[Effect of different concentration of tamoxifen ointment on the expression of TGF-beta2 of hypertrophic scar at rabbit ears].

Objective: To observe the effect of different concentration of Tamoxifen ointment on the fibroblasts and transforming growth factor (TGF-beta2) of hypertrophic scar at rabbit ears, so as to explore the possibility of treatment of hypertrophic scar with Tamoxifen.

Methods: The hypertrophic scar model was established in 96 New Zealand rabbits' ears. The wounds were divided into four groups (A, B, C and D), with 144 wounds in each group. Different concentration of tamoxifen ointment (0.5%, 1%, 2%) was topically administered in groups A, B and C respectively, and blank ointment in group D. On postoperative day 30, 60 and 90, the scar samples were harvested. The scar thickness, scar histological change and the content of TGF-beta2 were detected.

Results: (1) On the 30th day after operation, the difference of scar tissue thickness among groups A, D and B, C reached statistical significance (group A, D < group B < group C). However, there was a contrary tendency in fibroblasts density and TGF-beta2 content of the scar tissue simultaneously. (2) On 60th, 90th day after injury, there was statistical difference in scar thickness, fibroblasts density and the content of TGF-beta2 in scar of four groups (P < 0.05). The content of TGF-beta2 in group A, B, C, D was (43.97 +/- 3.63) microg/L, (41.92 +/- 3.91) microg/L, (36.69 +/- 4.15) microg/L, (54.90 +/- 4.71) microg/L, respectively, on 60th day; and (45.69 +/- 2.63) microg/L, (40.43 +/- 3.87) microg/L, (38.76 +/- 3.24) microg/L, (52.59 +/- 4.92) microg/L, respectively, on 90th day. The fibroblasts density of scar in groups A, B, C, D was (4392.07 +/- 327.84) point/mm2, (4208.57 +/- 329.76) point/mm2 (4 033.44 +/- 427.91) point/mm2, (4863.03 +/- 387.98) point/mm2, respectively, on 60th day; and (4418.41 +/- 432.52) point/mm2, (4077.65 +/- 386.70) point/mm2, (3844.53 +/- 354.29) point/mm2, (4838.64 +/- 390.52) point/mm2, respectively, on 90th day. The content of TGF-beta2 and fibroblasts density of scar were lined up as group D > group A > group B > group C (P < 0.05).

Conclusions: Topical Tamoxifen can reduce the content of TGF-beta2 and fibroblast, decrease fibroblasts density and the formation of hypertrophic scar at rabbit ears. It offers a new way for the treatment of the hypertrophic scar.