弥漫性脑损伤微血管形态学研究

目的 运用形态计量学方法研究弥漫性脑损伤（DBI）大鼠模型的微循环及胶质细胞形态学改变,并观察萘呋胺酯（NF）对DBI的治疗作用。方法 采用Marmarou的DBI模型,光镜下测量顶叶皮质内微血管及其周围水肿区的截面面积,电镜下半定量测定皮质区毛细血管周的水肿范围及胶质细胞胞体的肿胀程度。结果 外伤后2、6、24小时平均微血管截面面积与对照组比较无显著缩小,6、24小时微血管周水肿明显增加。NF组伤后2小时微血管无扩张,但其周围水肿增加,24小时两者均改善。电镜下2、24小时毛细血管周水肿明显;胶质细胞胞体肿胀在2小时明显,24小时无显著差异;NF在2小时能减轻胶质细胞肿胀程度,但对毛细血管周水肿范围影响不大。结论 形态计量学方法能准确反映脑外伤后微循环及脑水肿改变。外伤早期慎用血管扩张药物。

Experimental study of microcircular morphological changes of diffuse brain injury

Objective To observe the morphological changes of microcirculation and astrocytes on diffuse brain injury (DBI) in rats by morphometric method, and examine the effects of naftidrofuryl(NF), a 5 HT 2 anagonist, on DBI. Methods Using Marmarous DBI rat model, the microvascular cross section area and perivascular edema area in parietal cortex were calculated under light microscope, the edema range of pericapillary and swelling extent of astrocytes were observed and semi quantitily measured under transmission electron microscope. Results Compared with control group, the average microvasculature cross section of DBI at 2, 6, 24hr after injury were reduced obviously and the average perivascular edema area at 6, 24hr after injury were increased markedly. Treated with NF, at 2hr after insult, there was no enlargement in the cross section of microvascular but the vasogenic edema were worsen, and at 24hr after insult. the dilatation of vessels and the brain edema were alleviated. Under TEM, the pericapillary edema could be observed at 2, 24hr after insult. Astrocytes were swelling at 2hr but recovered at 24hr, NF could alleviate astrcytic swelling but played no role in reducing edematous range of pericapillaries. Conclusions Morphometry could reflect correctly the changes of microcirculation and brain edema, The use of vasodilator should be cautious at early stage of head injury.