脑源性神经营养因子及其受体酪氨酸激酶B在慢性高眼压猕猴初级视皮层的表达

Expression of Brain-derived Neurotrophic Factor and Its Receptor Tyrosine Kinase B in Primary Visual Cortex of Chronic Ocular Hypertension Monkeys

目的探讨不同时期慢性高眼压猕猴初级视皮层脑源性神经营养因子(brain-derived neurotro-phie factor,BDNF)及其受体酪氨酸激酶 B(tyrosine kinase B,TrkB)表达的改变及其意义。方法取4只健康猕猴和11只由激光小梁网烧灼法造成的不同时期慢性高眼压猕猴的初级视皮层,做冠状面和切线位冰冻切片,免疫荧光组织化学法检测 BDNF 和 TrkB,图像分析法计算每10000μm^2组织中 BDNF 阳性区域面积并进行方差分析。结果健康猕猴初级视皮层 BDNF 表达丰富,冠状面及切线位 BDNF 阳性区域面积分别为(432.54±115.90)μm^2和(693.38±354.59)μm^2,青光眼组 BDNF 表达普遍降低,分别为(90.42±75.10)μm^2(P=0.000)和(354.36±194.58)μm^2(P=0.031),与健康对照组间差异有统计学意义,但与病程无关。青光眼组TrkB 表达也呈不同程度减弱。结论慢性高眼压猕猴初级视皮层的 BDNF 及 TrkB 表达降低,可能通过削弱下行营养支持,加重了视觉通路中下级神经元的病变,从而参与了青光眼病理机制中的恶性循环。(中国眼耳鼻喉科杂志,2007,7:279-281)

Purpose To investigate the expression of brain-derived neurotrophic factor （BDNF） and its receptor tyrosine kinase B（TrkB） in primary visual cortex in monkeys with chronic ocular hypertension at different stages. Methods The subjects included 4 normal monkeys and 11 monkeys with unilateral or bilateral chronic ocular hypertension induced by laser scarification of the trabecular meshwork. Coronal and tractional sections of visual cortex were cut on cryomicrotome. BDNF and TrkB expression was studied by fluorescent immunohistochemistry. Positive area of BDNF expression in each 10000 μm^2 tissue was counted. Statistical comparisons were made using one-way ANOVA. Results The expression of BDNF within primary visual cortex in normal monkeys was （432.54 ± 115.90） μm^2 in coronal sections and （693.38 ± 354.59 ） μm^2 in tractional sections, which decreased to （90.42 ± 75.10 ）μm^2 and （354.36 ± 194.58 ） μm^2 in glaucomatous monkeys （P 〈 0.05 ）. The difference wasn＇t correlated with the course of disease. The expression of TrkB also decreased of glaucomatous monkeys. Conclusions The decreased expression of BDNF and TrkB might participate in the vicious circle in glaucomatous pathogenesis via lessening retrograde nutritional sustainments. （ Chin J Ophthalmol and Otorhi nolaryngol, 2007,7 ： 279 -281 ）