【摘要】 酪胺、利血平和胍乙啶减少組織內NA的机制不尽相同。本实驗比較苯乙肼对它們釋放大白鼠心脏NA的作用。心脏的NA用氧化鋁吸附分离后用大鼠血压法檢定。正常大白鼠心脏NA含量为0.93微克/克。每天腹腔注射苯乙肼20毫克/公斤,共3天,NA含量为1.26微克/克,有明显的增加。皮下注射酪胺20毫克/公斤后2小时,心脏NA含量减少为0.56微克/克;給苯乙肼3天后再給酪胺,NA量更减至0.39微克/克。腹腔注射利血平1毫克/公斤后5小时,心脏NA已几乎耗尽;給苯乙肼3天后再給同剂量的利血平,NA含量只减少一半左右;加大利血平剂量为2毫克/公斤,也仅能减低一半的量,至15小时已近耗尽。腹腔注射胍乙啶20毫克/公斤后5小时,NA已近耗尽;給苯乙肼3天后再注射胍乙啶20—100毫克/公斤,心脏NA未見减少。給苯乙肼3天后,腹腔注射胍乙啶,然后再給利血平或酪胺,NA减少一半。預先給利血平或胍乙啶,再給一次苯乙肼,胍乙啶的釋放作用完全被对抗,而利血平仍有耗尽心脏NA的作用。根据以上結果,苯乙肼似能加强酪胺釋放心脏NA的作用,能部分减少利血平对心脏,NA的耗尽作用,但可完全对抗胍乙啶的釋放作用。結合前文結果推論苯乙肼的抗交感作用是与影响NA的釋放有关。更多还原

【Abstract】 The mechanisms of depletion of the tissue noradrenaline （NA） by tyramine, reserpine and guanethidine are not entirely the same. The influences of phenelzine on the depletion of myocardial NA by these drugs were compared in rats. The NA was separated by Al₂O₃ adsorption and assayed on rat’s blood pressure. The average content of NA in normal rat heart was found to be 0.93μg/g. A daily intraperitoneal injection of phenelzine 20 mg/kg for 3 days raised the NA content up to 1.26μg/g. The increase was statistically significant. Subcutaneous injection of tyramine hydrochloride 20 mg/kg reduced in 2 hours the NA content to 0.56μg/g. If phenelzine was administered for 3 days prior to the tyramine injection, the NA content was further brought down to 0.39μg/g. Intraperitoneal injection of reserpine 1 mg/kg almost depleted the NA in 5 hours. But if the reserpine was given after pretreatment with phenelzine for 3 days, the myocardial NA was only half depleted. Increasing the dose of reserpine to 2 mg/kg diminished the NA content to one half in 5 hours, and yielded a near depletion in 15 hours. Intraperitoneal injection of guanethidine sulphate 20 mg/kg caused a well-nigh complete depletion in 5 hours. If guanethidine sulphate 20—100 mg/kg was given subsequent to a 3-day administration of phenelzine, the NA did not decrease. Subsequent to a 3-day administration of phenelzine, intraperitoneal injection of guanethidine and then injection of reserpine or tyramine decreased the NA amount to about 50％. If guanethidine or reserpine was given prior to phenelzine, the NA-depleting action of guanethidine was abolished, but that of reserpine persisted. The above results may be summarized by saying that the NA-releasing action of tyramine seemed to be augmented, that of reserpine was partly diminished and that of guanethidine was wholly antagonized by phenelzine. Referring to results reported previously^[7] it is inferred that the sympatholytic action of phenelzine may be related to interference with the release of NA.更多还原