Endogenous erythropoietin level and effects of exogenous erythropoietin in a rat model of blunt chest trauma-induced pulmonary contusion

BACKGROUND: The present objective was to investigate endogen erythropoietin (EPO) level and relationship to oxidative stress within the first 24 hours of blunt chest trauma-induced pulmo-nary contusion (PCn) in a rat model.
METHODS: Thirty-five rats were divided into 3 groups. In the baseline control group (BC, n=7), rats were uninjured and untreated. In the positive control group (PC, n=21) rats were injured but untreated. In the EPO-24 group (n=7), rats were injured and a single dose of intra-peritoneal EPO (5000 IU/kg) was administered immediately after lung injury. The PC group was divided into 3 subgroups: PC-6 (n=7), PC-12 (n=7), and PC-24 (n=7). The BC group was subjected to thoracotomy, and the right lung was harvested. The PC subgroups were eu-thanized at 6, 12, and 24 hours after injury, respectively. The EPO-24 group was euthanized at the 24th hour after injury. Lung samples were obtained, levels of malondialdehyde (MDA) and EPO were analyzed, and activities of superoxide dismutase (SOD) and catalase (CAT) were then measured in homogenized lung tissue samples. Histologic damage to lung tissue in the BC group, the EPO-24 group, and PC subgroup euthanized at the 24th hour after injury were scored by a single pathologist blinded to group assignation.
RESULTS: Mean MDA levels, as well as SOD and CAT activities, of the BC and EPO-24 groups were significantly lower than those of the PC group (p<0.005). Mean EPO concentra-tion of the PC group was significantly higher than that of the BC group (p<0.005). Lung tis-sue damage scores measured at 24 hours after injury were significantly lower in the EPO-24 group than in the PC group (p<0.005).
CONCLUSION: In the present PCn rat model, EPO concentrations, as well as SOD and CAT levels, were high in lung tissue, when measured at 24 hours after PCn. When administered early after chest trauma, EPO significantly attenuated oxidative damage and tissue damage in the early phase, as assessed by biochemical markers and histologic scoring.

Künt göðüs travmasýyla oluþturulan pulmoner kontüzyon sýçan modelinde eritropoietin düzeyleri ve eksojen eritropoietinin etkileri

AMAÇ: Sýçanlarda oluþturulan künt göðüs travmasýna baðlý akciðer kontüzyon modelinde, ilk 24 saat içinde endojen eritropoetin düzeylerinin oksidatif stresle iliþkisi ve ekzojen eritropoietinin etkilerini araþtýrmayý amaçladýk.
GEREÇ VE YÖNTEM: Otuz beþ sýçan üç gruba ayrýldý: Grup BC (bazal kontrolü, n=7), herhangi bir iþlem yapýlmadý; Grup PC (pozitif kontrol, n=21), sýçanlarda kontüzyon oluþturuldu fakat tedavi verilmedi; Grup EPO-24 (eritropoietin tedavi, n=7), sýçanlarda kontüzyon oluþturuldu ve künt göðüs travmasýndan hemen sonra intraperitonal (5000 lU/kg) tek bir doz eritropoietin verildi. Pozitif kontrol grubu her grupta yediþer sýçan olacak þekilde üç alt gruba ayrýldý (PC-6, PC-12, PC-24). PC-6, PC-12, PC-24 grubundaki sýçanlar, künt travmadan 6, 12 ve 24 saat sonra, EPO-24 ve BC grubundaki sýçanlar ise travmadan 24 saat sonra öldürüldü. Akciðer dokusunda malondialdehit (MDA) ve EPO düzeyleri, süperoksit dismutaz (SOD) ve katalaz (CAT) aktiviteleri ölçüldü. BC, PC-24 ve EPO-24 gruplarýnda histopatolojik incelemeyle total doku hasarý saptandý.
BULGULAR: Ortalama MDA düzeyleri, SOD ve CAT aktiviteleri BC ve EPO-24 gruplarýnda PC grubuna göre düþüktü (p<0.005). PC-6, PC-12 ve PC-24 grubunun ortalama EPO konsantrasyonu BC grubuna göre daha yüksek bulundu (p<0.005). Akciðer doku hasarý skorlarý EPO-24 grubunda PC-24 grubuna göre daha düþüktü (p<0.005).
TARTIÞMA: Eritropoietin konsantrasyonlarý, SOD ve CAT düzeyleri pulmoner kontüzyon sonrasý ilk 24 saatte akciðer dokusunda yüksek olduðu saptandý. Göðüs travmasý sonrasý akut dönemde uygulanan tek doz intraperitoneal eritropoetin (5000 IU/kg), travmanýn erken döneminde oksidatif hasarý ve doku zedelenmesini azaltmaktadýr.