【作者】 张春飞；

【导师】 冯磊；

【作者基本信息】 浙江大学 ， 营养与食品卫生学， 2003， 硕士

【摘要】 心脑血管疾病已成为危害人类健康的主要疾病，而脂质代谢异常，特别是血胆固醇水平升高是基本易患因素。如何有效调节血脂，是目前营养学研究的热点之一。 目的：研究茶多糖（Tea polysaccharides，TPS）对高脂血症大鼠调节血脂作用及其机理。 方法：雄性SD大鼠50只，体重150～170克，按空腹血清胆固醇和体重随机分为正常对照组（Normal group，Nor）（10只）和造模组（共36只）。造模组经高脂饲料喂饲4周后，选出高脂血症大鼠27只，然后按血清胆固醇和体重随机的原则分为3组（每组9只），即高脂对照组（Control group，Con），低剂量组（Low-dosage group of TPS，TPSⅠ），高剂量组（High-dosage group of TPS，TPSⅡ）。正常对照组予普通饲料，其余三组仍予高脂饲料。以每只大鼠每天3ml的量灌胃将TPS配成两种不同的浓度，其中TPSⅠ每公斤体重100mg，TPSⅡ 200mg，Nor和Con分别予等量生理盐水灌胃，连续2个月。分别于实验第20天（早期），第40天（中期），第60天（晚期）取空腹血清，测定TC，LDL-C，HDL-C，实验晚期同时测定空腹血清LCAT，LPL，HL活性及同一批血清的HDL-C，HDL₃-C，HDL₂-C。实验第60天时，将高脂饲料组改饲普通饲料，一周后，于晚11时至次日凌晨1时处死大鼠取肝脏，用于测定肝脏HMG CoA还原酶比活性和肝脏组织病理学观察。统计方法采用SPSS V 10.0和SAS 8.0。所有数据 浙江人学顾个学位论义 中文摘要均以均数士标准差表示（x士S）。结果： 1．TPS对实验性高脂血症大鼠血脂的影响：（l）．低剂量组实验开始（给子TPS前），及实验的早、中、晚期血清 TC（OI。O川，下同）分别为：3．1310．46，2．8610．66，2．910．45，2．63t0．45，各期 TC较实验开始分别降低 8．6％，7刀％，16．0％，但和给予 TPS前比较无统计学意义（P＞0对引；高剂量组实验开始及实验的早、中、晚期血清＊C分别为3刀2t0．42，3刀9t0二9，2．96t0．34，266f0．门，其中晚期TC较实验开始降低11。9％，有统计学意义叩＜0对引。实验晚期，高脂对照组＊C上升为3．33功．53，和实验开始比较无统计差异，而低剂量和高剂量组与高脂对照组比较分别降低 2］刀％，20．l％，统计均有显著性意义（P＜O．05）。但两组间实验晚期比较无剂量差异。（2）．＊PS有升高HDL－C的趋势。实验的目、中、晚期低剂量组HDL－C（mmol／l，下同）分别为1．32t0．19，1．57f0．38，1．7ito二5，较实验开始（1．39f0．19）分别升高5刀％，12．9％，23刀％，其中晚期升高有显著性差异p＜0．05）；同样高剂量组HD卜C实验的早、中、晚期分别为l．41 10．16，l．71士0．23，l．69士0．20，较实验开始 HDL－C（1．38士0．12）均有升高，其中，中期和晚期HD卜C升高刀刀％和H．5％，差异显著（卜＜0刀5）。实验晚期的低剂量和高剂量组HOLC分别较高脂对照组（1．39f0．12）升高旧．7％和ZI．6％，统计均有显著性差异（卜＜0对引；而且低剂量组HD卜C升高更明显，和正常对照组比较差异显著 p＜005）。但实验晚期两组间比较HD卜C升高无显著性差异。（）．而本实验未能显著降低卜D卜C（P＞0刀5）。 2．TPS对高脂血症大鼠抗动脉粥样因子（HDLC／TC，LDLC／LDL－C）的影响：TPS能显著提高实验组的水平。低剂量和高剂量组HDLC／TC的比值实验开始分别为0．45土0．10，0．46士0．05，实验结束为 0．66士0．08，0．64士0．07，分别较实验开始升高 46．7％和39．1％，比较有显著性意义（P＜0刀5）；低，高剂量组实验结束时的HD卜一＊／＊C比值较同期高脂对照组（0．42t0．06）分别升高 57．］％和 52．4％，比较均有显著性差异（P＜0．05）。而低剂量和高剂量组HDL－C／LDL－C 比值实验结束分别为 卜3810．13，1．33LO，13，和实验开始（l刀切＊2，1．23L0．26）相比虽差异不显著，但实验结束的比值和同期高脂对照组门．13切．13)相比，则差异显著（卜0．05），分别升高221％和 2 浙江大学硕1：学位论义 中文摘要门7％。但TPS对升高两因于无剂量差异。 3茶多糖对高脂血症大鼠 LCAT，LPL，HL，HMG COA还原酶活力的影响： （1）工CAT活力：正常对照组、高脂对照组、低剂量组、高剂量组 LCAT的活力（nlnolFC／ml．h，卜同）分别为 119．05士20．97，57．77士20．35，94．23士20．08，88．62士15．15。结果表明，高脂对照组L＊AT活性明显低于正常对照组（卜＜0刀5），给子＊PS后的两剂量组L＊AT活性均有升高，和高脂对照组比较有显著性意义（卜＜0刀5），但两组间差异不显著。（2）上PL活力：高脂对照组 LPL活力（6．52士2．］6，pmolFFA／ml上，下同）明显低下上常对照组（24．34士5．48）(卜＜0对引，给予＊。S后的低剂量组（门．88士7．67），较高脂对照组有升高，差异显著（P＜0对引八3）爿卜活力：正常对照组（8．38士3．94，川。川FFA／In上丁同）和高脂对照组（5．66上2．20）比?更多还原

