In 1994 , li et al isolated agmatine from cow brain . like clonidine , agmatine is an endogenous agonist at imidazoline receptors ( ir ) and a noncatecholamine ligand at ( ai - adrenergic receptors ( ( x2 - ar ) 胍丁胺( agmatine )是1994年li等从牛脑中分离纯化的一种内源性可乐定置换物质( clonidinedisplacingsubstance ， cds ) ，它可能作为一种新型的神经递质或调质。
Other less frequent occurrences with administration of alpha 2 agonists include bradycardia and sinoauricular block , which hae been suggested to occur more commonly in young patients due to their high leel of parasympathetic tone ( 5 ) 给与- 2受体激动剂后较少出现的作用包括心动过缓和窦房性传导阻滞，这些作用更常发生在年轻人，因为其副交感神经张力处于高水平[ 5 ] 。
Epinephrine is the mainstay of anaphylaxis therapy . adjunctive therapy with antihistamines and , for those with asthma , inhaled selective ? 2 - adrenergic agonists , such as albuterol , may be helpful but cannot replace epinephrine 肾上腺素是治疗速发型过敏反应的主要药物，抗组胺药及吸入选择性? 2肾上腺能阻滞剂（如沙丁胺醇）治疗哮喘等辅助治疗对患者有益但不能取代肾上腺素。
Several trials have been done to assess treatment of premenopausal breast cancer with luteinising - hormone - releasing hormone ( lhrh ) agonists , but results have been inconclusive , especially for patients with hormone - receptor - positive cancer 数项实验已被开展用于评估黄体生成素释放激素（ lhrh ）激动剂对绝经前乳腺癌患者的治疗效果，但结果并不确定，尤其是对那些激素受体阳性的癌症患者。
Results of 31 case patients with newly diagnosed cardiac - valve regurgitation , 6 were currently exposed to pergolide , 6 were currently exposed to cabergoline , and 19 had not been exposed to any dopamine agonist within the previous year 结果：有31例患者出现新诊断的心脏瓣膜返流，其中6例研究时正在服用培高利特， 6例使用卡麦角林，另外19例在研究的前一年中未再使用任何多巴胺受体激动剂。
In these two studies by the same japanese group ( 7 , 8 ) , the enhanced pressor effects of ephedrine and phenylephrine following an alpha 2 agonist ( clonidine ) were no different between awake and anesthetized ( enflurane and nitrous oxide in oxygen ) patients 在这两个研究中[ 7 ， 8 ] ，麻黄素和苯肾上腺素在使用- 2受体激动剂（可乐定）后的升压效果增强在清醒和麻醉（安氟醚和笑气）病人没有差别。
Conclusions the frequency of clinically important valve regurgitation was significantly increased in patients taking pergolide or cabergoline , but not in patients taking non ? ergot - derived dopamine agonists , as compared with control subjects 结论：与对照组相比，服用培高利特或者卡麦角林的患者临床上发生重要瓣膜返流的频率显著增加，但服用非麦角?生的多巴胺受体激动剂的患者瓣膜返流的发生率却未增加。
Ephedrine and phenylephrine can treat the hypotension , howeer an amplified asoconstrictie response may be obsered due to an alpha 2 agonist induced enhancement of baroreceptor reflexes ( 7 ) and potentiation of alpha 1 - adrenoceptor - mediated asoconstriction 麻黄素和苯肾上腺素可治疗低血压，然而可以观察到存在过度缩血管反应，因为- 2受体激动剂导致压力感受器反射[ 7 ]和- 1肾上腺素受体介导的血管收缩作用增强[ 8 ] 。
