Gewitz M H, Pitt B R, Laks H, Hammond G L, Talner N S, Gillis C N
Pediatr Pharmacol (New York). 1982;2(1):57-63.
Extraction of circulating vasoactive hormones by the lung may influence systemic vasomotor tone. Since this process occurs in the pulmonary microcirculation, we evaluated the effects of pulmonary artery hypertension (PAH) secondary to congenital heart disease (CHD) on this metabolic function of lung. Eleven patients with varying congenital cardiac lesions were studied preoperatively and postoperatively. Five had normal pulmonary artery pressure (PAP) (group I), and six had PAH with peak systolic PAP greater than 40 mm Hg (group II). PA and postpulmonary arterial blood samples were collected before and after surgery at the time of pressure measurements. Norepinephrine (NE) and epinephrine (EPI) levels were determined by radioenzymatic assay. Preoperatively, circulating NE levels were higher (P less than 0.05) and NE extraction measured was lower (P less than 0.01) in group II patients as compared with group I. Extraction increased in group II postoperatively after PA pressures were reduced, becoming equivalent to group I postoperative values. EPI extraction was negligible in either group at any time. These data demonstrate that lungs of children are capable of selective catecholamine uptake and that elevated PAP occuring with CHD is associated with a decrease in this capability and an increase in circulating NE levels. Additionally, the decrease in NE extraction observed with PAH is reversible once PAP is reduced by surgical repair of the cardiac defect.
肺对循环中血管活性激素的提取可能会影响全身血管运动张力。由于这一过程发生在肺微循环中，我们评估了先天性心脏病（CHD）继发的肺动脉高压（PAH）对肺这一代谢功能的影响。对11例患有不同先天性心脏病变的患者进行了术前和术后研究。5例患者肺动脉压（PAP）正常（I组），6例患者PAH，收缩压峰值大于40 mmHg（II组）。在手术前后压力测量时采集肺动脉和肺动脉后血样。通过放射酶法测定去甲肾上腺素（NE）和肾上腺素（EPI）水平。术前，与I组相比，II组患者循环NE水平较高（P<0.05），测得的NE提取率较低（P<0.01）。II组术后PA压力降低后提取率增加，与I组术后值相当。两组在任何时候EPI提取率都可忽略不计。这些数据表明，儿童的肺能够选择性摄取儿茶酚胺，并且CHD伴发的PAP升高与这种能力的降低以及循环NE水平的升高有关。此外，一旦通过心脏缺损的手术修复使PAP降低，PAH时观察到的NE提取率降低是可逆的。
