The Erythropoietin Effect on Uterus Congestion after Uterine Ischemia Reperfusion

Objective: This experiment investigated the erythropoietin (Epo) effect after uterine ischemiareperfusion (IR) in rats. The effect of Epo was evaluated studying the mean uterine congestion (UC) lesions. Materials and methods: The mean weight of 40 rats used in the study was 247.7 g. The UC lesions were estimated for the groups A and C on 60 min and for the groups B and D on 120 min after reperfusion. Only the groups C and D were administered by Epo. Results: Epo administration non-significantly declined the UC lesions scores by (without lesions) 0.15 (-0.5595137-0.2595137) (p=0.4545). Reperfusion time non-significantly raised the UC lesions scores by (without lesions) 0.15 (-0.5676974-0.3676974) (P=0.5058). However, the combined Epo administration with reperfusion time non-significantly declined the UC lesions scores by (without lesions) 0.0090909 (-0.2577992-0.2396174) (p=0.9414). Conclusions: The Epo administration presented a nonsignificantly declining short-term effect on UC lesions scores. Perhaps, a higher Epo dosage and/or an experimental time lasting longer than 2 hours may reveal more significant efficacies.


Introduction
Erythropoietin (Epo) belongs to the most occupied growth factor in biomedical studies. It implicates over 29,207 such studies at present; the 3.45% at least of which concern tissue ischemia-reperfusion (IR) models. A popular aim of Epo usage is the reverse potency of IR transient injuries of organs, including their tissues and certainly patients' health. However, satisfactory responses have not yet been received concerning basic affairs, such as, the dosage height, the administration timing, and the action velocity. The knowledge must be promoted besides the original action of Epo in red blood cells production. These specific matters require more detailed management. A numeric estimation of Epo trends was revealed by a meta-analysis of 33 published studies concerning serum variables, yielded by the present experiment ( Table 1). Table 1 The erythropoietin (Epo) influence (±SD) on the levels of some seric [1] variables concerning reperfusion (rep) time. This experiment tried to estimate the Epo action on a rat setting of IR using the mean uterine congestion (UC) lesions scores. 2 granted all consumables, facilities and equipment at Pikermi, Attiki. Pure humanistic care was provided for Albino female Wistar rats. Pre-experimental normal housing included continuous ad libitum feeding in laboratory. Euthanasia excluded the post-experimental survival and preservation of the animals. The 40 rats were randomly assigned to four equal groups. The quoting protocols of IR were used: 45 min ischemia and then 60 min reperfusion for group A; 45 min ischemia and then 120 min reperfusion for group B; 45 min ischemia and then 60 min concurrent Epo (Epoetin, rhEpo α , Janssen-Cilag, Beerse, Belgium) intravenous (IV) administration with reperfusion for group C; 45 min ischemia and then 120 min concurrent Epo IV administration with reperfusion for group D. The Epo dosage was assessed at 10 mg/Kg [1], mass per animal. Prenarcosis, general anesthesia, non-stop intraexperimental oxygen supply, electrocardiogram and acidometry are also confirmed in related references. Laparotomic clamping with forceps of inferior abdominal aorta over the renal arteries level, induced ischemia for 45 min. The forceps removal was restoring the inferior aorta reperfusion patency. Blood flow exclusions were iterated for every animal. Epo was administered starting reperfusion via inferior vena cava catheter. The UC lesions scores were estimated at 60th min of reperfusion for A and C groups groups and at 120th min of reperfusion for B and D groups. 40 female Wistar brand albino rats with mean body mass (M:) of 247.7 g (Std. Dev[SD]: 36.59703 g) were used. The mass range was fluctuated between 165 g and 320 g. Rats' body mass could be practically a confusing factor, e.g. the more obese rats were supposed to have more pronounced UC lesions scores. This assumption was statistically investigated with grading of UC lesions findings.

Control groups
The 20 control rats with M: 252.5 g (SD: 39.31988 g) were submitted into ischemia lasting 45 min and then into reperfusion.

