Kallio A, Scheinin M, Koulu M, Ponkilainen R, Ruskoaho H, Viinamäki O, Scheinin H
Department of Pharmacology, University of Turku, Finland.
Clin Pharmacol Ther. 1989 Jul;46(1):33-42. doi: 10.1038/clpt.1989.103.
Dexmedetomidine, a selective alpha 2-adrenoceptor agonist, was administered to five healthy male volunteers in single intravenous doses of 12.5, 25, 50, and 75 micrograms as part of a placebo-controlled study. The drug caused dose-dependent decreases in systolic and diastolic blood pressure. A small initial hypertensive response was observed after injection of the two highest doses. Heart rate was decreased. The concentration of norepinephrine in plasma was decreased significantly (by up to 92%), and the decrease was dose-dependent. No significant drug-induced alterations were observed in plasma renin activity or in the concentrations of atrial natriuretic peptide and arginine vasopressin in plasma. Other drug effects included dose-dependent impairment of vigilance and stimulation of growth hormone secretion. Plasma cortisol levels were unaffected. Dexmedetomidine is a potentially useful tool for studies of the physiology and pharmacology of alpha 2-adrenoceptors in human beings and may have therapeutic applications in clinical conditions in which sedative and sympatholytic effects are considered beneficial, such as premedication for anesthesia and surgery.
右美托咪定是一种选择性α2肾上腺素能受体激动剂，作为一项安慰剂对照研究的一部分，以单次静脉注射剂量12.5、25、50和75微克给予5名健康男性志愿者。该药物导致收缩压和舒张压呈剂量依赖性下降。注射两个最高剂量后观察到一个小的初始高血压反应。心率下降。血浆中去甲肾上腺素浓度显著降低（高达92%），且降低呈剂量依赖性。在血浆肾素活性或血浆中心房利钠肽和精氨酸加压素的浓度方面未观察到明显的药物诱导改变。其他药物作用包括剂量依赖性的警觉性损害和生长激素分泌刺激。血浆皮质醇水平未受影响。右美托咪定是研究人类α2肾上腺素能受体生理学和药理学的一种潜在有用工具，并且在镇静和抗交感神经作用被认为有益的临床情况中可能有治疗应用，如麻醉和手术的术前用药。
