CITRATE AND CALCIUM EFFECTS ON TAMM-HORSFALL GLYCOPROTEIN AS A MODIFIER OF CALCIUM-OXALATE CRYSTAL AGGREGATION
CITRATE AND CALCIUM EFFECTS ON TAMM-HORSFALL GLYCOPROTEIN AS A MODIFIER OF CALCIUM-OXALATE CRYSTAL AGGREGATION
复制标题
DOI：
10.1152/ajprenal.1993.265.6.f784
复制
发表时间：
1993-12-01
影响因子：
--
通讯作者：
JAEGER, P
中科院分区：
文献类型：
--
作者：
HESS, B;ZIPPERLE, L;JAEGER, P
在pH 5.7和200 mM NaCl条件下，测定了Tamm-Horsfall糖蛋白（THP）对草酸钙一水合物（COM）晶体聚集（A(c)）和THP特性粘度（V(i)）的影响，并研究了钙和柠檬酸盐对这些参数的影响。从7名男性复发性钙石形成者（RCSF）和8名年龄匹配的男性健康志愿者（N，正常）的24小时尿液中分离THP。在基础条件下，RCSF-THP对A(c)的抑制作用为28 +/- 10%，对正常THP的抑制作用为60 +/- 6% （P = 0.028）。在钙存在的情况下。THP浓度从16 mg/l增加到28 mg/l和40 mg/l逐渐降低RCSF-THP的抑制作用，但对N-THP不起作用。在40 mg/l时，N-THP的抑制作用为27 +/- 9%，RCSF-THP的抑制作用为-43 +/- 8% (P = 0.001)，即所有原THP均促进A(c)。在添加3.5 mM柠檬酸盐的情况下，正常人对A(c)的抑制作用为56 +/- 5%，石原THP对A(c)的抑制作用为34 +/- 6% (P = 0.021)， 7种石原THP对A(c)均有抑制作用。基础条件下RCSF-THP的V(i)高于N（162 +/- 21比93 +/- 15 ml/g， P = 0.021）和5 mM钙（352 +/- 54比118 +/- 17 ml/g， P = 0.001），即RCSF-THP更自聚集，但添加柠檬酸盐（185 +/- 29比123 +/- 19 ml/g）时，RCSF-THP不具有自聚集性。发现A(c)与V(i)呈负相关（r = -0.948, P = 0.0001），即自聚集较多的THP分子是A(c)较弱的抑制剂（甚至是启动子）。这些发现为柠檬酸盐在草酸钙a (c)中的作用提供了可能的新解释。
We measured the effects of Tamm-Horsfall glycoprotein (THP) on calcium oxalate monohydrate (COM) crystal aggregation (A(c)) in vitro as well as intrinsic viscosities (V(i) of THP at pH 5.7 and 200 mM NaCl and studied the effects of calcium and citrate on these parameters. THP were isolated from 24-h urines of seven male recurrent calcium stone formers (RCSF) and eight age-matched male healthy volunteers (N, normal). At basal conditions, RCSF-THP inhibited A(c) by 28 +/- 10% and normal THP by 60 +/- 6% (P = 0.028). In the presence of calcium. increasing THP concentrations from 16 to 28 and 40 mg/l progressively lowered inhibition by RCSF-THP, but not by N-THP. At 40 mg/l, inhibition by N-THP was 27 +/- 9% vs. -43 +/- 8% by RCSF-THP (P = 0.001), i.e., all stone former THP promoted A(c). With an additional 3.5 mM of citrate, inhibition of A(c) was 56 +/- 5% by normal and 34 +/- 6% by stone former THP (P = 0.021), and all seven stone former THP again inhibited A(c). V(i) of RCSF-THP was higher than that of N at basal conditions (162 +/- 21 vs. 93 +/- 15 ml/g, P = 0.021) and in the presence of 5 mM calcium (352 +/- 54 vs. 118 +/- 17 ml/g, P = 0.001), i.e., RCSF-THP were more self-aggregated, but not when citrate was added (185 +/- 29 vs. 123 +/- 19 ml/g). An inverse correlation between A(c) and V(i) (r = -0.948, P = 0.0001) was found, i.e., more self-aggregated THP molecules were weaker inhibitors (or even promoters) of A(c). These findings offer a possible new explanation for the role of citrate in calcium oxalate A(c).