Deng Y, Copeman L, Kaufman S
Department of Medicine, University of Alberta, Edmonton, Canada.
Life Sci. 1995;57(18):1647-53. doi: 10.1016/0024-3205(95)02144-8.
Previous experiments have shown that the reduction in plasma volume observed after administration of atrial natriuretic factor is abolished by splenectomy. In order to determine whether the spleen contains a factor that influences cardiorenal homeostasis, rat spleens were homogenized in phosphate-buffered saline, centrifuged, subjected to ultrafiltration (molecular weight cut-off 10,000), extracted on C18 affinity columns and dried. After reconstitution in isotonic saline, the extract was injected i.v. into conscious rats. In response to this extract, there was a dose-dependent diuresis, natriuresis, kaliuresis and chloruresis which plateaued during the second and third hours following administration. Solute-free water clearance was inversely related to urine output. Blood pressure fell significantly from 109 +/- 3 mm Hg to 103 +/- 3 mm Hg during the first 10 min. after injection of the extract, and tended to remain depressed thereafter. There was no accompanying increase in heart rate. We conclude that the mammalian spleen contains a natriuretic, hypotensive factor that may play a role in cardiorenal homeostasis.
先前的实验表明，给予心钠素后所观察到的血浆量减少在脾切除术后可消除。为了确定脾脏是否含有影响心肾稳态的因子，将大鼠脾脏在磷酸盐缓冲盐水中匀浆，离心，进行超滤（截留分子量10,000），在C18亲和柱上萃取并干燥。在等渗盐水中复溶后，将提取物静脉注射到清醒大鼠体内。对该提取物的反应是，出现了剂量依赖性的利尿、利钠、利钾和利氯作用，在给药后的第二和第三小时达到平稳。无溶质水清除率与尿量呈负相关。注射提取物后的最初10分钟内，血压从109±3 mmHg显著降至103±3 mmHg，此后趋于保持在较低水平。心率没有随之增加。我们得出结论，哺乳动物的脾脏含有一种利钠、降压因子，可能在心肾稳态中发挥作用。
