METABOLISM OF BETA-CAROTENE IN HYPOCAROTENEMIC PATIENTS

一些患有脑血管意外（CVA）的患者（pts） 下咽部和食管上部的严重运动障碍导致 无法吞咽并需要永久性肠内喂养。 后 几个星期后，这些病人发展为低胡萝卜素血症，因为他们的肠 饲料配方中不含类胡萝卜素，但含有足够的类胡萝卜素， 微量营养素和常量营养素。 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，因为他们的胃肠道是 它们的饮食可以在很长一段时间内严格控制， 观察. 本研究旨在研究：1）BC的吸收; 2）血浆， 皮肤和脂肪组织BC水平; 3）生理或病理 影响该化合物对脂质过氧化作用的各种组织水平， 白细胞功能;和4）脂质和水溶性抗氧化剂水平， 低胡萝卜素血症患者，随后补充了分级剂量的 公元前 最初，血清类胡萝卜素和其他抗氧化剂的水平， 将筛选接受肠内喂养的CVA患者。 只有那些正常的 营养状况和发展血清BC水平低于正常的1 1/2 SD (mean 33 +或-20.5微克/分升）将被纳入本研究。 40名患者将 将在试点框架内对其中5名进行研究， 研究，以完善测试方法及其协调。 的 剩余的35名患者将被随机分为5组，每组7名患者。 这些群体 是：1）组I无BC（对照），和2）组II、III、IV和V将 分别以3、15、30和180 mg/天的剂量接受BC， 在研究开始时，将对他们进行评估， 他们对指定剂量的BC的急性反应， 第0天和第1天分配的剂量。 在第0天，将对其进行评价 对于基线水平的血清和组织储存的BC，血清脂质 过氧化参数（LPP），（呼吸碳氢化合物，血清脂质过氧化物， GSSG、GSH）、白细胞功能、水溶性和脂溶性抗氧化剂以及 维生素A的吸收 在第1天，将评估患者的急性 在12小时内对BC作出反应。 他们将继续 补充并每2周检测一次血清类维生素A， 类胡萝卜素、其他抗氧化剂、血清LPP和呼吸碳氢化合物。 后 10周的补充，他们将通过相同类型的评估 作为第0天和第1天。 停药后4周和10周， 类维生素A类胡萝卜素，其他抗氧化剂，呼吸碳氢化合物和血清 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.