人血浆HDL对高脂饲养家兔肝细胞膜HDL受体活性的影响

为进一步探讨ＨＤＬ对抗动脉粥样硬化的作用机理,采用高胆固醇膳食饲养家兔,通过静脉注射人血浆ＨＤＬ制剂,观察ＨＤＬ对高脂饲养家兔血脂、肝脏和胆囊胆汁脂质含量以及肝细胞膜ＨＤＬ受体活性的影响。结果发现：ＨＤＬ制剂虽无降低高脂饲养家兔血清脂质的作用,但可减少其肝脏脂质沉积,并且具有促进脂质经胆道排泄的作用。高脂饲养家兔的肝细胞膜ＨＤＬ受体具有Ｋｄ 值减小,Ｂｍ ａｘ 值增加的趋势;注射ＨＤＬ制剂的家兔,与正常对照比较,其Ｋｄ 值虽无明显变化,但Ｂｍ ａｘ 值显著增加（Ｐ＜ ０．０５）,表明注射人血浆ＨＤＬ可使高脂饲养家兔肝细胞膜ＨＤＬ受体呈现以受体数目增加为特征的活性升高。     

免胆囊结石成石过程中脂代谢的变化及高密度脂蛋白制剂对其影响 …

为研究高胆固醇食诱发兔胆囊胆固醇结石模型的脂代谢变化,以及高密脂蛋白对其脂代谢及成石的影响,将动物随机分为对照组,高胆固醇食组及高胆固醇膳食＋ＨＤＬ注射组,观察各组血浆脂质,胆汁中胆固醇,血卵磷脂胆固醇酰基转移酶活性及血和胆汁中胆汁酸及成率的变化 。     

兔胆囊结石成石过程中脂代谢的变化及高密度脂蛋白制剂对其影响的研究

为研究高胆固醇膳食诱发兔胆囊胆固醇结石模型的脂代谢变化,以及高密度脂蛋白（ＨＤＬ）对其脂代谢及成石的影响,将动物随机分为对照组、高胆固醇膳食组及高胆固醇膳食＋ＨＤＬ注射组,观察各组血浆脂质、胆汁中胆固醇、血卵磷脂胆固醇酰基转移酶（ＬＣＡＴ）活性及血和胆汁中胆汁酸及成石率的变化。结果显示：动物体内胆固醇等脂质的消除障碍导致体内脂质的大量堆积以及清除紊乱,是高胆固醇膳食诱发兔胆囊结石脂代谢变化的主要特点,胆汁中胆固醇与胆汁酸的清除比例失调可能导致成石性胆汁形成;尽管外源性ＨＤＬ制剂能够升高血浆ＨＤＬ２－Ｃ／ＨＤＬ３－Ｃ的比值,增加ＬＣＡＴ的活性从而促使ＨＤＬ成熟,并能降低肝脏的胆固醇含量,但未能降低成石率。结果表明外源性ＨＤＬ制剂对兔胆囊结石形成中脂代谢有一定的影响,但抗成石作用不明显     

CHARACTERIZATION OF HDL BINDING SITES AND ITS LIGAND IN CULTURED SMOOTH MUSCLE CELLS OF RABBIT''S AORTA

Cultured smooth muscle cells of rabbit aorta were studied by 125I labelled rabbit HDL3. Saturation curves, measured at 4 C, showed the presence of two different components: the low-affinity non-saturable binding portion and the high-affinity binding portion (Kd about 5.6 x 10(-8) mol/L and Bmax about 0.321 micrograms/mg cell protein). Scatchard analyses of the high-affinity binding portion suggest the presence of single class binding sites. Binding of rabbit HDL3 to cultured smooth muscle cells was relatively resistant to trypsin or pronase, and independent to Ca2+. The binding rate of 125I-HDL3 to the smooth muscle cells was highest at 4 C and the optimal pH was 2. Additionally, presence of high concentration apoAI reduced 50% of the binding rate of 125I-HDL3, and 125I-HDL3, being pretreated (blocked) with rat anti-rabbit apoAI IgG of different concentrations lost 70% of its original binding rate with smooth muscle cells. The results suggest that rabbit aorta smooth muscle cells possess a specific binding sites for apoE-free HDL which recognizes apoAI as a ligand.     

