LIPID NUTRITION, MEMBRANE FLUIDITY & SALIVARY GLAND

脂质营养、膜流动性

• 批准号: 3219694
• 负责人: SYED Q ALAM
• 金额: $ 10.4万
• 依托单位: LSU HEALTH SCIENCES CENTER
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-09-01 至 1990-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3219694
• 关键词: adenosinetriphosphatase; adenylate cyclase; cell membrane; cholesterol; dietary lipid; enzyme induction /repression; essential fatty acids; forskolin; ion transport; laboratory rat; linoleate; membrane lipids; membrane proteins; nutrition related tag; ouabain; salivary glands; sodium potassium exchanging ATPase; submandibular gland; unsaturated fats

The purpose of the proposed studies is to further substantiate our working hypothesis that the diet-induced modifications in lipid composition and fluidity of plasma membranes of submandibular glands would result in a modification of the adenylate cyclase complex. The foregoing hypothesis will be tested by feeding rat essential fatty acid deficient-diets, trans fatty acids, saturated fats and cholesterol supplemented diets. All these dietary treatments are known to induce changes in membrane lipids and fluidity. Male, young rats will be fed different diets depending upon the type of study. At various time intervals, rats will be killed, the submandibular glands will be dissected out and plasma membranes will be prepared by using differential centrifugation and sucrose density gradient techniques. Basal, fluoride-, isoproterenol- and forskolin-stimulated adenylate cyclase activity will be determined. The concentration of beta-adrenergic receptor (B/max) and its dissociation constant (K/d) will also be measured. The levels of guanine-binding regulatory proteins and the characteristics of the catalytic subunit of adenylate cyclase will also be measured. In vitro studies with reconstituted membranes will be conducted to further assess the role of membrane lipids in adenylate cyclase activation. Beta-adrenergic stimulated secretion of peroxidase from the dispersed cells from the submandibular glands of rats fed various diets will be measured in vitro as a parameter of gland function. Changes in membrane fluidity will be determined by measuring the fluorescene polarization of diphenylhexatriene. Aliquots of plasma membranes from the submandibular glands will be extracted for lipids and the fatty acid composition of total lipids and phospholipids will be determined by gas chromatography. The degree of unsaturation of lipids, along with cholesterol to phospholipid ratios, will be used as additional criteria to assess membrane fluidity. Data will be stastically analyzed to evaluate the role of diet-induced changes in lipid composition and membrane fluidity in modifying the activities of adenylate cyclase and the secretory ability of the salivary glands.

拟议研究的目的是进一步证实我们的工作 假设饮食引起的脂质成分改变和 颌下腺质膜的流动性会导致 腺苷酸环化酶复合物的修饰。 上述假设 将通过喂养缺乏必需脂肪酸的大鼠饮食进行测试，反式 补充脂肪酸、饱和脂肪和胆固醇的饮食。 所有这些 众所周知，饮食治疗会引起膜脂的变化， 流动性。 根据不同的类型，雄性、幼鼠将被喂食不同的饮食。 学习。 在不同的时间间隔，将老鼠杀死，颌下 将解剖出腺体并使用以下方法制备质膜 差速离心和蔗糖密度梯度技术。 基础、氟化物、异丙肾上腺素和毛喉素刺激的腺苷酸环化酶 活动将被确定。 β-肾上腺素能受体浓度 (B/max) 及其解离常数 (K/d) 也将被测量。 这 鸟嘌呤结合调节蛋白的水平及其特征 腺苷酸环化酶的催化亚基也将被测量。 体外 将进行重组膜研究以进一步评估 膜脂在腺苷酸环化酶激活中的作用。 β-肾上腺素能刺激分散细胞分泌过氧化物酶 来自喂食不同饮食的大鼠的下颌下腺将被测量 体外作为腺体功能的参数。 膜流动性的变化将 通过测量荧光偏振来确定 二苯基己三烯。 下颌下质膜的等分试样 将提取腺体中的脂质和总脂肪酸组成 脂质和磷脂将通过气相色谱法测定。 这 脂质的不饱和度，以及胆固醇与磷脂的不饱和度 比率，将用作评估膜流动性的附加标准。 将对数据进行统计分析，以评估饮食诱导的作用 脂质成分和膜流动性的变化 腺苷酸环化酶的活性和唾液的分泌能力 腺体。