Hedberg P A, Rutlen D L
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
Acta Physiol Scand. 1990 Aug;139(4):561-8. doi: 10.1111/j.1748-1716.1990.tb08959.x.
The influence of serotonin on intravascular volume in the total capacitance circulation has not previously been examined. Thus, blood was drained from the venae cavae to an extracorporeal reservoir and returned to the right atrium at a constant rate so that total intravascular volume changes could be recorded as the inverse of changes in reservoir volume in 31 anaesthetized dogs. Serotonin (588 +/- 47 micrograms) in the left atrium was associated with an initial decrease in intravascular volume of 39 +/- 12 ml (P less than 0.01) followed by an increase of 129 +/- 31 ml (P less than 0.01) above control at 20 min. Mean arterial pressure increased from a control of 74 +/- 4 mmHg to 99 +/- 7 mmHg (P less than 0.01) initially and then decreased to 64 +/- 5 mmHg (P less than 0.05) at 20 min. Following ganglionic blockade with mecamylamine, serotonin caused only a decrease in intravascular volume, which was 73 +/- 12 ml (P less than 0.01) at 20 min. 5-HT2 and alpha-adrenergic blockade with ketanserin did not attenuate the early decrease in intravascular volume. 5-Carboxamidotryptamine (82 +/- 39 micrograms), a 5-HT1 agonist, was associated with only an increase in intravascular volume, which was 82 +/- 13 ml (P less than 0.01) at 20 min and which was abolished after ganglionic blockade. Thus, serotonin causes a biphasic change in total intravascular volume. The initial decrease in intravascular volume is not mediated by a reflex or by 5-HT1, 5-HT2, or alpha-adrenergic receptor stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
血清素对总容量循环中血管内容量的影响此前尚未得到研究。因此，将31只麻醉犬的腔静脉血液引流至体外储液器，并以恒定速率回输至右心房，以便将血管内容量的总体变化记录为储液器容量变化的倒数。左心房注入血清素（588±47微克）后，血管内容量最初减少39±12毫升（P<0.01），随后在20分钟时比对照组增加129±31毫升（P<0.01）。平均动脉压最初从对照组的74±4毫米汞柱升至99±7毫米汞柱（P<0.01），然后在20分钟时降至64±5毫米汞柱（P<0.05）。用美加明进行神经节阻断后，血清素仅引起血管内容量减少，在20分钟时减少73±12毫升（P<0.01）。用酮色林阻断5-HT2和α-肾上腺素能受体并未减弱血管内容量的早期减少。5-羧酰胺色胺（82±39微克），一种5-HT1激动剂，仅与血管内容量增加有关，在20分钟时增加82±13毫升（P<0.01），神经节阻断后这种增加消失。因此，血清素会引起血管内容量总量的双相变化。血管内容量的最初减少不是由反射或5-HT1、5-HT2或α-肾上腺素能受体刺激介导的。（摘要截短于250字）
