Objective    To investigate the effects of 1

25-dihydroxyvitamin D

3

in the prevention of corneal allograft rejection.     Methods    Forty-five SD rats (only right eyes) were used as recipients

and 15 Wistar rats (double eyes) were used as donors. SD rats were randomly divided into 3 groups: the autograft control group

the allograft control group (receiving peanut oil as placebo)

and  the allograft group were treated with 1

25-dihydroxyvitamin D

3

1.0 μg ·kg

-1

·d

-1

3 times/d for 13 d

i.p.). Drugs were injected intraperitoneally for 14 d after transplantation. Routine antibiotic eye drops were used. Grafts were observed by operating microscopy everyday after transplantation. Five SD rats in each group were killed respectively at the 14

21

and 30 d postoperatively. Neovascularization and inflammation were evaluated with HE staining. ELISA was used to detect the contents of IL-1β

IL-2

IL-8

and IL-10 in the peripheral blood.     Results    The mean survival time (MST) of the graft was (21.7±6.8) d  in the autograft control group

(11.2±2.5) d in the allograft control group

and (19.3±5.2) d in the allograft group. There was statistically significance between the latter 2 groups (P0.01). The allograft group had less neovascularization and inflammation than the allograft control group; the blood levels of IL-1β

IL-2

and IL-8 were markedly lower in the former than in the latter group

but IL-10 were significantly higher (P0.01).     Conclusion    1

25-dihydroxyvitamin D

3

can prolong the survival time of corneal grafts by inhibiting the immune rejection of corneal transplantation.