The Effects Of RhGH On Burned Rats Wound Healing And Its Mechanism

Objective:To explore the effection and mechanism of the recombinant human growth hormone(rhGH)in burned rats,and providing the basis for clinical treatment of burns.Methods:1.A total of 50 SD rats of 300±20g were selected to establish a burn model,and randomly divided into 5 groups.Group A was set as the control group,and 1.0 ml of normal saline was injected in the edge of burn wound;Group B and C were injected subcutaneously with rhGH at concentrations of 0.2 IU and 0.4 IU/ml in normal saline 1ml;and group D and E were injected abdominal subcutaneously with rhGH at a concentration of 0.2 IU and 0.4 IU/ml in normal saline 1ml.And the blood glucose was measured.2.After the model was established,the rats' body weight changes,feeding and drinking of would be observed every day,the proliferation of granulation tissue in the bum wounds of each group was observed,and recorded the number of days of the scabs appears.The wound healing was observed at 5 days,10 days,and 15 days after burns in 4 groups of rats,and took photos and collected the burn wound skin specimens.3.The specimens were fixed with 4%formaldehyde and made into paraffin sections.The pathological structure and microvessel production of burn wound skin in rats would be observed by HE staining.At the same time,immunohistochemistry was used to detect the expression and distribution of VEGF and CD34 in endothelial cells,and calculated the MVD.Results:1.The 5 groups of burned rats healed after the passage of time.On the 5th day of group A,there were still redness and swelling in the burn wounds,but compared with the group A,the burn wounds of rats in the other 4 groups were significantly better,and the 4 groups showed less oozing,and a small amount of granulation tissue proliferation was observed;On day 10,the granulation tissue of the wounds in group B,C,D and E was obviously proliferated;On the 15th day,a small amount of granulation tissue proliferation began in group A,while wounds in the other 4 groups were dry,and a small amount of newborn hair appeared in all the groups.Although the blood glucose of group B,C,D and E is higher than group A on the 5th day,it wasn't too obvious(P>0.05).2.The number of microvessels in the 5 groups increased on the 5th day,but the group B,C,D and E were significantly more than the group A(P<0.05).On the 10th day,the granulation tissue of the wounds in the group B,C,D and E was mature,and the fibroblasts around the microvessels were clearly visible.On the 15th day,the group B,C,D and E could see obvious level of skin structure.3.Compared with the group A,it was found that the positive expression in VEGF-containing cells of the group B,C,and D was increased after 5 days of treatment(p<0.05),which was statistically significant,and the number of CD34 antigen expression in endothelial cells increasing obviously.And on the day 10th day and 15th day,the positive expression in VEGF and CD34 is still increasing than before.Conclusion:1.The application of rhGH in treating burned rats have a good effect,it will hasten the wound healing and promote the burned wound recovery.Although the levels of blood glucose would increase temporarily after using rhGH,it won't get in the way of the wound healing.2.Using rhGH can significantly increase the positive expression in VEGF and CD34,and the number and density of wound microvessel,which is a promoting effect on the repair of wounds.