[The influence of zi-hua burn cream on the survival of random skin flaps in rats].

OBJECTIVE: To observe the effect of zi-hua burn cream on the survival of skin flaps in rats, and its mechanisms. METHODS: 72 Wistar rats, were randomly divided into four groups as zi-hua group(n = 18, external application of alfalfa burn cream), control group (n = 18, external application of heparin sodium cream), model group (n = 18, external application of vaseline) , negative control (n = 18, no operation). 8 cm x 2 cm random skin flaps with pedicle on the side of head were designed on the back of Wistar rats. The drug was applied on the flap surface, 2 times a day. The survival of skin flaps was observed. The change of serum superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), turner necrosis factor-alpha(TNF-alpha)and interleukin-6(IL-6)were compared at 1,2,3,7 d after operation, and histologic examination was performed. RESULTS: The survival rate of zi-hua group (73.58 - 10. 74)% was significantly higher than that of model group (33.40 - 16.05) %, showing a statistical difference (Q = 10.63, P <0.01). There was no significant difference between the zi-hua group and control group (71.65 +/- 11. 92) %. The level of serum SOD, NO in zi-hua group and control group was higher than that in model group, while the level of serum MDA, TNF-alpha and IL-6 was lower than that in model group(P <0.01). On 7 day after operation, skin flaps tissue edema,necrosis and inflammatory cell infiltration in zi-hua group and control group was less obvious than that in model group. There was significant proliferation of granuloma and fibroblast and formation of neonatal capillary in zi-hua group and control group. The vascular density in zi-hua group was obviously higher than that in the model group and control group(P <0. 01). CONCLUSIONS: Zi-hua burn cream could significantly improve the blood supply of skin flaps, increase the survival rate of skin flaps in rats. Its mechanism may be associated with the anti-free-radical-damage action, improve local microcirculation, improve the NO content, reduce the TNF-alpha and IL-6 level, reduce inflammation factor release, improve oxidative stress state, and reduce inflammation reaction.

[Effect of low molecular heparin sodium cream on the content of serum nitric oxide in random pattern skin flap: experiment with rats].

OBJECTIVE: To explore the mechanism of improvement of blood circulation in random pattern skin flap by low molecular heparin sodium cream. METHODS: 48 Wistar rats underwent formation of random skin flap of the size of 2 cm x 8 cm on the back and then were randomly divided into 2 equal groups: experiment group with low molecular heparin sodium cream smeared on the skin flaps and control group with Vaseline smeared on the skin flaps. 24, 48, and 72 hours, and 7 days after the smearing blood samples were collected from 6 rats respectively to detect the content of serum nitric oxide a (NO). Seven days after the smearing specimens were collected from the upper, middle, and lower parts of the skin flaps to undergo pathological examination. RESULTS: (1) The serum NO content of the experiment group was (53 +/- 15) micromol/L, significantly higher than that of the control group [(27 +/- 20) micromol/L, P < 0.05] 7 days after the operation. (2) The skin flap survival rate of the experiment group was (66 +/- 18)%, significantly higher than that of the control group [(22 +/- 16)%, P < 0.01]. (3) Histomorphology showed formation of neo-vessels with integrated endangium of capillary, stability of structure of mitochondria, and milder cell swelling in the flaps treated with heparin cream. CONCLUSION: Low molecular heparin sodium cream increases the content of serum NO, thus increasing the survival of skin flaps.