Davis M J, Gilmore J P, Joyner W L
Circ Res. 1981 Jul;49(1):133-40. doi: 10.1161/01.res.49.1.133.
The responses to changes in transmural pressure were investigated in pulmonary allograft and cheek pouch arterioles in two oxygen environments. Neonatal hamster lung tissue was transplanted into adult hamster cheek pouches. After vascularization (8-10 days), pulmonary and cheek pouch vessels were observed by intravital microscopy in hamsters anesthetized with pentobarbital. By gassing the suffusion solution (bicarbonate-buffered Ringer's) (pH 7.4 at 35-37 degrees C) with either low oxygen (95% N2/5% CO2) or high oxygen (75% N2/5% CO2/20% O2) and after sealing the top of the chamber, extravascular pressure was altered by varying the fluid volume of the closed chamber. Changes in arteriolar diameters in response to positive and negative square-wave pressure pulses were quantified using a video micrometer and close-circuit TV system. Pulmonary arterioles showed a passive dilation or constriction in response to increases or decreases in transmural pressure (+/-20 mm Hg). These responses were not altered either by changes in PO2 or nitroprusside. In contrast, cheek pouch arterioles showed myogenic responses by constricting when transmural pressure was increased and vice versa. These responses were potentiated at high PO2 and abolished with nitroprusside. It is concluded that a myogenic response is dominant in cheek pouch arterioles but not in pulmonary arterioles under these conditions. These latter observations are consistent with results obtained from isolated, intact lung.
在两种氧环境下，研究了同种异体肺移植组织和颊囊小动脉对跨壁压力变化的反应。将新生仓鼠肺组织移植到成年仓鼠的颊囊中。血管化后（8 - 10天），在用戊巴比妥麻醉的仓鼠中，通过活体显微镜观察肺和颊囊血管。通过用低氧（95% N₂/5% CO₂）或高氧（75% N₂/5% CO₂/20% O₂）对灌注溶液（碳酸氢盐缓冲林格氏液，35 - 37℃时pH 7.4）进行通气，并在密封腔室顶部后，通过改变封闭腔室的液体体积来改变血管外压力。使用视频测微计和闭路电视系统对小动脉直径对正负方波压力脉冲的变化进行量化。肺小动脉对跨壁压力的增加或减少（±20 mmHg）表现出被动扩张或收缩。这些反应不会因PO₂或硝普钠的变化而改变。相比之下，颊囊小动脉在跨壁压力增加时会收缩，反之亦然，表现出肌源性反应。这些反应在高PO₂时增强，并用硝普钠消除。得出的结论是，在这些条件下，肌源性反应在颊囊小动脉中占主导地位，而在肺小动脉中则不然。这些后一项观察结果与从离体完整肺获得的结果一致。
