Acute influence of FK506 on T-lymphocyte populations of peripheral blood and spleen in rats.
BACKGROUND
Tacrolimus (FK506) is an immunosuppressive agent used in clinical transplantation. We studied the acute impact of FK506 on T-lymphocyte populations of peripheral blood and spleen in rats.


METHODS
The animals injected with FK506 (2 mg/kg) subcutaneously were sacrificed at 12, 24, or 48 hours after administration. CD3(+), CD4(+) and CD8(+) T-cell populations in peripheral blood and spleen were analyzed by FACS.


RESULTS
After treatment with FK506, the proportion of CD4(+) cells significantly increased in the spleen at 12 hours, decreasing to control levels at 24 and 48 hours. There was a slight increase in the CD4(+) subpopulation in the peripheral blood at 12 and 24 hours and a significant increase at 48 hours. The CD8(+) T-cell subpopulations in peripheral blood and spleen were stable during FK506 administration.


CONCLUSIONS
These results indicated that FK506 increased CD4(+) spleen lymphocyte activation in a short time, inducing a subsequent increase in CD4(+) cells subsets in peripheral blood.
Wang
M
M
School of Medicine, Nanjing University, China.
Li
N
N
Zhang
Q
Q
Ma
J
J
Li
Q
Q
D000818:Animals; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D005434:Flow Cytometry; D018655:Lymphocyte Count; D008297:Male; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000187:drug effects / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D016559:Tacrolimus / Q000494:pharmacology*
D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D016559:Tacrolimus