METABOLISM OF BETA-CAROTENE IN HYPOCAROTENEMIC PATIENTS

一些脑血管意外(CVA)患者发展为 严重的下咽和上食道运动障碍 吞咽困难，需要长期的肠道喂养。之后 几周后，这样的患者会出现低胡萝卜素血症，因为他们的肠道 配方奶粉不含类胡萝卜素，但含有适量 微量和大量营养素。这样的PTS提供了一个独特的学习机会 β-胡萝卜素(BC)的代谢是因为他们的胃肠道 完好无损，他们的饮食可以在很长一段时间内得到严格控制 观察。本研究的目的是研究：1)BC的吸收；2)血浆， BC的皮肤和脂肪组织水平；3)生理或病理 该化合物的不同组织水平对脂质过氧化的影响，以及 白细胞功能；以及4)体内脂质和水溶性抗氧化剂水平 患有低胡萝卜素血症的PTS，后来补充了分级剂量的 公元前。最初，血清中类胡萝卜素和其他抗氧化剂的水平 将对肠道喂养的CVA患者进行筛查。只有那些正常的 营养状况和发展到血清BC水平低于正常的1 1/2 SD (平均33或-20.5ug/dl)将被纳入这项研究。40分将 其中五人将在试点框架内进行研究 研究以完善测试方法及其协调。这个 其余35例随机分为5组，每组7例。这些团体 分别是：1)I组不含BC(对照)；2)II、III、IV和V组 每日分别服用BC 3、15、30和180毫克，疗程为 周期为10周。在研究开始时，将对他们进行评估 他们对分配给他们的BC剂量的急性反应是服用安慰剂 第0天及其在第1天分配的剂量。在第0天，将对它们进行评估 为基础水平的血清和组织储存的BC，血脂 过氧化参数(LPP)，(呼气烃，血清过氧化脂质， GSSG、GSH)、白细胞功能、水和脂溶性抗氧化剂以及 维生素A的吸收。在第一天，PTS将被评估其急性 在12小时内对BC作出回应。他们将继续他们的 并将每两周检测一次血清维甲酸， 类胡萝卜素，其他抗氧化剂，血清LPP和呼气烃。之后 10周的补充，他们将接受同样类型的评估 在停用BC后4周和10周，血清中 类维甲酸、类胡萝卜素、其他抗氧化剂、呼气烃和血清 将重复LPP。

Some of the patients (pts) with cerebro-vascular accident (CVA) develop a severe motility disorder of the hypopharinx and upper esophagus resulting in inability to swallow and require permanent enteral feeding. After several weeks, such pts develop hypocarotenemia because their enteral feeding formulas are devoid of carotenoids while containing adequate amount of micro and macronutrients. Such pts offer a unique opportunity to study the metabolism of Beta-Carotene (BC) since their gastrointestinal tract is intact and their diet can be strictly controlled over a prolonged period of observation. This research aims to study: 1) absorption of BC; 2) plasma, skin and fat tissue levels of BC; 3) the physiological or pathological effects various tissue levels of this compound on lipid peroxidation, and leukocyte functions; and 4) lipid and water soluble antioxidants levels in pts who are hypocarotenemic and later supplemented with graded doses of BC. Initially, the serum levels of carotenoids and other antioxidants of CVA pts on enteral feeding will be screened. Only those that are in normal nutritional condition and develop a serum BC level below 1 1/2 SD of normal (mean 33 + or -20.5 ug/dl) will be admitted to this study. Forty pts will be recruited, five of them will be studied in the framework of a pilot study in order to refine the testing methodology and its coordination. The remaining 35 pts will be randomized into 5 groups of 7 pts. These groups are: 1) Group I no BC (control), and 2) Groups II, III, IV and V will receive BC in doses of 3, 15, 30 and 180 mg per day respectively for a period of 10 wks. At the beginning of the study, they will be assessed for their acute response to their assigned doses of BC by taking a placebo on Day 0 and their assigned dose on Day 1. On Day 0, they will be evaluated for baseline levels of serum and tissues stores of BC, serum lipid peroxidation parameters (LPP), (breath hydrocarbons, serum lipid peroxides, GSSG, GSH), leukocyte functions, water and lipid soluble antioxidants and vitamin A absorption. On Day 1, pts will be assessed for their acute response to BC over a 12 hour time period. They will continue their supplementation and will be tested every 2 wks for serum retinoids, carotenoids, other antioxidants, serum LPP and breath hydrocarbons. After 10 wks of supplementation, they will go through the same type of evaluation as Days 0 and 1. At 4 and 10 wks after withdrawal of BC, serum levels of retinoids carotenoids, other antioxidants, breath hydrocarbons and serum LPP will be repeated.