电压依赖性钙通道α1F亚单位缺陷对小鼠视网膜组织结构和功能的影响

Effect of voltage-dependent calcium channel α1 F subunit deficiency on the structure and function of the murine retina

目的探讨电压依赖性钙通道（VDCC）α1F亚单位在小鼠视网膜组织中的分布和意义。方法实验研究。将70只小鼠分为两组，实验组为VDCC0α1F-/-小鼠（突变纯合子），对照组为α1F＋/＋小鼠（野生型），每组35只。免疫荧光法检测两组小鼠视网膜组织中α1F亚单位的表达情况；两组小鼠于生后3、6、9、14d和3个月分别行视网膜石蜡切片观察显微结构；并记录两组小鼠闪光视网膜电图（ERG）。两组小鼠ERG振幅的比较采用独立样本t检验。结果（1）实验组小鼠视网膜组织中VDCC仅．F亚单位呈阴性表达；对照组小鼠视网膜组织中VDCCα1F亚单位呈阳性表达，主要分布于视网膜外丛状层（OPL），内丛状层和神经节细胞层可见少量表达。（2）α1F-/-小鼠出生后视网膜组织中的OPL逐渐变窄，至3个月龄时几乎消失；而d．F＋/＋小鼠视网膜OPL厚度始终变化不大。（3）α1F-/-小鼠暗适应标准强度闪光ERGb波振幅[（163．8±26．7）肛V]较仅。F＋/＋小鼠[（408．4±54．5）α1V]明显降低（t=-9．017，P=0．000），而d1FI／-小鼠a波振幅[（208．2±27．3）μV]与d1F＋/＋小鼠[（196．0±24．2）μV]的差异无统计学意义（t=0．748，P=0．476）。结论VDCCα1F亚单位缺陷主要影响小鼠视网膜OPL的结构和功能。

Objective To investigate the distribution and biological roles of voltage-dependent calcium channel （VDCC） cqF subnnit in murine retina. Methods Experimental study, α1F-/- （homozygous mutant） mice （ n = 35） and cqF＋/＋ wild type） mice （ n = 35 ） were used in this study. Immunohistochemistry was performed to determine the expression of VDCC cq F subunit in the mouse retina. Retinae in α1F -/ mice and age-matched control mice at 3,6,9,14-day and 3-month after birth were paraffin embedded, sectioned and HE stained, and full-field eleetroretinogram （ERG） were also recorded at these time points. Statistics were based on independent samples t-test. Results （ 1 ）α1F subunit was absent in OLlF-/- mice retina. But in ctlF＋/＋ice retina, α1F subunit was expressed most strongly in the outer plexiform layer （OPL）, less in the inner plexifoim layer （IPL） and ganglion cell layer （GCL）. （2） OPL thickness in the subunit deficient mice gradually reduced after birth and lost at adult age. （3） In dark- adapted ERGs, standard response showed that the b-wave amplitude of α1F -/- mice [ （ 163.8 ± 26. 7 ） μV ] significantly decreased compared with that of α1F＋/＋ice E （408.4± 54. 5 ） μV] （ t = - 9. 017, P = O. 000 ） , whereas the a-wave amplitude of α1F- / - group [ （208.2 ±27.3 ） μV ] was similar to that of control group [ （ 196. 0 ± 24. 2 ） μV ] （ t = 0. 748,P = 0. 476）. Conclusion This study demonstrates that the lack of VDCC α1F subunit affect the structure and function in the OPL of the murine retina.