【Abstract】 Cerebrovascular and cardiovascular diseases are the most harmful to public health. The main pathogenic factors, especially the high level of blood cholesterol, is the disorder of lipid metabolism. How to regulate the blood lipid effectively is a hotspot on nutriologyresearch.Objective: To investigate the regulation of tea polysaccharides on lipid and its mechanismin hyperlipidemic rats.Methods: Male SD strains rats (150-170g) were randomly divided into one normal group fed normal diet(10 rats) and experimental groups(36 rats) fed high-lipid-diet according to the blood cholesterol and the weight. After the experimental groups were fed high-lipid-diet for four weeks and the models were prepared successfully(27 rats chosen out), they were redivided into three groups: the control group, the low dosage group (TPSI), and the high dosage group (TPSII)(9 rats per group). The normal group was kept on feeding with normal diet while the other three groups with high-lipid-diet. The groups of TPSI and TPSI1 were administrated with TPS at the dosages of 100mg/kg and 200mg/kg, respectively. According to the two dosages, two concentrations of TPS of 3ml per day for one rat were prepared while the normal and the control group with the same volume of 0.9%NS. The experiment lasted two months. During the course, the fast blood cholesterol (TC), low-densitycholesterol (LDL-C), high-density cholesterol (HDL-C), were tested at 20th day (the early stage), 40th day (the mid stage), and 60th day (the late stage).And at the late stage,the activity of the fast blood LCAT, LPL, HL were also determined and meanwhile HDL-C, HDL2-C, HDL3-C were tested using the same share of the plasma.At this time,the groups with high-lipid-diet changed with normal diet.After one week, by the end of the test, the rats were killed at 23 to 1 o’clock and their livers were quickly removed. The activity of liver HMG CoA reductase and the degrees of the fat accumulations on livers were studied. Statistical calculations were performed with commercial package of SAS 8.0 and SPSS V10.0. Values were expressed as means±S.Results:1. The effects on blood lipids in hyperlipidemic rats: (l).The blood TC level of TPSI group at the early stage, mid stage and late stage were decreased 8.6%, 7.0%, 16.0% respectively, but there was no difference compared with those of before administration; The TC level of TPSII group was decreased 11.9% significantly at the late stage compared with that of before administration. After given TPS for two months, compared with the control group, the TC level of two experimental groups were reduced 21.0% and 20.1% significantly. However, there was no difference between the two experimental groups (P>0.05). (2).TPS played an important role on increasing the concentration of blood HDL-C. The value of HDL-C in TPSI group were increased 12.9% and 23.0% at the mid stage and late stage compared to those of before administration, thereinto the value at the late stage increased significantly; while the TPSII group were elevated 23.9% and 22.5% markedly at the same time. At the end of the experiment, the level of HDL-C in TPSI and TPSII groups were increased 18.7% and 21.6% significantly compared with the control group. (3). TPS has no significant effect on the concentration of the fast blood LDL-C.2. The effects on the anti-arteriosclerosis factors (HDL-C/TC, HDL-C/LDL-C): The two ratios could be elevated greatly. The ratios of HDL-C to TC (HDL-C/TC) in TPSI and TPSII groups were increased 46.7% and 39.1% compared to those of before administration,while increased 57.1% and 52.4% compared to the control group (P0.05). Although TPS couldn’t increase the ratio of HDL-C to LDL-C (HDL-C/LDL-C) compared to that of before administration, its value in the two experimental groups, compared to the control group, was respectively elevated 22.1% and 17.7% markedly (PO.05).3. The effects on the activities of LCAT, LPL, HL and HMG CoA reductase: (1). LCAT: The activity of LCAT in control group was lowered greatly th更多还原