Rendu F, Nurden A T, Lebret M, Caen J P
J Lab Clin Med. 1981 May;97(5):689-99.
Platelets from patients with the BSS make an interesting model for the study of 5-HT uptake, with their abnormal morphology including a defect in the plasma membrane GP I sialoglycoproteins (GP lb and glycocalicin), increased density in relation to an increased DB content, and increased size as a result of an abnormal shape change. The "apparent" kinetics of 5-HT incorporation by BSS platelets as measured with [3H]5-HT (0.2 to 2 micro M) were greatly modified: the VM was increased, but a high KM was needed. With a 5-HT concentration corresponding to the control platelet KM, twice as much 5-HT storage was taken up by BSS platelets as by normal platelets. The BSS platelets capacity for 5-HT storage as measure with [14C]5-HT (3 to 54 micro M) was increased up to to fivefold but normally inhibited b reserpine. The metabolism of platelet 5-HT was neither more rapid nor increased. The results, which further define the BSS platelet abnormalities, strongly suggest (1) a modification of the 5-HT transport process at the plasma membrane level and (2) an increased capacity of the platelets to accumulate 5-HT due to the increased DB content that parallels the increased platelet size. The possible relation between these two phenomena is discussed.
患有血小板无力症（BSS）患者的血小板是研究5-羟色胺（5-HT）摄取的有趣模型，其形态异常，包括质膜糖蛋白I（GP I）唾液酸糖蛋白（GP lb和糖萼蛋白）缺陷、与致密体（DB）含量增加相关的密度增加以及由于异常形状变化导致的大小增加。用[3H]5-HT（0.2至2微摩尔）测量的BSS血小板摄取5-HT的“表观”动力学有很大改变：最大转运速率（VM）增加，但需要高的米氏常数（KM）。在对应于对照血小板KM的5-HT浓度下，BSS血小板摄取的5-HT储存量是正常血小板的两倍。用[14C]5-HT（3至54微摩尔）测量的BSS血小板储存5-HT的能力增加了五倍，但通常会被利血平抑制。血小板5-HT的代谢既没有加快也没有增加。这些进一步明确BSS血小板异常的结果强烈表明：（1）质膜水平上5-HT转运过程的改变；（2）由于与血小板大小增加平行的DB含量增加，血小板积累5-HT的能力增强。讨论了这两种现象之间可能的关系。