肝性脂酶及脂蛋白脂酶在兔胆囊结石形成过程中的变化及意义

为研究肝脂酶及脂蛋白脂酶在胆固醇结石成石过程中的变化及其对成石的影响,采用高胆固醇膳食诱发兔胆囊胆固醇结石模型,观测对照组及高胆固醇膳食１、２、３、４周组动物血浆脂蛋白脂酶（ＬＰＬ）、肝脂酶（ＨＬ）活性、血浆脂蛋白胆固醇及胆汁中甘氨胆酸（ＧＣＡ）、甘氨脱氧胆酸（ＧＤＣＡ）、胆固醇的变化。结果显示：随着进食高胆固醇膳食时间的增加,血中ＬＰＬ活性增高明显（ｐ〈０．０５）;ＨＬ活性也逐渐升高,３周组及４     

肝性脂酶及脂蛋白脂酶在兔胆囊结石形成过程中的变化及意义

为研究肝脂酶及脂蛋白脂酶在胆固醇结石成石过程中的变化及其对成石的影响,采用高胆固醇膳食诱发兔胆囊胆固醇结石模型,观测对照组及高胆固醇膳食1、2 、3、4周组动物血浆脂蛋白脂酶(LPL)、肝脂酶(HL)活性、血浆脂蛋白胆固醇及胆汁中甘氨胆酸(GCA)、甘氨脱氧胆酸(GDCA)、胆固醇的变化.结果显示:随着进食高胆固醇膳食时间的增加,血中LPL活性增高明显(P＜0.05);HL活性也逐渐升高,3周组及4 周组与对照组差异显著(P＜0.05);血中VLDL-C、LDL-C及胆汁中胆固醇也明显升高(P ＜0.05);而血中 HDL-C、HDL2-C及HDL3-C以及胆汁中GCA、GDCA无明显变化(P＞0.05).结果表明:LPL及HL活性升高可能使肝脏摄取及向胆汁中排泌胆固醇增加,进而影响结石形成.     

载脂蛋白AⅠ,CⅠ,CⅡ,CⅢ,E对肝细胞膜高密度脂蛋白...

Effects of purified human apolipoproteins AI, CI, CII, CIII-1, Cs and E on the binding of 125I-labeled apo E-deficient HDL3 to isolated rat liver plasma membranes were investigated. Unlabeled apo AI, CI, CII, CIII-1 and apo Cs, but not apo E, could effectively inhibit 125I-labeled HDL3 binding to liver membranes, apoCIII-1, was the strongest among the apoC subclasses and the inhibition curve of apoCIII-1 was similar to that of apo AI. This result indicates that apo C, especially apo CIII, may be another specific ligand of HDL receptor, and it plays an important role in regulation of HDL receptor activity in liver.     

脑梗死患者血脂水平与HDL亚类组成的关系

目的 研究脑梗塞患者高密度脂蛋白(HDL)亚类组成及相对含量的变化,并探讨脑梗塞患者血脂水平与HDL亚类组成的关系.方法 用全自动生化分析仪测定血脂及载脂蛋白含量;采用双向电泳-免疫印记检测法分析HDL各亚类组成情况.结果 脑梗塞患者血浆preβ 1-HDL、HDL3a水平显著升高(P＜0.01),HDL2a、HDL2b含量显著降低(P＜0.01);按血浆甘油三酯(TG)浓度将脑梗塞患者分为4组,随血浆TG水平的升高,preβ 1-HDL、HDL3a与HDL3b含量逐渐增加,而HDL2a和HDL2b水平逐渐减小;按血浆HDL-C浓度将脑梗塞患者分为3组,随着HDL-C浓度的升高,preβ1-HDL、HDL3a及HDL3b水平逐渐降低,HDL2a和HDL2b水平逐渐升高.结论 脑梗塞患者血浆HDL颗粒有变小趋势,并且随着TG水平的升高和HDL-C水平的下降,HDL颗粒减小更显著.     

