To establish a rabbit model of diabetes mellitus in combination with syphilis for further monitoring the dynamic changes in rabbits' kidneys and investigating the possible pathogenic mechanism.

Twenty-four male rabbits were divided into four groups including diabetes group (group DM, n=8), syphilis group (group T, n=5), diabetes mellitus in combination with syphilis group (group H, n=8) and control group (group C, n=3). The rabbit models for groups DM, T and H were respectively established by injecting rabbits with alloxan, Treponema pallidum strains and alloxan in combination with Treponema pallidum strains. Kidney damages in each rabbit were dynamically monitored. Immunohistochemical staining was used to measure the expression of an inflammation related protein, thioredoxin-interacting protein (TXNIP), in kidney tissues of each rabbit.

The rabbit models for three experimental groups were successfully established. Compared with the rabbits form groups T and DM, the rabbits from group H showed higher levels of blood urea nitrogen (BUN) and creatinine (Cr) since the eighth week after modeling. Compared with the rabbits form group C, those from the three experimental groups showed obvious kidney damages and the most severe damages in kidney tissues were observed in rabbits from group H. Results of the immunohistochemical staining showed that the expression of TXNIP in kidney tissues were enhanced in rabbits from the three experimental groups, especially in those from the group H.

Diabetes mellitus in combination with syphilis could induce more severe kidney damages in rabbits than those induced by diabetes or syphilis alone. The possible mechanism might relate to the hyper-expression of TXNIP in kidney tissues.

Diabetes mellitus; Syphilis; Rabbit model; Kidney damage; Thioredoxin-interacting protein