Lindqvist M, Kahan T, Melcher A, Bie P, Hjemdahl P
Division of Clinical Physiology, Danderyd Hospital, Karolinska Institute, Denmark.
Am J Physiol. 1996 Mar;270(3 Pt 1):E393-9. doi: 10.1152/ajpendo.1996.270.3.E393.
The contribution of epinephrine (Epi) to forearm vasodilator responses to mental stress was evaluated in 12 healthy men by comparing hemodynamic and plasma catecholamine responses to mental stress and to intravenous and intra-arterial infusions of epinephrine. Mental stress decreased forearm vascular resistance (FVR) by 45%, increased arterial Epi from 0.23 to 0.44 nmol/l in arterial plasma, and increased forearm norepinephrine overflow. Intra-arterial Epi infusion decreased FVR concentration dependently by up to 43%. Intravenous Epi infusion decreased diastolic arterial pressure and increased heart rate and systolic blood pressure dose dependently. FVR decreased by up to 39% at 4.60 nmol/l Epi in arterial plasma. The average Epi contribution to forearm vasodilation during mental stress was calculated to be between 9 and 30%, depending on if responses to stress were compared with intravenous or intra-arterial Epi infusion. Arterial atrial natriuretic peptide immunoreactivity increased by 23% during stress, supporting a vasodilator influence, whereas vasopressin immunoreactivity was unaffected. Thus secretion of Epi explains only part of the stress-induced forearm vasodilation. Intravenous infusion of Epi appears to activate sympathetic counterregulation.
通过比较对精神应激以及静脉和动脉内输注肾上腺素时的血流动力学和血浆儿茶酚胺反应，在12名健康男性中评估了肾上腺素（Epi）对前臂血管舒张反应的作用。精神应激使前臂血管阻力（FVR）降低45%，使动脉血浆中的动脉Epi从0.23纳摩尔/升增至0.44纳摩尔/升，并使前臂去甲肾上腺素溢出增加。动脉内输注Epi可使FVR浓度依赖性降低达43%。静脉输注Epi可使舒张压降低，并使心率和收缩压剂量依赖性增加。在动脉血浆中Epi为4.60纳摩尔/升时，FVR降低达39%。根据应激反应与静脉或动脉内输注Epi的反应进行比较，计算出精神应激期间Epi对前臂血管舒张的平均作用在9%至30%之间。应激期间动脉心房利钠肽免疫反应性增加23%，支持血管舒张作用，而加压素免疫反应性未受影响。因此，Epi的分泌仅解释了应激诱导的前臂血管舒张的一部分。静脉输注Epi似乎激活了交感神经的反调节作用。