Alpha-1 adrenergic receptors in liver plasma membranes of cirrhotic patients with portal hypertension: a quantitative study

OBJECTIVE: To investigate the changes of alpha-1 adrenergic receptors in cirrhotic liver and the relationship between the changes and the pathogenesis of portal hypertension. METHODS: The concentration and affinity of alpha-1 adrenergic receptors in the liver plasma membranes of posthepatitic cirrhotic patients with portal hypertension were quantitatively measured using radioligand binding analysis. RESULTS: Compared with 8 controls without hepatic pathological changes, the maximal binding capacity (Bmax) of 9 posthepatitic cirrhotic patients decreased (129.1 +/- 12.0 vs 142.1 +/- 14.1 fmol/mg protein, P > 0.05), dissociation constant (Kd) values increased (0.3945 +/- 0.0974 vs 0.2382 +/- 0.0548 nmol/L, P < 0.01), and the receptor maximal content (RMC) decreased (417.4 +/- 76.8 vs 739.9 +/- 167.6 fmol/g liver, P < 0.01). CONCLUSIONS: The decreased concentration and affinity of alpha-1 adrenergic receptors may play an important role in the metabolic disturbances of catecholamines often seen in some cirrhotic patients, and have implications in the pathogenesis of portal hypertension.     

家兔主动脉平滑肌细胞HDL3受体及配体特性的探讨

应用同位素标记高密度脂蛋白_3(HDL_3),探讨家兔主动脉平滑肌细胞HDL_3的结合部位及其影响因素。结果表明,在平滑肌细胞表面存在具有特异性、高亲和力的HDL_3受体(Bmax=0.31μg/mg细胞蛋白,KD=5.6×10~(-8)mol/L)。培养液中的高浓度apoA_1可抑制~(125)I-HDL_3结合量的50％;用大鼠抗apoA_2抗体封闭~(125)I-HDL_3,其结合量可下降70％,而~(125)I-HDL_3与胆固醇预孵育,其与平滑肌细胞的结合率不受影响,提示apoA_1在HDL_3与受体结合过程中起着主要作用。培养液的pH在6.0～8.0之间,不影响HDL_3的结合;HDL_3结合部位对胰酶和裂解蛋白酶(pronase)处理均不敏感,且不依赖于Ca~(2+);4℃时其结合量最大。这些特性均与LDL受体不同,提示在平滑肌细胞表面存在着不同于apoB、E、apoE受体的HDL_3受体。     

胰岛素及其受体在肾缺血再灌注损伤中的作用

目的　探讨肾缺血再灌注 (IR)过程中胰岛素及其受体的作用。方法　采用钳夹肾动脉的方法建造急性缺血再灌注肾损伤模型。将大耳白兔分为对照组、单纯缺血再灌注组 (IR组 )、胰岛素处理组 (Ins+IR组 ) 3组 ,Ins+IR组再灌注的同时给予胰岛素溶液 (Ins3U/ kg.wt) ,而对照组和 IR组则给予等量生理盐水。测定各组动物的血糖、血清胰岛素水平及肾组织胰岛素受体高、低亲和力常数 (Kd1 ,Kd2 )和高、低亲和力受体最大结合容量(Bmax1 ,Bmax2 )。结果　缺血再灌注 2 h后 ,3组动物血糖值、血清胰岛素水平均较术前显著升高 (P<0 .0 5 ) ,IR组尤为显著 ,IR组 Kd1 、Kd2 、Bmax1 、Bmax2 均较对照组显著降低 (P<0 .0 5 ) ,Ins+IR组仅 Bmax2 较对照组显著降低 (P<0 .0 5 ) ;4 8h后 ,3组动物血糖值恢复至正常水平 ,对照组胰岛素水平恢复至正常水平 ,IR组也较 2 h时明显下降(P<0 .0 5 ) ,但仍明显高于对照组 (P<0 .0 5 ) ,3组动物 Kd1 、Bmax1 值无差异 ,Ins+IR组 Bmax2 仍维持较低水平 (P<0 .0 5 ) ,Ins组 Kd2 明显高于对照组 (P<0 .0 5 )。结论　在肾 IR过程中 ,内源性胰岛素的作用减弱 ,外源性胰岛素对肾组织高亲和力受体位点无下降调节作用 ,但胰岛素可引起低亲和力受体数目的下调。胰岛素减轻 IR肾损伤的作用主要是     

