Effect of oncotic pressure on apolipoprotein A-I metabolism in the rat.
Effect of oncotic pressure on apolipoprotein A-I metabolism in the rat.
复制标题
胶体渗透压对大鼠载脂蛋白 A-I 代谢的影响。
DOI：
10.1016/0272-6386(95)90172-8
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Joles,JA
中科院分区：
文献类型：
--
作者：
Kaysen,GA;Hoye,E;JonesJr,H;vanTol,A;Joles,JA
肾病综合征的特征是血浆白蛋白和胶体渗透压降低，尿蛋白丢失和高脂血症。高密度脂蛋白(高密度脂蛋白)以及高密度脂蛋白中主要载脂蛋白apo A-I的水平在肾病大鼠和遗传性血清白蛋白血症(NAR)大鼠中升高，这些动物几乎没有血浆白蛋白，血浆pI降低，但没有蛋白尿，这表明尿蛋白丢失不是血浆apo A-I水平升高的原因。我们进行了这些研究，以确定肾病综合征和NAR患者血浆载脂蛋白A-I水平升高的机制，并确定血浆PI降低或白蛋白是否导致载脂蛋白A-I升高。我们首先测定了NAR和被动型Heymann肾炎(HN)大鼠与正常SD大鼠(SD)125I apo A-I高密度脂蛋白(HDLc)的清除量。HN(7.40+/-2.18%血浆池/小时)和NAR(5.63+/-1.12)组载脂蛋白A-I清除率和载脂蛋白A-I转换率(FTR)均显著低于SD组(9.87+/-0.75)。HN(487+/-127微克/100g体重/小时)和NAR(253+/-16)的载脂蛋白A-I总周转率(稳态时等于apo A-I合成速率)也显著高于SD(216+/-19)。因此，HN和NAR的载脂蛋白A-I分解代谢减少和合成增加均导致载脂蛋白A-I水平升高。然后，我们给另外两组人血清白蛋白或Ficoll输注f3p4人血清白蛋白或Ficoll，数量足以将血浆pi维持在正常范围内。
The nephrotic syndrome is characterized by reduced plasma albumin and colloid osmotic pressure (pi), urinary protein loss and hyperlipidemia. High-density lipoprotein (HDL) and the level of apo A-I, the principal apolipoprotein in HDL, is increased in nephrotic rats and rats with hereditary analbuminemia (NAR)--animals with virtually no albumin in plasma and reduced plasma pi, but without proteinuria, suggesting that urinary protein loss is not responsible for increased plasma apo A-I levels. We conducted these studies to determine the mechanism responsible for increased plasma apo A-I levels in the nephrotic syndrome and NAR and to determine whether reduced plasma pi or albumin was responsible for increased apo A-I. We first measured the clearance of 125I apo A-I HDL in NAR and rats with passive Heymann nephritis (HN) compared with normal Sprague Dawley (SD) control. Both the clearance of apo A-I and fractional apo A-I turnover rate (FTR) were significantly reduced both in HN (7.40 +/- 2.18% plasma pool/hr) and NAR (5.63 +/- 1.12) compared with SD (9.87 +/- 0.75). Total apo A-I turnover rate, which in steady state equals apo A-I synthesis rate, was also significantly increased in both HN (487 +/- 127 micrograms/100 g body weight/hr) and NAR (253 +/- 16), compared with SD (216 +/- 19). Thus decreased apo A-I catabolism and increased synthesis both contributed to increased apo A-I levels in HN and NAR. We then infused either f3p4roncotic human albumin or ficoll into two additional groups of HN for days in quantities sufficient to maintain plasma pi within the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)