Experimental Research Of Effection Of RhGH On Narrow Pedicle Flaps Survival In Rats

Objective: Subcutaneous injection of rhGH on the back of narrow pedicle flap of theadult rat，and with two different methods of local and systemic injection. Observing rhGHand its two different injection ways impact on the influence degree of survival area ofnarrow pedicle flap,and exploring the mechanism of the rhGH affect on flap survival.Methods: We chose80healthy SD rats and each rat was designed and made a narrowpedicle flaps on the one side of back which distance of the central line was1cm. Thepedicle size was1.0×1.0cm while the flap size was2.5cm in diameter circular.After thecompletion of the production of narrow pedicle flap,80rats were randomly divided intoflap local medication group (group Ⅰ) which were subdivided into experimental group(group Ⅰa) and control group (group Ⅰb) and systemic medication group (group Ⅱ)which were subdivided into experimental group (group Ⅱa) and control group (groupⅡb).Every group has20rats. After surgery, the flap of rats were subcutaneously injectedwith rhGH(0.1IU/Kg·d) for7days in group Ⅰa, while used the same method and dose ofN.S. in group Ⅰb. And the flap of rats were systemic injected with rhGH(0.1IU/Kg·d) for7days in group Ⅱa, while used the some method and dose of N.S. in group Ⅱb. At thesame time the four groups of rats were observed. And the flap survival rate of each flapwas measured on the seventh day after surgery. Collecting the specimens at the distal flapof the four groups at days0,1,3,5,and7after operation. We observed the flaps tissues undermicroscope with HE staining, And used immunohistochemical staining and enzyme-linkedimmunosorbent technology to detect the bFGF and CD34expression of the flaps. Thencalculated the microvascular density of flaps.Results:(1) According to the7days’ observation after the surgery, the percentage offlap survival area for group Ⅰa, Ⅰb, Ⅱa and Ⅱb was （100±0.00）%,（72±3.10）%,（84±2.43）%（,73±2.50）%. GroupⅠa andⅡa were significantly greater than groupⅠband Ⅱb, groupⅠa is significantly higher than group Ⅱa, P<0.05. GroupⅠb and Ⅱb wereno significant difference.(2) The expression of bFGF, CD34and MVD was increasing with time past in the same set. The expression of bFGF and CD34of group Ⅰa and Ⅱa upto highest on the third day after operation(Respectively: group Ⅰa was1531.8±9.8,45.74±0.55. group Ⅱa was1041.2±9.5,35.04±0.44). The expression of bFGFand CD34of groupⅠb and Ⅱb up to highest on the fifth day after operation (Respectively:group Ⅰb was840.9±8.8,21.13±0.42, groupⅡb was861.4±11.0,20.78±0.25).The fourgroups’ MVD up to highest on the seventh day after operation(Respectively: group Ⅰawas67.91±3.86, groupⅠb was35.51±4.87, group was Ⅱa46.71±3.76, groupⅡb34.78±5.61);(3) Compare the expression of bFGF,CD34and MVD in narrow pedicle flapsof four groups at the same point time. GroupⅠa was significantly greater than group Ⅱa,GroupⅠa andⅡa were significantly greater than groupⅠb and Ⅱb, groupⅠa wassignificantly higher than group Ⅱa, P<0.05. GroupⅠb and Ⅱb were no significantdifference. We observed the flaps tissues under microscope with HE staining, tissuevascular of groupⅠa andⅡa more than that of group Ⅰb and Ⅱb. GroupⅠa wassignificantly higher than group Ⅱa, GroupⅠb and Ⅱb were no significant difference.Conclusion:(1) Injection of rhGH on the narrow pedicle flap can promote theexpression of bFGF and CD34and further contribute to the neovascularization.(2)Injection of rhGH on the narrow pedicle flap can enhance the rate of surival.(3) Theaffection of advancing the survival of the skin flap by local subcutaneous injection ofrhGH on the narrow pedicle flap was better than that by systemic injection of rhGH.