The primary study on purification, characterization and function of rabbit serum HDL

Rabbit serum HDL was isolated by gradient ultracentrifugation, found to be pure on PAGE, and characterized by PAGIF. The effect of HDL on normal and hyperlipidemic uptake of LDL into SMC through LDL receptors in rabbits was observed in three experiments. The percentage decrease between normal groups with and without HDL was small (2.3%, 5.5%, 7.3%), while the percentage decrease between hyperlipidemic groups with and without was large (23%, 25%, 26%). The results demonstrate that HDL affects the uptake of hyperlipidemic LDL into SMC through LDL receptors. This suggests that HDL might regulate the cholesterol overloading in cells in cases of hyperlipidemic LDL. The mechanism of HDL action is discussed.     

Effects of yin-tonics and yang-tonics on serum thyroid hormone levels and thyroid hormone receptors of hepatic cell nucleus in hyperthyroxinemic and hypothyroxinemic rats

Hyperthyroxinemia model was made by giving thyroid tablet suspension to Wistar rats and hypothyroxinemia model was made by thyroidectomy. We measured serum thyroid hormone levels by RIA and the parameters of triiodothyronine receptors in rat hepatic cell nucleus by radio-ligand binding assay: Maximal binding capacity (Bmax) and Dissociation constant (Kd). It is found that (1) Yin-tonics can lower serum thyroid hormone levels and Bmax of hepatic nuclear T3R of hyperthyroxinemia rat from 167.14 +/- 25.62 fmol/100 micrograms DNA to 98.98 +/- 15.24 fmol/100 micrograms DNA, P less than 0.001. (2) Both Yang-tonics I and II can raise serum thyroid hormone levels of hypothyroxinemia rats, but not Bmax of hepatic nuclear T3R. Yang-tonics I even lowers Bmax. All the Chinese herbs have no effect on the Kd of rat hepatic nuclear T3R. The results may have some value in studying the effects of Chinese medical drugs.     

维生素E对兔血清LCAT活性及脂类含量的影响

观察了不同剂量VitE对实验性高胆固醇膳食家兔血清LCAT活性、脂类和脂蛋白水平的影响。结果表明,VitE能升高实验兔血清LCAT活性;降低血清总胆固醇和甘油三酯及(LDL+VLDL)-C水平,大剂量VitE的作用更为明显。VitE升高HDL-C的效应与剂量关系不大。表明VitE能通过改善脂类代谢影响动脉粥样硬化的进展。     

高脂膳食诱发家兔血清LPO升高及LDL,VLDL和HDL在活体内的氧化修饰

为探讨高脂膳食对家兔血清过氧化脂质升高和ＬＤＬ、ＶＬＤＬ，特别是ＨＤＬ氧化修饰的影响。正常对照组（ｎ＝８）喂以普通饲料，高脂实验组（ｎ＝８）用高胆固醇饲料（普通饲料加５％猪油，另每只兔加喂０．５ｇ胆固醇）喂养１２周。兔血清ＬＤＬ、ＶＬＤＬ及ＨＤＬ用密度梯度超速离心法分离得到。ＬＤＬ、ＶＬＤＬ及ＨＤＬ的氧化修复用琼脂糖凝胶电泳、２３４ｎｍ光吸收及ＴＢＡＲＳ荧光检测进行鉴定。结果显示：高脂实验组兔血清     

黄须菜籽油抗动脉粥样硬化和抗衰老作用的实验研究——Ⅰ.黄须菜籽油抗动脉粥样硬化作用的实验研究

研究了黄须菜籽油对血清脂肪酸组成、VitE和硒含量变化的影响,并观察了对新西兰兔血小板聚集功能、血脂和血浆脂蛋白的影响。结果表明,饲喂兔黄须菜籽油后,血清棕榈酸明显降低,亚油酸、VitE和硒含量明显升高,使ADP或胶原诱导所致的血小板聚集作用明显减弱,在等热量、等胆固醇条件下TCh,TG,(VLDL+LDL)-Ch降低,HDL-Ch,HDL_2-Ch升高,(VLDL+LDL)-Ch/HDL-Ch比值降低;提示黄须菜籽油有抗动脉粥样硬化的作用。     

