SERUM GLYCOPROTEIN CHANGES IN THE BB/W DIABETIC RAT

糖尿病的特征是缺乏胰岛素， 高血清葡萄糖浓度（高血糖症）， 与一些碳水化合物异常有关， 疾病的病理影响，包括 几种血清糖蛋白，组织糖蛋白异常 例如基底膜蛋白，以及改变的细胞表面 淋巴细胞和其他细胞中的糖蛋白。 的影响 糖尿病、高血糖或低胰岛素浓度 寡糖的结构和合成是未知的。 的目的 该建议是检查血清糖蛋白结构， 在BB/W糖尿病大鼠模型中体内和体外合成 I型糖尿病（青少年发病） 这里提出的许多研究将集中在结构和 结合珠蛋白的合成，因为我们的初步研究表明， 这种糖尿病蛋白质显然有一种新的异常， 其Asn连接的寡糖。 其他研究将 进行扁豆凝集素结合蛋白，因为我们的初步 研究表明，改变了几个BB/W的小扁豆凝集素结合 糖尿病大鼠血清糖蛋白 将对触珠蛋白和其他血清蛋白进行研究 由糖尿病前期、控制良好的糖尿病患者和 控制不佳的糖尿病大鼠，以确定 观察到的糖蛋白变化、 以及血糖控制好与差。 为了 确定高血糖对糖蛋白生物合成的影响 在体外，结合珠蛋白和其它糖蛋白合成将 在以下条件下在灌注的大鼠肝脏或肝细胞中检查： 正常或过量的葡萄糖，以及正常或缺乏胰岛素， 在正常和糖尿病血清中发现的条件。 方法 体内和体内合成寡糖的结构分析 体外将包括碳水化合物组成、凝集素亲和力 层析，外切和内切糖苷酶消化，和 甲基化

Diabetes mellitus is characterized by a lack of insulin, and by high serum glucose concentrations (hyperglycemia) which can be correlated with some carbohydrate abnormalities and many pathological effects of the disease, including elevated levels of several serum glycoproteins, abnormalities in tissue glycoproteins such as basement membrane proteins, and altered cell surface glycoproteins in lymphocytes and other cells. The effects of diabetes, high glucose or low insulin concentrations on oligosaccharide structure and synthesis are unknown. The aim of this proposal is to examine serum glycoprotein structure and synthesis in vivo and in vitro in the BB/W diabetic rat, a model for type I (juvenile onset) diabetes. Many of the studies proposed here will focus on the structure and synthesis of haptoglobin, since our preliminary studies have shown that this diabetic protein apparently has a novel abnormality in its Asn-linked oligosaccharides. Additional studies will be performed on lentil-lectin binding proteins, since our preliminary studies showed altered lentil-lectin binding of several BB/W diabetic rat serum glycoproteins. Studies will be performed on haptoglobin and other serum proteins synthesized in vivo by prediabetic, well-controlled diabetic and poorly controlled diabetic rats, in order to determine the correlation between the glycoprotein changes observed, the onset of diabetes, and good versus poor glucose control. In order to determine the effects of hyperglycemia on glycoprotein biosynthesis in vitro, synthesis of haptoglobin and other glycoproteins will be examined in perfused rat liver or hepatocytes under conditions of normal or excess glucose, and normal or absent insulin, mimicking conditions found in normal and diabetic serum. Methods of structural analysis of oligosaccharides synthesized in vivo and in vitro will include carbohydrate composition, lectin affinity chromatography, exo- and endoglycosidase digestion, and methylation.