ABSTRACT
Gum tragacanth is a natural complex mixture of polysaccharides and alkaline minerals extracted from species of Astragalus plant, which is found widely in arid regions of the Middle East. In a pilot experimental study we examined the effects of its topical application on wound healing in ten albino adult male rats. Two similar parasagittal elliptical full-thickness wounds [control vs. test samples] were created on the dorsum of each animal. Test group samples were fully covered by a thin layer of gum tragacanth daily. The extent of wound healing was evaluated by planimetric analysis on multiple occasions during the 10-day study period. On the 7[th] day of the study, the percent of wound closure was significantly higher in gum tragacanth-treated specimens compared to the control samples [87% +/- 2% vs. 70% +/- 4%, P<0.001]. The majority of wounds in the test group were completely closed by the 10[th] day of the study. The difference in wound healing index measured by histological examination on day 10 of the study was also statistically meaningful between the two groups [0.624 +/- 0.097 vs. 0.255 +/- 0.063, P<0.05]. The results of this study clearly showed the useful effects of topical application of gum tragacanth in acceleration of skin wound contraction and healing. More studies are encouraged to identify the implicating agents and precisely understand the mechanism by which they exert their wound healing effects
Subject(s)
Animals, Laboratory , Skin , Tragacanth , Astragalus Plant , Rats, WistarABSTRACT
Impaired wound healing in ischemic tissues such as skin flaps resulting from inefficient perfusion is one major cause of complications in plastic surgery. In present experimental study, we investigated the effects of fibroblast growth factor-2 [FGF-2 or bFGF] and erythropoietin [EPO] in prevention of skin flap necrosis in rats. 30 adult albino rats were randomized into 3 groups: in control group, normal saline solution; in EPO group, erythropoietin [100U/ kg/day]: and in FGF-2 group, fibroblast growth factor-2 [2,5 microg/day] were injected subcutaneously in 3 daily consecutive doses in the designated flap areas before creating 4:1 random pattern skin flaps on the dorsum of animals. Areas of ischemic [S] and necrotic [S[N]] zones were measured and compared in all groups one week after the flap creations. The necrotic zone [S[N]], as well as the ratio of the necrotic zone to the total discolored zone [S[N]/[S[I]+S[N]]] were substantially larger in the control group [41% +/- 7%, 90% +/- 6%] compared to the EPO [20% +/- 2%,42% +/- 4%] and the FGF-2 [8% +/- 2%,19% +/- 3%] groups [p < 0.001]. The differences in these values were also meaningful between the EPO and FGF-2 groups [p < 0.001].Vascular density in ischemic area of the control group was less than those in the EPO and the FGF-2 groups; however, the differences were not statistically significant between any of the groups [p > 0.05]. Local administration of erythropoietin or fibroblast growth factor-2 in skin flaps could remarkably increase tissue viability and accelerate the wound healing process. However, the therapeutic effect of fibroblast growth factor-2 in preventing the necrotic event in, ischemic zones of skin flaps is much more considerable than that of erythropoietin
ABSTRACT
We report experimental myocardial infarction by occluding coronary arteries in ovine models. Twelve ewes were included in the study. After the chest was opened by left lateral thoracotomy incision, the second diagonal branch of the left anterior descending coronary artery was ligated at a point approximately 40% distant from its base. Prophylactic antiarrhythmics were administered. Animals were mechanically ventilated during surgery and stayed in the ICU for 24h afterwards. Experiments were then evaluated by echocardiographic, electrocardiographic, hemodynamic, serologic and morphologic investigations. Echocardiographic measurements were repeated after two months and animals were then sacrificed for postmortem cardiac examinations. All animals survived the surgical procedure. Cyanotic discoloration and hypokinesia in the cardiac tissue in an area of 3x4 cm plus ST-segment elevations was detected immediately after vessel ligation. More over, there were pathologic Q-waves 2 months later. Echocardiographic evaluations revealed an average of 22% relative decrease in cardiac ejection fraction. Wall motion analysis demonstrated anteroapical hypokinesia and akinesia in all animals one day and two months after operation. Thin walled infarcted areas with tissue fibrosis were evident in pathologic investigations two months after surgery. In conclusion, we developed a practical and safe method of producing myocardial infarction in large animal models