Majewski H, Tung L H, Rand M J
J Cardiovasc Pharmacol. 1982 Jan-Feb;4(1):99-106. doi: 10.1097/00005344-198201000-00016.
Rats implanted with osmotic minipumps containing adrenaline (0.2 ml, 2.9 mM) developed increased systolic and diastolic blood pressures, whereas blood pressures in rats implanted with osmotic minipumps containing the same amount of noradrenaline did not differ from those of sham-operated control rats. Heart rates did not differ from control in either treatment group. Concomitant administration of metoprolol (2.5 mg/kg, i.p., twice daily) abolished the effect of adrenaline-treatment on blood pressure. Plasma concentrations of adrenaline and noradrenaline released from the minipumps were 17 nM and 2.4 nM, respectively The atria accumulated 56 pmol/g of adrenaline released from the minipump. In isolated atria, adrenaline (10 nM) increased noradrenergic transmitter release by acting on prejunctional beta-adrenoceptors. Incubation of isolated atria with adrenaline led to the accumulation of 46 pmol/g. This adrenaline was released as a cotransmitter and mediated a positive feedback effect on transmission which was disrupted by metoprolol (0.1 micro M). It is suggested that the increase in blood pressure produced in rats by chronic treatment with adrenaline is due to facilitation of noradrenergic transmission to cardiovascular effector tissues. Such an effect may be involved in the development of stress-induced hypertension.
植入含有肾上腺素（0.2毫升，2.9毫摩尔）的渗透微型泵的大鼠，其收缩压和舒张压升高，而植入含有等量去甲肾上腺素的渗透微型泵的大鼠血压与假手术对照大鼠无异。两个治疗组的心率与对照组相比均无差异。同时给予美托洛尔（2.5毫克/千克，腹腔注射，每日两次）可消除肾上腺素治疗对血压的影响。微型泵释放的肾上腺素和去甲肾上腺素的血浆浓度分别为17纳摩尔和2.4纳摩尔。心房积累了从微型泵释放的56皮摩尔/克肾上腺素。在离体心房中，肾上腺素（10纳摩尔）通过作用于突触前β-肾上腺素能受体增加去甲肾上腺素能递质释放。用肾上腺素孵育离体心房导致积累46皮摩尔/克。这种肾上腺素作为共递质释放，并介导对传递的正反馈作用，该作用被美托洛尔（0.1微摩尔）破坏。提示慢性肾上腺素治疗使大鼠血压升高是由于促进了去甲肾上腺素能向心血管效应组织的传递。这种效应可能参与了应激性高血压的发生发展。
