穿通支原体诱导膀胱肿瘤实验研究

Experimental study on the mouse model of bladder tumor induced by Mycoplasma penetrans

目的建立穿通支原体(Mpe)诱发的膀胱肿瘤动物模型,进一步证实穿通支原体感染在哺乳动物体内诱导癌变的作用。方法40只ICR小鼠分免疫抑制和非免疫抑制组(每组20只)。免疫抑制组隔日腹腔注射环磷酰胺制成免疫抑制模型。穿通支原体菌液灌胃(12只)和尿道上行感染(16只),NS对照(12只),诱导小鼠膀胱肿瘤的发生,实验组在第4,8,18w分批宰杀,取小鼠膀胱组织进行微生物学和病理组织学检查。结果两种方式感染均使穿通支原体成功定植。尿道上行方式感染的小鼠移行上皮细胞癌变检出率高于灌胃方式感染;感染至18w后,上行感染免疫抑制组和正常组小鼠膀胱移行上皮细胞形态均发生了癌性恶变,且免疫抑制组细胞形态恶变程度为高。感染18w后的癌变检出率明显高于感染4w或8w后的小鼠。结论穿通支原体感染可诱导小鼠膀胱移行上皮细胞癌的发生,并且肿瘤的恶性程度与宿主的免疫状态有关。

The aim of this study is to develop a mouse model of bladder tumor induced by Mycoplasma penetrans （Mpe） and to further confirm the role of infection with mycoplasma to induce the development of bladder tumor in mammalian animals. Forty ICR mice were randomly divided into two groups, i.e. the immunosuppressive group and the non-immunosuppressive group, （20 mice in each group）, in which the former was render to he immunosuppressive by intra-peritoneal injections of cyclophosphamide every other day. In 14 mice of the immunosuppressive group, 6 mice were infected with Mpe through gastric lavage; 8 mice were infected by ascending infection through urethra, and in 6 mice of the non-immunosuppressive, mice （3 in each group） were treated with physiological saline either through gastric lavage or through urethra. The treated mice were kill- ed 4, 8 and 18 weeks later and the bladder tissues were taken for microbiological and pathological examination by light and elec- tron microscopy to observe the morphological changes of the bladder migratory cells. The experimental results showed that Mpe could colonized successively on bladder through both routes of inoculation of mycoplasma by gastric lavage and through urethra. The detection rate of the cancerous changes in the migratory cells of bladder induced through urethral route was higher than those induced through gastric lavage. The cancerous changes were more obvious in the immunosuppressive groups of mice 18 weeks after infection with Mpe and they were more prominent than those induced after 4 or 8 weeks after infection. From these observation, it is clear that infection with Mycoplasma penetrans can induce the development of cancerous changes in mouse bladder migratory epithelium, and degree of malignancy is related to the immune status of mice.