Belik J, Stephens N L
Department of Pediatrics, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
J Appl Physiol (1985). 1993 Feb;74(2):682-7. doi: 10.1152/jappl.1993.74.2.682.
To evaluate the maturational changes in vascular muscle mechanics we studied and compared the isotonic half-time relaxation (t1/2P,CE) and maximal load-bearing capacity normalized to stress of pulmonary and systemic arterial muscle from perinatal and adult sheep. For the pulmonary and systemic vessels t1/2P,CE was significantly shorter in adult than in perinatal sheep (P < 0.01). In newborns t1/2P,CE of the pulmonary vessels was 185 +/- 31 (SE) s, longer than that of the systemic vessels (64 +/- 10 s; P < 0.01). In adults t1/2P,CE of the pulmonary vessels (101 +/- 14 s) was longer than that of the systemic vessels (37 +/- 5 s; P < 0.01). Maximal load-bearing capacities normalized to stress of pulmonary vessels of fetal and newborn sheep were twofold greater than those of adult sheep and of the systemic vessels of newborns and adults (P < 0.01). In conclusion, significant maturational changes in the isotonic and isometric mechanical properties of vascular pulmonary and systemic smooth muscle were observed in sheep.
为评估血管肌肉力学的成熟变化，我们研究并比较了围产期和成年绵羊肺和体循环动脉肌肉的等张半程松弛时间（t1/2P,CE）以及以应力归一化的最大承载能力。对于肺血管和体循环血管，成年绵羊的t1/2P,CE显著短于围产期绵羊（P < 0.01）。在新生羊中，肺血管的t1/2P,CE为185±31（SE）秒，长于体循环血管（64±10秒；P < 0.01）。在成年羊中，肺血管的t1/2P,CE（101±14秒）长于体循环血管（37±5秒；P < 0.01）。胎儿和新生羊肺血管以应力归一化的最大承载能力比成年羊以及新生和成年羊的体循环血管大两倍（P < 0.01）。总之，在绵羊中观察到肺和体循环血管平滑肌的等张和等长力学特性有显著的成熟变化。
