Valevski A, Modai I, Jerushalmy Z, Kikinzon L, Weizman A
Gehah Psychiatric Hospital, Petah-Tiqva, Israel.
Psychiatry Res. 1995 Jul 28;57(2):193-6. doi: 10.1016/0165-1781(95)02642-a.
Previous research has demonstrated that the circadian rhythm of melatonin negatively correlates with that of the sensitivity of platelet serotonin uptake sites. Moreover, serotonin has been found to be a competitive inhibitor of melatonin binding to platelets. The goal of the present study was to investigate whether melatonin directly affects platelet serotonin transport. Blood samples from 12 healthy subjects were assayed for both serotonin transport into platelets. Active transport of serotonin (at a concentration of 10(-6) M) into blood platelets was measured in the presence of melatonin at physiological concentrations (10(-12) M to 2 x 10(-9) M) and high nonphysiological concentrations (2 x 10(-8) M to 2 x 10(-3) M). Melatonin inhibited serotonin uptake by blood platelets at the high concentrations only ( > 10(-5) M with IC50 value of 1.1 x 10(-3) M) and had no effect at physiological concentrations.
先前的研究表明，褪黑素的昼夜节律与血小板5-羟色胺摄取位点的敏感性呈负相关。此外，已发现5-羟色胺是褪黑素与血小板结合的竞争性抑制剂。本研究的目的是调查褪黑素是否直接影响血小板5-羟色胺转运。对12名健康受试者的血样进行了5-羟色胺向血小板内转运的检测。在生理浓度（10(-12)M至2×10(-9)M）和高非生理浓度（2×10(-8)M至2×10(-3)M）的褪黑素存在下，测定了5-羟色胺（浓度为10(-6)M）向血小板的主动转运。褪黑素仅在高浓度（>10(-5)M，IC50值为1.1×10(-3)M）时抑制血小板对5-羟色胺的摄取，而在生理浓度下无作用。
