Tosukhowong P, Chotigasatit C, Tungsanga K, Sriboonlue P, Pansin P, Sitprija V
Department of Biochemistry, Chulalongkorn University Hospital, Bangkok, Thailand.
Am J Nephrol. 1996;16(5):369-74. doi: 10.1159/000169027.
The sudden unexplained death syndrome (SUDS) is a sudden death of unknown cause in healthy South-East Asians. In Thailand, it is common in the North-East region. We previously reported high incidences of low erythrocyte sodium and potassium-activated adenosine triphosphatase (Na,K-ATPase) activity and of high erythrocyte sodium in North-East Thais and speculated that this metabolic defect might be associated with the high incidence of SUDS in that region. In this communication, we studied plasma sodium and potassium, erythrocyte sodium and potassium, activities of erythrocyte Na,K-ATPase, ouabain-insensitive ATPase and total ATPase in healthy Thai blood donors from Central Thailand (group 1), healthy North-East city dwellers (group 2), relatives of SUDS victims (group 3) and survivors from SUDS-like attacks (group 4). Compared with groups 1 and 2, group 3 and 4 subjects had significantly lower plasma potassium (p < 0.0001), higher erythrocyte sodium (p < 0.0001), lower activities of erythrocyte Na,K-ATPase (p < 0.0001) and of erythrocyte total ATPase (p < 0.0001). In addition, group 4 subjects had lower plasma potassium, higher erythrocyte sodium and lower activity of total ATPase than those of group 3. The findings suggest that the pathogenesis of SUDS could be related to hypokalemia and a membrane sodium/potassium pump defect.
不明原因猝死综合征（SUDS）是指健康东南亚人发生的不明原因猝死。在泰国，该综合征在东北地区较为常见。我们之前报道过，泰国东北部人群中红细胞钠钾激活的三磷酸腺苷酶（Na，K - ATP酶）活性低以及红细胞钠含量高的发生率很高，并推测这种代谢缺陷可能与该地区SUDS的高发病率有关。在本通讯中，我们研究了来自泰国中部的健康献血者（第1组）、健康的东北城市居民（第2组）、SUDS受害者的亲属（第3组）以及类似SUDS发作幸存者（第4组）的血浆钠和钾、红细胞钠和钾、红细胞Na，K - ATP酶、哇巴因不敏感ATP酶和总ATP酶的活性。与第1组和第2组相比，第3组和第4组受试者的血浆钾显著降低（p < 0.0001），红细胞钠升高（p < 0.0001），红细胞Na, K - ATP酶活性降低（p < 0.0001）以及红细胞总ATP酶活性降低（p < 0.0001）。此外，第4组受试者的血浆钾低于第3组，红细胞钠高于第3组，总ATP酶活性低于第3组。这些发现表明SUDS发病机制可能与低钾血症和膜钠/钾泵缺陷有关。
