Effect of apelin hormone on random flep viability in rad

Purpose: Due to the advantage of convenient procedure, randomly patterned skin flaps are often applied in extremity reconstruction and wound repair. Apelin-13 is a discovered endogenous peptide that has been shown to have potent multiple biological functions. Recently, thermosensitive gel-forming systems have attracted increasing attention as wound dressing materials due to their advantages. In this study, an in situ gel formulation was prepared using apeli-13 loaded, poloxamer 188 and p0loxamer 407 to support the survival of the random skin flap, and its effect was examined in the random flap model. Materials and Methods: Experimental animals were randomly divided into four groups. Animals in the first group were divided into control groups and the other groups were divided into subgroups according to the application of apelin-containing gel or apelin-free gel during the ischemia/reperfusion protocol in order to test the effect of applying apelin substance on gel formation in ischemia-treated flaps. 1st Group Control Group (n=6) 2nd Group Random flap ischemia-reperfusion group (n=12) 3rd Group Random flap Apelin-free gel group (n=12) 4th Group Random flap Apelin containing gel group (n= 12). Random skin flaps, which are frequently used in daily practice, will be used as flaps. A 3x9 cm caudal pedicle dorsal peninsula flap (Mc Farlane flap) was removed from the rat dorsum. Then, the flaps would be returned to their original places, and the flaps, half of which were amputated on the 7th postoperative day and the other half on the 14th postoperative day, were subjected to detailed examination for macroscopic, histological and biochemical signs of ischemia-reperfusion damage. In the study, histological examinations will be performed using immunohistochemical markers VEGF, i-NOS and e-NOS, nNOS. Intracardiac blood samples were taken for biochemical analysis and hemogram VEGF, SOD, CAT, n-NOS, i-NOS, e-NOS, TNF-α, IL-1β, MDA, IL-6, TGFβ levels were obtained from blood and serum samples. was measured. Results: In the immunohistochemical findings of the study, iNOS, eNOS and iNOS expression was determined immunohistochemically and expression levels were found to be lower in the flap group compared to the control group, suggesting that oxidative stress increases with I/R damage. In the gel and Apelin gel application group, it was observed that iNOS, eNOS and nNOS expressions increased. iNOS and nNOS levels were analyzed in serum samples. While there was no significant difference in serum levels between the groups, eNOS levels were found to be significantly higher in the apelin gel group than in the flap group (p<0.001). However, it was observed that the levels of antioxidant enzymes such as serum CAT and SOD decreased significantly in the flap group compared to the control group (p<0.001), and increased significantly in the apelin-loaded gel group (p<0.001). Conclusion: We observed the positive effects of the prepared apelin-13 gel loaded flaps on flap-induced ischemia with histopathological and immunohistochemical data, and we also demonstrated that it can have positive effects on flap survival due to its antioxidant activity by suppressing oxidative stress, with its positive effects on antioxidant parameters. Our study is a first with detailed histological, immunohistochemical and biochemical data on random flap survival of the apelin-13 loaded in situ gel prepared with poloxamer 188 and ploxamer 407.