Objective      To determine the effect of tetramethylpyrazine (TMP) on the expression of caspase-8 and CytC in interleukin-1β (IL-1β) induced rabbit articular chondrocytes.        Methods      The chondrocytes derived from the joint of rabbits were isolated and primarily cultured. Toluidine blue staining was used to detect proteoglycan

and immunofluorescence assay was employed to detect collagen type Ⅱ to identify rabbit primary cartilage cells. Rabbit cartilage cells were divided i

nto control group

IL-1β group (10 ng/mL)

IL-1β plus TMP groups (10 ng/mL IL-1β plus TMP at different concentrations of 5

10

15

and 20 μg/mL respectively) for 48 h. Caspase-8 expression was detected by Western blotting and immunohistochemical assay. And the intracellular expression of CytC was measured by ELISA.       Results      Our obtained primarily cultured chondrocytes grew in adherence

in a triangle or polygon shape. Proteoglycan and collagen typeⅡ were mainly expressed in the cytoplasm

but the later was rarely located in the nucleus. Compared with the control cells

the expression of caspase-8 and CytC was significantly enhanced in the chondrocytes treated by IL-1β alone or combined with TMP at different concentrations (

P

0.01)

and the expression was obviously lower in the cells treated by IL-1β+15 μg/mL TMP than in the cells treated by IL-1β alone (

P

0.05

P

0.01).        Conclusion      TMP inhibits the expression of caspase-8 and CytC in rabbit chondrocytes induced by IL-1β

and thus

suppresses cell apoptosis.