Objective    To study the effects of a low dose of CsA combined with CVF in preventing rat cardiac allograft acute rejection.      Methods    Wistar to SD rat cardiac allograft model was employed in all groups by modified Ono’s method

and the recipi

ent rats were divided into 5 groups with 9 rats in each group: blank control (A)

half-dose CsA (B)

full-dose CsA (C)

CVF (D)

half-dose CsA combined with CVF (E). One rat in the five groups was killed daily on day 1

3

5

7

and the other five rats were used to observe the survival time of the allograft. The pathologic grade of acute rejection were compared by HE

the CD3

+

CD4

+

CD8

+

T cells infiltration by immunohistochemistry and the mRNA expressions of IL-2

IL-10 by PT-PCR were performed.     Results    The average survival days of the allograft in groups A-E were (7.88±0.99)

(14.94±1.43)

(20.76±0.94)

(14.96±2.29) and (31.10±3.36)

which was significantly shorter in group A than groups B-E (P0.01)

longer in group E than groups B-D (P0.01). The pathological grade of acute rejection was lower and CD3

+

CD4

+

CD8

+

T cells infiltration was milder in groups B-E than group A

expecially in groups C and E. The mRNA expressions of IL-2 and IL-10 was not found significant difference between group A and group D

as well as among groups B

C

E.      Conclusion    CVF and CsA has cooperativity in preventing rat cardiac allograft acute rejection. When minidose CsA combined with CVF was applied

the rejection effect would be redued significantly

even compared with the full-dose CsA treatment. CVF could inhibit the T cells infiltration in its sole application or combined with CsA

but it could not regulate the secretion of inflammatory cytokines such as IL-2 or IL-10. The mechanism of anti-rejection effect of CVF still be hazy and need progressive study.