Experimental study of the effect of recombination human growth hormone on the PingPang Racket flap survival / 中华显微外科杂志

ABSTRACT

Objective To investigate the effect of recombinant human growth hormone on the PingPang Racket flap survival.Methods Every two PingPang Racket flaps were designed on the both sides of 40 adult SD rats's back.The pedicle size was 1.0 cm × 1.0 cm,while the flap size was 3.0 cm in diameter circular.Longitudinal axis of flap was perpendicular to the center line of the rats back,to which the distance from proximal pedicle was about 1 cm.The flaps on the left side served as Ⅰ group,and the other side served as Ⅱ group,which were subdivided into Ⅰa and Ⅰb,Ⅱa and Ⅱb,respectively.And there were 20 rats in each subgroup.On the flap surfaces in group Ⅰ,it was 6 uniform injection poinsts,subcutaneously injecting with rhGF (the dose was 0.1IU · Kg-1 · d-1) for 7 days from the beginning of operation,that were designed.It goes the same way to the group Ⅱ,while normal saline was instead of rhGF.In subgroup Ⅰa and Ⅱa,the flaps were generally observed every day.The percentage of the flap survival area was determinated 7 days after operation.In subgroup Ⅰb and Ⅱb,specimens were collected at the distal end of flap at intraoperative(before injecting rhGF)and 1 st,3rd,5th,7th day after operation.Immunohistochemistry and enzyme-linked immunosorbent were applied to examine the expression of TGF-β1 and CD34,and the microvessel density of the flaps was calculated.Results According to the 7 days' observation after the surgery,the flap survival area percentage of subgroup Ⅰa was (97.00 + 2.12) ％,which was significantly higher (P ＜ 0.05) than that of subgroup Ⅱ a,whose was (81.00 +3.43)％.On 1st,3rd,5th and 7th day postoperatively,the expression of TGF-β1,CD34 in both subgroup Ⅰb and Ⅱb were elevated and reached peak on the 5th day.Content of GF-β1 and CD34 in Ⅰb were 1571.40 ± 13.32 pg/ml and 60.40 ±0.32 pg/ml,respectively,and in Ⅱb were 691.43 ± 11.06 pg/ml and 20.43 ± 0.06 pg/ml.At the same point of time,the expression of TGF-β1,CD34 were significant higher in Ⅰb subgroup than that in Ⅱb (P ＜ 0.05).In subgroup Ⅰb and Ⅱb,the number of microvessels increased on postoperative 1 st,3rd,5th and 7th day,especially on 3rd,5th and tended to be stable at 7th day.At the same point of time,the number of microvessels in Ⅰb was always higher than that in Ⅱb (P ＜ 0.05).Conclusion Subcutaneous injection of rhGH on flaps can enhance the expression of TGF-β1,CD34,promote microvascular generation of the flap tissue directly or indirectly,and also improve the survival of PingPang Racket flaps.