Davies P, Maddalo F, Reid L
J Appl Physiol (1985). 1985 Mar;58(3):795-801. doi: 10.1152/jappl.1985.58.3.795.
The reactivity of lung microvessels is determined by a method based on planimetry of elastic laminae (EL) in vessel cross sections. Because wall structure is assessed, arteries that undergo remodeling during chronic hypertension can be identified. To study the structure and reactivity of such vessels, slices obtained from lungs of six rats exposed to hypobaric hypoxia for 14 days and from normoxic controls were incubated in culture with 10(-4) M l-epinephrine (EPI), then fixed and processed for microscopy. For muscular arteries (less than 200 microns diam), the circumferential length of internal EL (IEL) is positively correlated with length of external EL (EEL). In larger arteries, EEL is shorter than IEL and may restrict distension, but in smaller arteries the converse is true. After chronic hypoxia, the regression line shifts, indicating structural remodeling. For newly muscularized arteries found only after hypoxia the new IEL is always shorter than EEL, and a complex network of elastin connects the two. Muscular arteries constrict with EPI to the same degree after hypoxia as after normoxia. Nonmuscular vessels (arteries and veins) also constrict similarly after either exposure regimen. For newly muscularized arteries of the same size and location as the nonmuscular vessels, the response is significantly less.
肺微血管的反应性通过一种基于血管横截面弹性膜（EL）平面测量法来确定。由于评估了血管壁结构，因此可以识别出在慢性高血压期间发生重塑的动脉。为了研究此类血管的结构和反应性，将从暴露于低压缺氧环境14天的6只大鼠的肺以及常氧对照大鼠的肺中获取的切片，在含有10^(-4) M l-肾上腺素（EPI）的培养基中孵育，然后固定并进行显微镜处理。对于肌性动脉（直径小于200微米），内部弹性膜（IEL）的圆周长度与外部弹性膜（EEL）的长度呈正相关。在较大的动脉中，EEL比IEL短，可能会限制扩张，但在较小的动脉中情况则相反。慢性缺氧后，回归线发生偏移，表明结构重塑。对于仅在缺氧后才出现的新肌性化动脉，新的IEL总是比EEL短，并且有一个复杂的弹性蛋白网络连接两者。缺氧后肌性动脉对EPI的收缩程度与常氧后相同。非肌性血管（动脉和静脉）在任何一种暴露方案后也有类似的收缩。对于与非肌性血管大小和位置相同的新肌性化动脉，其反应明显较小。
