Protective effect of Minocycline on photoreceptor cell in retinal pigmentary degeneration mice

Objective To observe the effect of Minocycline on RP process of retinal pigmentarydegeneration rd mice[C3H/HeN(Pde6brd-/rd-)]. Methods 40 rd mice were divided into ten groupsrandomly:5 experimental groups and 5 control groups,4 rd mice in each group.The experimental groupreceived intraperitoneal injection of minocycline 22.5mg/kg while the control group received saline 10ml/k2 every day from the posmatal day 1(P1).Mice were sacrificed at P1,P7,P14,P21 and P28respectively.Eyeballs were enucleated to carry out histology observation and apoptosis cell detection.Meanwhile,to statistically analyze the number of retinal photoreceptor cells,the thickness of outer nuclearlayer(ONL)and the number of apoptosis cells. Results (1)Photoreceptor cell began to apoptosis onP7,peaked on P14,and totally disappeared on P28.(2)No statistically significant differences were foundof the number of photoreceptor cells and the thickness of ONL on P7 between the experimental group andthe control group.(3)The number of photoreceptor cells and the thickness of ONL in the experimentalwere more than that in the control group at P14,P21,P28 respectively,the differences are statisticallysignificant(P＜0.05).(4)The apoptotic cells on ONL were less in the experimental group than that in thecontrol group on P7 and P14 respectively,the difference are statistically significant(P＜0.05).Conclusions Minocycline appears to protect photoreceptor cell from apoptosis in the early stage of theretinal degeneration mice,but it may not completely prevent RP from occurrence. Key words: Minocycline/therapeutic use; Retinitis pigmentosa; Mice,inbred C3H