Erythropoietin group
The 20 Epo rats with mean mass 242.9 g (SD: 30.3105 g) were submitted into ischemia lasting 45 min and then into reperfusion on its beginning 10 mg Epol/kg body mass were IV provided.

Statistic Analysis
The bodies mass and UC lesions scores columns were compared each other by the statistic standard t-test and by the statistic Wilcoxon signed-rank test respectively ( Table 3). Any raised significant difference among UC scores, was investigated whether being due to any significant mass one. The generalized linear models (GLM) test with dependent variable the UC scores and independent variables, first the drug Epo or no drug administration, second the reperfusion time and third both the interacted variables were applied. The statistic calculations were performed by the Stata 6.0 software (Stata 6.0, StataCorp LP SA, Texas, USA).

Results
The Epo administration non-significantly declined the UC scores by (without lesions) 0.15 (-0.5595137-0.2595137) (p=0.4629). This result was accordant with the one of Wilcoxon signed-rank test (p=0.4461). The reperfusion time variable non-significantly augmented the UC scores by (without lesions) 0.05 (-0.3621388-0.4621388) (P=0.8073), nearly in accordance with one of Wilcoxon signed-rank test 0.25 (-0.773256-0.273256) (P=0.2043). However, the interaction of Epo administration with reperfusion time non-significantly declined the UC scores by (without lesions) 0.0090909 (-0.2577992-0.2396174) (p=0.9414). The co-evaluation of the above results and Table 3, yields the Tables 4 and 5 regarding the declining influence of Epo vs reperfusion time.
Considering the rats' weight as a more independent variable of GLM, a non-significant correlation appeared (p=0.5769). Table 4 The alteration influence of erythropoietin in connection with reperfusion time.

Discussion
The contribution of ischemia in UC is investigated. Salas postulated [3] that secondary compressing of cerebral congestion by the large uterus, diverts blood to the brain, causing eclamptic convulsions. Surcel et al. showed that uterus fibroma has always been accompanied by pelvic congestion inducing [4] experimentally estrogen tumors in animals. Douglas observed liver and renal glomerular congestion both in pregnant and non-pregnant rats producing [5] [7] the baseline characteristics of patients with α-darbepoetin, long-term heart failure and signs of marked congestion. Lagarto et al. showed [8] signs of a minimal irritation consisting of weak edema with vascular congestion into the right nostril, after 15 μl Epo administration; alike the one induced in Wistar rats brain during hypoxia. Zheng et al. got on [9] improving aortic stenosis patients' cardiac hypertrophy, pulmonary congestion and left ventricular dysfunction treating pre-operative aortic valve replacement with rhΕpο administration in a mouse model. Piloto et al. implicated the heart failure as cause of sudden death when was present [10] with brain vascular congestion; left ventricular hypertrophy and elevated hematocrit in rats. Naito et al. implicated decreased serum Epo concentration for [11] the cardiac remodeling mechanisms induced by iron deficiency anemia promoting cardiac fibrosis and lung congestion. Kiris et al. proved [12] that Epo significantly decreased (P=0.05 versus aortic IR) the focal renoglomerular necrosis, the Bowman's capsule dilatation, the tubular epithelium degeneration, the tubular epithelium necrosis, interstitial tissues inflammatory cells infiltration and the blood vessels congestion upon aortic IR in rats. Minamishima et al. associated [13] the premature mortality with pronounced venous congestion and dilated cardiomyopathy in enzyme PHD2 lack mice. Lee et al.
implicated [14] the red pulp congestion for splenomegaly in peroxiredoxins II-/-deficient mice, although healthy in appearance and fertility. Ruschitzka et al. treated [15] the acute left ventricular dilatation, vascular engorgement, pulmonary congestion and hemorrhage in polyglobulic transgenic mice overexpressing human Epo by NO synthase inhibitor. Gentz et al. implicated polycythemia 74% for [16] pulmonary congestion due to high serum Epo concentration in a llama.

Conclusion
Epo administration generally short-term non-significantly declines the UC lesions scores. Perhaps, a higher Epo dose and/or an experimental time lasting longer than 2 hours may reveal more significant efficacies.