Ischemiahas been considered as one of the most severecausative parameters leading to chronic wounds(1). Ischemia and reperfusion(I/R)injury is a pathological situation symbolized by an early limitation of blood deliverto a tissue come after by the succeeding return of perfusion and associated withreoxygenation, and consequently develops a serious disequilrium of metabolic contributeand require, creating organ hypoxia(2).
Flaptransplantation has been regarded as an essential technique in plastic surgeryto cover large defects(3), and Skinflaps may be pedicled, or free(4). I/R injury is frequently the last and permanent,that creating flap failure in plastic and reconstructive surgery (5).Mastcells (MCs) synthesize histamine and inflammatory proteins that are involved inallergic disease (6).MCs has a function in I/R injury in several tissues (7).
Recently several studies have been demonstrated inconsistent results about the effect of MCs and their degranulation activity during I/R in some tissues(7,8,9,10).Yang et al reported that MC degranulation promotes I/R injury in liver of rats(7). Georgopouloset al found that administeringhydroxyzine in rat epigastric axial skin flaps before reperfusion may decreasesnecrosis, and deceases neutrophils and MCs counts(8).
Nishioka et alinvestigated the effect of low level laser therapy(LLLT), and light emitteddiode(LED) on the viability of RSFs in rats. Nishioka et al found that both LEDand LLLT were effective in increasing viability of random skin flaps(RSF), and also the number of MCs and blood vessels in thetransition line of RSF compared to unirradiated group (9). Coneely et al examined the effect of MCs degranulation in improving anastomotic repairin an experimental model of weakly perfused large intestine in rats. Coneely etal observed MC stabilization(no degranulation releasing situation of MCs) decreased anastomotic repair in normally perfused largeintestine. Hypoperfused large intestine resulted in reduced anastomotic toughness.conversely the adding of a MC degranulating factor improved repair inhypoperfused large intestine compared to control. Coneely et al concluded that MCdegranulation is vital for early anastomotic repair in hypoperfused largeintestine(10).
Veryrecently in several investigations have been demonstrated that stem cell(SC) therapy improve viabilityof ischemic flaps in animal models(10,11,12). SCs have been shown as one of the potential therapeutic agents, following many experiments in animals (10,11,12). The positiveproperties of SCs have been attributed to considerable improvement of wound repairand in the rolling velocity of SCs(11), increased in microvascular density and red blood cellvelocity, a marked decrease of rolling and sticking of whiteblood cells, and fifty percent decrease in production of Interleukin(IL)-1 and tumor necrosis factor-? (TNF-?) under hypoxic circumstances(12),and increased paracrine expression of vascular endothelial growth factor(VEGF)(13).However, there was no study regarding evaluation the effect of SC therapy on transitionline of the RSF (where necrosis starts), which is an important site to revealthe effects of SC therapy on ischemic tissueviability (9).Appropriategrowth factors are necessary for growth and proliferation of cells (14), andmany growth factors have been identified, sequenced, and produced recombinantly(14). In this regard chicken embryo extract (CEE) hasmany growth factors that stimulate cell growth(15).
This is supported by the factthat after fertilization, a chicken develops completely in three weeks in theegg without any externally administrated growth factors (15).Incurrent study we examined the effect of bone marrow mesenchymal stem cells(BMMSCs), and CEE alone, and in combination on the flap viability, blood vessels number, and of number of MCsdegranulation in an experimental RSF in rats . Stem cell treatment of RSF wouldincrease flap survival in patients.
