atherosclerotic lesions were induced within 2 months and advanced atherosclerotic lesions within 4 to 6 months. The advanced lesions were histologically similar to naturally occurring lesions identified in the same parrot species with a lipid core and a fibrous cap. Ultrastructurally, there were extracellular lipid, foam cell, and endothelial changes. Arterial cholesterol content increased linearly over time. Plasma cholesterol and low-density lipoprotein (LDL) significantly increased over time by an average of 5- and 15-fold, respectively, with a shift from high-density lipoprotein to LDL as the main plasma lipoprotein. Quaker parrots also exhibited high plasma cholesteryl ester transfer protein activity that increased, although not significantly, over time. This experiment demonstrates that in Quaker parrots fed 1% cholesterol, advanced atherosclerosis can be induced relatively quickly, and lesions resemble those found in other avian models and humans.
自发性动脉粥样硬化在鹦鹉目中很常见，宠物鸟中会出现与血流限制性狭窄相关的临床症状。然而，尚未开发出用于研究调查的鹦鹉动脉粥样硬化模型。本研究使用了16只人工饲养的和尚鹦鹉（Myiopsitta monachus）。4只对照鸟喂食维持性日粮，另外12只鸟喂食由1%胆固醇组成的致动脉粥样化日粮，控制热量与蛋白质的比例，持续2至8个月。在各自的食物试验期结束时对这些鸟实施安乐死。对升主动脉、头臂动脉和肺动脉进行组织病理学、透射电子显微镜检查和胆固醇测量。每月还测量血浆脂蛋白、胆固醇和甘油三酯。2个月内诱发了明显的动脉粥样硬化病变，4至6个月内出现了晚期动脉粥样硬化病变。晚期病变在组织学上与在同一鹦鹉物种中发现的自然发生的病变相似，有脂质核心和纤维帽。在超微结构上，有细胞外脂质、泡沫细胞和内皮变化。动脉胆固醇含量随时间呈线性增加。血浆胆固醇和低密度脂蛋白（LDL）随时间显著增加，平均分别增加了5倍和15倍，血浆脂蛋白的主要成分从高密度脂蛋白转变为LDL。和尚鹦鹉还表现出较高的血浆胆固醇酯转移蛋白活性，该活性随时间增加，尽管不显著。本实验表明，喂食1%胆固醇的和尚鹦鹉可相对快速地诱发晚期动脉粥样硬化，其病变与其他鸟类模型和人类中发现的病变相似。
