Leonhardt A, Magsaam J, Goldner M, Kühl P G, Seyberth H W
Children's Hospitals, University of Marburg, Germany.
Eur J Clin Invest. 1996 Dec;26(12):1057-61. doi: 10.1046/j.1365-2362.1996.370590.x.
The high risk of vaso-occlusive events in children younger than 4 years with cyanotic congenital heart disease and polycythaemia has been attributed to increased thromboxane (Tx) A2 formation. In older children with cyanotic congenital heart disease, however, the risk of vaso-occlusive events is much lower. We therefore hypothesized that the formation of TxA2 and prostacyclin is not disturbed in this age group. We measured urinary excretion of stable index metabolites of in vivo TxA2 and prostacyclin formation by gas chromatography-mass spectrometry in nine children (age 5.9-14.4, median 8.7 years) with cyanotic congenital heart disease, and in nine healthy, age-matched control subjects. The patients excreted less 2,3-dinor-TxB2 (systemic TxA2 formation, P = 0.03), 2,3-dinor-6-keto-PGF1 alpha (systemic prostacyclin formation. P = 0.03) and TxB2 (renal TxA2 formation, P = 0.01) than the control subjects. We conclude that in children older than 5 years with cyanotic congenital heart disease, endogenous synthesis of TxA2 and prostacyclin is not stimulated. This result may explain the lower risk of vaso-occlusive events in this age group as compared with younger children. In addition, our results suggest that chronic hypoxaemia may affect the in vivo formation of TxA2 and prostacyclin and the metabolic disposition of TxB2.
患有青紫型先天性心脏病和红细胞增多症的4岁以下儿童发生血管闭塞性事件的高风险归因于血栓素（Tx）A2生成增加。然而，在患有青紫型先天性心脏病的大龄儿童中，血管闭塞性事件的风险要低得多。因此，我们推测在这个年龄组中TxA2和前列环素的生成并未受到干扰。我们通过气相色谱 - 质谱法测量了9名患有青紫型先天性心脏病的儿童（年龄5.9 - 14.4岁，中位数8.7岁）以及9名年龄匹配的健康对照受试者体内TxA2和前列环素生成的稳定指标代谢物的尿排泄量。与对照受试者相比，患者排泄的2,3 - 二去甲 - TxB2（全身TxA2生成，P = 0.03）、2,3 - 二去甲 - 6 - 酮 - PGF1α（全身前列环素生成，P = 0.03）和TxB2（肾脏TxA2生成，P = 0.01）较少。我们得出结论，在5岁以上患有青紫型先天性心脏病的儿童中，TxA2和前列环素的内源性合成未受到刺激。这一结果可能解释了与年幼儿童相比，该年龄组血管闭塞性事件风险较低的原因。此外，我们的结果表明慢性低氧血症可能影响TxA2和前列环素的体内生成以及TxB2的代谢处置。
