论文部分内容阅读
目的探讨小鼠血脑屏障(BBB)的发育特点。方法取出生第1天、第14天、第28天、第42天各2只昆明小鼠脑组织顶叶,切成1 mm×1 mm×1 mm小块,30 mL.L-1戊二醛和15 g.L-1多聚甲醛前固定,10 mL.L-1锇酸和15 mL.L-1亚铁氰化钾后固定,乙醇、丙酮脱水,环氧树脂618包埋剂包埋;超薄切片,醋酸铀、柠檬酸铅染色,在日立Hu-12A型透射电镜下观察出生后不同天数小鼠BBB的生长发育特点。结果出生第1天、第14天、第28天、第42天昆明小鼠BBB的脑毛细血管内皮、内皮细胞间的紧密连接、基膜、星形胶质细胞突起(胶质膜)等超微结构呈现明显差异。出生第1天脑组织内微血管壁厚,未见完整基膜,仅见到围绕毛细血管周围,呈不连续性、厚度和电子密度不均的基膜样物质,神经元及胶质细胞胞体靠近内皮细胞;随着生长发育,出生第14天、第28天昆明小鼠微血管壁变薄,基膜逐渐清晰完整;至出生第42天,昆明小鼠BBB进一步发育,基膜厚且密度高,神经元及胶质细胞胞体远离血管。结论新生小鼠BBB未发育成熟,是易发脑损伤的一个关键环节。
Objective To investigate the developmental characteristics of the blood-brain barrier (BBB) in mice. Methods The parietal lobe of 2 Kunming mice were sacrificed on day 1, day 14, day 28, and day 42, cut into small pieces of 1 mm × 1 mm × 1 mm and 30 mL.L-1 pentylenediamine Aldehyde and 15 gL-1 paraformaldehyde, fixed with 10 mL.L-1 osmium tetroxide and 15 mL.L-1 potassium ferrocyanide, dehydrated with ethanol and acetone, embedded in epoxy resin 618, Ultrathin sections, uranyl acetate and lead citrate were stained. The growth and development of BBB in different days after birth were observed under Hitachi Hu-12A transmission electron microscope. Results On the 1st, 14th, 28th and the 42nd days of birth, BBB in the brain of Kunming mice showed tight junctions between endothelial cells and endothelial cells, and the basement membrane and astrocyte processes Microstructure showed significant differences. There was no intact basal membrane in the brain tissue of the first day of life, but only the basement membrane-like substance around the capillaries with discontinuity, uneven thickness and electron density. The cells of neurons and glia were close to the endothelium Cells; With the growth and development, on the 14th and 28th day of birth, the microvascular wall of Kunming mice became thinner and the basement membrane gradually became clear and complete. At day 42 of birth, the BBB of Kunming mice developed further, the basement membrane was thick and dense, Yuan and glial cell body away from the blood vessels. Conclusion Neonatal mice BBB is not mature, is a key part of brain injury prone.