Oxygen distributions within R3230Ac tumors growing in dorsal flap window chambers in rats.
Oxygen distributions within R3230Ac tumors growing in dorsal flap window chambers in rats.
复制标题
大鼠背侧皮瓣窗室内生长的 R3230Ac 肿瘤内的氧分布。
DOI：
10.1007/978-1-4615-4863-8_71
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发表时间：
1998
影响因子：
--
通讯作者：
Dewhirst,MW
中科院分区：
文献类型：
--
作者：
Wilson,DF;Evans,SM;Jenkins,WT;Vinogradov,SA;Ong,E;Dewhirst,MW
R3230Ac乳腺肿瘤种植在250g Fischer 344大鼠背侧皮瓣内的透明窗腔中(见DeWhirst等，1992)。尾静脉注射氧磷R2(7 mg，0.3ml)后，用氧依赖的磷光猝灭法(见Vinogradov等人，1996)测量肿瘤和宿主组织的氧压分布。氧压图显示R3230Ac肿瘤相对于周围组织是低氧的。荧光粉的激发光谱在419 nm(蓝光)和524 nm(绿光)处有峰值，发射的磷光光谱和寿命与激发荧光粉的波长无关。由于细胞色素、血红蛋白、肌红蛋白等固有的发色团，组织对蓝光的吸收比绿光大得多。因此，蓝色激发测量比绿色激发更薄、更浅的表层(<；50微米)的氧分压，从而允许组织氧合的“光学切片”。通过从窗口的两侧进行测量，可以进一步对组织进行光学切片。从肿瘤方面看，这些肿瘤的浅层(蓝色激发)是低氧的，而宿主组织氧合良好。肿瘤生长边缘的氧分压低于肿瘤中心的氧分压，远低于宿主组织的氧分压。这一结果与DeWhirst和他的同事(1992)报道的微氧电极测量血管周围氧压的结果是一致的。
R3230Ac mammary tumors were grown in transparent window chambers implanted into the dorsal skin flap of 250 g Fischer 344 rats (see Dewhirst et al, 1992). The oxygen pressure distributions in the tumor and host tissue were measured by the oxygen dependent quenching of phosphorescence (see Vinogradov et al, 1996) after injection of Oxyphor R2 (7 mg, 0.3 ml) into the tail vein. The oxygen pressure maps show the R3230Ac tumors to be hypoxic relative to the surrounding tissue. The excitation spectrum for the phosphor has peaks at 419 nm (blue light) and at 524 nm (green light), and the emitted phosphorescence spectrum and lifetime are independent of the wavelength at which the phosphor is excited. The absorption by tissue is much greater for blue light than green light, due to intrinsic chromophores such as cytochromes, hemoglobin, myoglobin etc. Thus, blue excitation measures the oxygen pressures in a much thinner, superficial, surface layer (< 50 microns) than does green excitation, allowing “optical sectioning” of tissue oxygenation. The tissue can be further optically sectioned by making measurements from both sides of the window. Viewed from the tumor side, the superficial layers (blue excitation) of these tumors were hypoxic whereas the host tissue was well oxygenated. The oxygen pressures in the growing edge of the tumors are lower than those in the central core of the tumor, and much lower than those of the host tissue. This result is in agreement with the micro-oxygen electrode measurements of perivascular oxygen pressures reported by Dewhirst and coworkers (1992).