DIABETES MELLITUS AND ISLET AMYLOID IN ADULT FELINES

一种以前未知的推定的多肽激素，被鉴定为 胰岛淀粉样多肽(IAPP)是最近从胰岛中提纯的 猫和人类2型糖尿病(DM)的淀粉样蛋白(IA)。 因为IAPP衍生淀粉样蛋白代表了最典型的 胰岛病变在糖尿病的发生发展中起重要作用。 猫和人，有关生产和功能的信息 IAPP的研究可能为糖尿病的发展提供新的见解 与衰老相关的。我们广泛而长期的目标是 描述IAPP前体的生产和功能，以及 进一步阐明IAPP与DM的关系。这些 目标将通过一系列实验来实现 旨在： 1.比较IA来源的IAPP的一级化学结构 多发性糖尿病猫(高效液相色谱和氨基酸序列分析) 与IAPP或IAPP前体分离(通过亲和层析 从正常猫的胰腺或血清中分离)。具体来说， 我们希望调查某些结构性事件的可能性 糖尿病患者IAPP的异常与转化为 淀粉样纤维； 2.比较糖尿病猫和非糖尿病猫IAPP-前体的产生 (即血糖正常和血糖正常的猫 公差(IGT)。猫的分类将根据对 空腹血糖、RIA胰岛素/胰高血糖素水平和尿液分析 在静脉注射葡萄糖耐量试验前。LAPP-前体生产将 用免疫细胞化学方法检测胰腺B细胞 用放射免疫法测定血清IAPP。胰腺将会是 组织学(刚果红)评估-红色)评估以确定 如果非糖尿病猫的LA沉积是IGT或 处于“糖尿病前期”状态； 3.阐明正常人IAPP产生的分子生物学 胰岛，IGT和DM中也有。LAPP基因将从 Lambda gt11文库(分离胰岛mRNA后获得) 寡核苷酸探针和单特异性多克隆抗体。 IAPP在正常IGT和DM猫中的表达将通过IN 原位杂交、体外翻译、Northern杂交； 4.评价人工合成人IAPP和人工合成IAPP的效果 IAPP片段对胰岛激素分泌的影响 (即胰岛素、胰升糖素、生长抑素和胰多肽) 采用大鼠和猫胰腺直接灌注法。此外，我们 将评估大鼠和猫的胰腺和受体结合分析； 5.从Decus(Octdon Decus)中分离的IA的化学性质， 采用我们采用的猫的提取和纯化方法 和人类智囊团。淀粉样蛋白样品将通过大小排除提纯 反相高效液相色谱法用于随后的氨基酸测序。

A previously unknown putative polypeptide hormone identified as islet amyloid polypeptide (IAPP) was recently purified from islet amyloid (IA) of cats and humans with TYPE 2 diabetes mellitus (DM). In that IAPP -derived amyloid represents the most characteristic islet lesion in this from of DM in into the development of DM in cats and humans, information concerning the production and function of IAPP may provide new insights into the development of DM associated with aging. Our broad, long term objectives are to characterize the production and function of the IAPP-precursor, and to further elucidate the relationship of IAPP to DM. These objectives will be achieved through a series of experiments designed to: 1. Compare the primary chemical structure of IA-derived IAPP from multiple diabetic cats (by HPLC and amino acid sequence analysis) with that of IAPP or an IAPP precursor isolated (by affinity column separation) from pancreas or serum of normal cats. Specifically, we wish to investigate the possibility that certain structural aberrations in IAPP of diabetics are linked to transformation into amyloid fibrils; 2. Compare IAPP-precursor production in cats with and without DM (i.e., normal and normogylycemic cats with impaired glucose tolerance (IGT). Cats will be categorized by evaluations of fasting blood glucose, RIA insulin/glucagon levels and urinalysis prior to IV glucose tolerance test. LAPP-precursor production will be evaluated by immunocytochemical analysis of pancreatic B cells and by determination of serum IAPP using RIA. Pancreases will be histologically (Congo red) evaluated-red) evaluated to determine if LA deposits in nondiabetic cats are early reflections of IGT or a "prediabetic" state; 3. Elucidate the molecular biology of IAPP production in normal islets, and also in IGT and DM. LAPP cDNA will be obtained from a lambda gt11 library (obtained after isolation of islet mRNA) using oligonucleotide probes and monospecific polyclonal antibodies. IAPP expression in normal IGT and DM cats will be examined by in situ hybridization, in vitro translation, and Northern blotting; 4. Evaluate the effects of synthetic human IAPP and synthetic fragments of IAPP on the secretion of pancreatic islet hormones (i.e. insulin, glucagon, somatostatin, and pancreatic polypeptide) using direct perfusion of rat and cat pancreas. In addition, we will evaluate rat and cat pancreas and receptor binding assays;. 5. Chemically characterize IA from degus (Octodon degus), employing extraction and purification methods used by us for cat and human IA. Amyloid samples will be purified by size exclusion and revered phase HPLC for subsequent amino acid sequencing.