Reiter Russel J, Tan Dan-Xian, Korkmaz Ahmet
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, USA.
J Hypertens Suppl. 2009 Aug;27(6):S17-20. doi: 10.1097/01.hjh.0000358832.41181.bf.
In experimental rodents, surgical removal of the pineal gland, the major source of circulating melatonin, causes a gradual and sustained rise in blood pressure. Conversely, when melatonin is chronically administered to pinealectomized rodents the increment in blood pressure is ameliorated. In humans as well, the night time rise in endogenous circulating melatonin levels may be inversely related to the reduction in night time blood pressure. Among patients with hypertension, some exhibit a much greater reduction in blood pressure at night (the so-called 'extreme dippers' and 'dippers'), whereas others exhibit only a slight night time reduction in systolic and diastolic pressure ('non-dippers' and 'inverted dippers'). Longitudinal studies of these patients show that inverted dippers and non-dippers die at a faster rate than do dippers and extreme dippers. The chronic administration of melatonin to individuals with hypertension induces a measurable drop in night time systolic and diastolic blood pressure. Moreover, the higher the night time level of endogenous melatonin (estimated from urinary metabolite of melatonin, 6-hydroxymelatonin sulphate), the greater the reduction in arterial blood pressure at night. The implication of these findings is that melatonin may have utility as an antihypertensive agent.
在实验啮齿动物中，切除作为循环褪黑素主要来源的松果体，会导致血压逐渐持续升高。相反，当对松果体切除的啮齿动物长期给予褪黑素时，血压的升高会得到改善。在人类中，内源性循环褪黑素水平的夜间升高可能与夜间血压降低呈负相关。在高血压患者中，一些患者夜间血压降低幅度更大（所谓的“极端杓型”和“杓型”），而另一些患者收缩压和舒张压仅在夜间有轻微降低（“非杓型”和“反杓型”）。对这些患者的纵向研究表明，反杓型和非杓型患者的死亡速度比杓型和极端杓型患者更快。对高血压患者长期给予褪黑素会使夜间收缩压和舒张压出现可测量的下降。此外，内源性褪黑素的夜间水平越高（根据褪黑素的尿代谢产物硫酸6-羟基褪黑素估计），夜间动脉血压的降低幅度就越大。这些发现表明褪黑素可能具有作为抗高血压药物的效用。