输精管结扎与吻合术后前列腺胞核雄激素受体的变化

日本大耳白雄兔28只,其中7只做为假手术对照组(SOG),7只做为输精管结扎组(VG),14只为输精管吻合组(VAG)。16个月后,检测前列腺胞核雄激素受体的变化。结果是SOG、VG、VAG胞核雄激素受体的Kd值分别为4.81nmol/L,9.36nmol/L,5.67nmol/L;最大结合容量(fmol/mg DNA)为203.66,440.89,232.11,VG胞核雄激素受体Kd值及最大结合容量虽有升高,但VAG与SOG则呈一致的变化。单点分析三组的受体水平无显著差异(P>0.05)。说明,输精管结扎及吻合对前列腺胞核雄激素受体的水平无明显影响。     

血清脂蛋白胆固醇水平与HDL亚类组成的关系

目的探讨血清HDL—C、LDL—C水平对HDL亚类组成及含量的影响。方法采用双向电泳一免疫印迹检测法分析了292例受试者血清HDL亚类的组成及含量。结果随血清HDL—C水平逐渐降低，preβ1-HDL、HDL3b含量呈增加趋势，与高HDL—C组比较，低HDL—C组preβ1-HDL(P＜0．01)、HDL3b(P＜0．05)含量显著增加；相反，HDL2b、HDL2a含量呈减少趋势，与高HDL—C组比较，中HDL—C组及低HDL—C组HDL2b、HDL2a含量显著减少(P＜0．01)。随血清LDL-C水平逐渐升高，preβ1-HDL、HDL3c、HDL3b含量呈增加趋势，与正常LDL—C组比较，高LDL-C组(P＜0．05)和极高LDL-C组(P＜0．01)preβ1-HDL、HDL3b含量显著增加，极高LDL—C组HDL3c含量也显著增加(P＜0．01)；相反，HDL2b含量呈减少趋势，与正常LDL—C组比较，高LDL—C组(P＜0．05)和极高LDL—C组(P＜0．01)HDL2b含量显著减少。结论随血清HDL—C水平降低或LDL—C水平升高，均有小颗粒HDL含量增加及大颗粒HDL含量减少趋势，且血清HDL—C水平与大颗粒HDL2a、HDL2b含量的变化关系更为明显。     

马齿苋对家兔机体脂质与过氧化脂质含量的影响

对古老野菜马齿苋的抗氧化抗心血管疾病的作用进行实验研究。用野生马齿苋４ｇ／ｋｇ体重饲高膳食家兔，观察对家兔血脂，血粘度和脂类过氧化作用的影响。马齿苋能明显降低血清脂质和血沾度，对血浆中切表观粘度的降低尤为明显；能减少脂质过氧化，提高机体抗氧化酶的含量。     

大鼠肝实质及非实质细胞VLDL和HDL受体的研究

Saturable high-affinity VLDL and HDL receptor on parenchymal cells (PC), and non-parenchymal cells (NPC) freshly isolated from rat liver were studied. The VLDL- and HDL-receptor could mediate liver PC and NPC to bind, uptake, and degrade 125I-labeled human VLDL and apoE-deficient HDL3, and the activities of these two receptors (expressed as ng/mg cell protein) on NPC were about 10- and 4-fold higher than those on PC, respectively. VLDL receptor on NPC with kd 15.0-34.2 micrograms/ml and Bmax 2170-2607 ng/mg cell protein could be inhibited by EDTA, and down-regulated by cell cholesterol content. HDL receptor on NPC with kd 10.1-17.7 micrograms/ml and Bmax 1004-2738 ng/mg cell protein could not be inhibited by EDTA, but could be up-regulated by cell cholesterol content. Competitive inhibition assay showed that VLDL receptor could not only bind VLDL and LDL, but also bind HDL3 to some extent. Unlabeled purified apolipoprotein CIII-1, but apoAI, CI, CII, could effectively inhibit 125I-labeled VLDL binding to NPC. These results suggest that liver NPC may be more active than PC in clearing VLDL and HDL from circulation, and apolipoprotein CIII play an important inhibitory role in these receptor-mediated processes.