Llanos A J, Seron-Ferre M, Ramachandran J, Creasy R K, Heymann M A, Rudolph A M
Pediatr Res. 1983 Nov;17(11):903-8. doi: 10.1203/00006450-198311000-00013.
To determine the effects of alpha-melanocyte stimulating hormone (alpha MSH) on the circulation of undisturbed fetal sheep and young lambs and to explore possible mechanisms of actions, we examined the responses of ascending aortic blood flow, heart rate, stroke volume, and arterial blood pressure to a single intravenous injection of alpha MSH, ACTH, cortisol and to alpha MSH after beta-adrenergic blockade. We also measured cardiac output and organ blood flows before and after alpha MSH injection by the radionuclide labeled microsphere technique. alpha MSH increased ascending aortic blood flow from 249 +/- 23 to 327 +/- 30 ml X min-1 X kg-1 (P less than 0.001), heart rate from 111 +/- 10 to 126 +/- 11 min-1, (P less than 0.001) and stroke volume from 2.32 +/- 0.21 to 2.75 +/- 0.20 ml X kg-1, (P less than 0.001) in 10 young lambs 15-30-day-old. alpha MSH decreased mean systemic arterial blood pressure from 42.6 +/- 1.7 to 39.3 +/- 1.6 mmHg (P less than 0.001) in fetal sheep and min-1, (P less than 0.001) and stroke volume from 2.32 +/- 0.21 to 2.75 +/- 0.20 ml X kg-1, (P less than 0.001) in 10 young lambs 15-30-days-old. alpha MSH decreased mean systemic arterial blood pressure from 42.6 +/- 1.7 to 39.3 +/- 1.6 mmHg (P less than 0.001) in fetal sheep and from 77.5 +/- 4.5 to 72.7 +/- 4.3 mmHg (P less than 0.001) in young lambs. In six additional young lambs (20-35-day-old) cardiac output, measured by microspheres, increased with alpha MSH from 216 +/- 20 to 261 +/- 19 ml X min-1 X kg-1 (P less than 0.001). alpha MSH also increased blood flow to the myocardium from 104 +/- 22 to 151 +/- 26 ml X min-1 X 100 g-1 (P less than 0.001), to the adrenals from 195 +/- 38 to 243 +/- 41 ml X min-1 X 100 g-1, (P less than 0.05), and to the lungs from 157 +/- 31 to 468 +/- 81 ml X min-1 X 100 g-1 (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
为了确定α-黑素细胞刺激素（αMSH）对未受干扰的胎羊和幼羊循环系统的影响，并探索其可能的作用机制，我们研究了单次静脉注射αMSH、促肾上腺皮质激素（ACTH）、皮质醇以及β-肾上腺素能阻断后注射αMSH时，升主动脉血流量、心率、每搏输出量和动脉血压的反应。我们还通过放射性核素标记微球技术测量了αMSH注射前后的心输出量和器官血流量。在10只15 - 30日龄的幼羊中，αMSH使升主动脉血流量从249±23增加至327±30 ml·min⁻¹·kg⁻¹（P<0.001），心率从111±10增加至126±11次/分钟（P<0.001），每搏输出量从2.32±0.21增加至2.75±0.20 ml·kg⁻¹（P<0.001）。αMSH使胎羊的平均体循环动脉血压从42.6±1.7降至39.3±1.6 mmHg（P<0.001），使幼羊的平均体循环动脉血压从77.5±4.5降至72.7±4.3 mmHg（P<0.001）。在另外6只20 - 35日龄的幼羊中，通过微球测量的心输出量随着αMSH从216±20增加至261±19 ml·min⁻¹·kg⁻¹（P<0.001）。αMSH还使心肌血流量从104±22增加至151±26 ml·min⁻¹·100 g⁻¹（P<0.001），肾上腺血流量从195±38增加至243±41 ml·min⁻¹·100 g⁻¹（P<0.05），肺血流量从157±31增加至468±81 ml·min⁻¹·100 g⁻¹（P<0.005）。（摘要截断于250字）
