Kristensen C G, Nakagawa Y, Coe F L, Lindheimer M D
Am J Physiol. 1986 Apr;250(4 Pt 2):R589-94. doi: 10.1152/ajpregu.1986.250.4.R589.
Protocols were designed to 1) identify atrial natriuretic factor (ANF) bioactivity in pregnant rats, 2) compare ANF activity in atria from gravid and virgin Sprague-Dawley animals, and 3) assess renal and vascular responsiveness to ANF during gestation. Similar quantities of ANF were extracted from atria of term gravid and age-matched controls (assayed as the natriuretic response in awake virgins). We then purified by high-performance liquid chromatography a peptide identical to the synthetic 23 amino acid atriopeptin II (AP II). With equimolar injections of ANF, gravid rats had a blunted natriuretic response (P less than 0.05). However, when dose was based on estimated extracellular volume, awake virgin and pregnant animals displayed similar highly significant dose-response curves to infused AP II (R's 0.8). When hydropenic rats were assayed, both gravid and virgins required 10 times more ANF to initiate a diuresis; dose-response curves again being similar and highly significant. Decrements in blood pressure were also similar in pregnant and nongravid animals. Thus, despite an increased intravascular volume of 70% during gestation, cardiac content of ANF and the renal and vascular responsiveness to this peptide are similar to those in virgin rats, suggesting resetting of ANF-volume relationships during pregnancy.
1）鉴定妊娠大鼠心房利钠因子（ANF）的生物活性；2）比较妊娠和未孕的Sprague-Dawley动物心房中的ANF活性；3）评估妊娠期肾脏和血管对ANF的反应性。从足月妊娠大鼠和年龄匹配的对照动物的心房中提取了相似量的ANF（以清醒未孕大鼠的利钠反应进行测定）。然后通过高效液相色谱法纯化出一种与合成的23个氨基酸的心房肽II（AP II）相同的肽。给予等摩尔的ANF注射时，妊娠大鼠的利钠反应减弱（P<0.05）。然而，当根据估计的细胞外液量调整剂量时，清醒的未孕和妊娠动物对注入的AP II显示出相似的高度显著的剂量反应曲线（相关系数R为0.8）。对限水大鼠进行测定时，妊娠和未孕大鼠启动利尿所需的ANF量均增加10倍；剂量反应曲线再次相似且高度显著。妊娠和未孕动物的血压下降情况也相似。因此，尽管妊娠期血管内容量增加了70%，但心脏中ANF的含量以及肾脏和血管对该肽的反应性与未孕大鼠相似，提示妊娠期ANF与容量的关系发生了重新调整。
