ABSTRACT
Objective To explore the relationship betw een injury age and expressions of erythropoietin (EPO ) and its receptor EPO R in the brain tissue of rats after cerebral injury. Methods Seventy-tw o rats w ere random ly divided into control group (36 rats) and cerebral injury group (36 rats). The rats w ere sac-rificed at 1, 2, 4, 8, 12, 24 h after cerebral injury (6 rats at each tim e point) and the brain tissues w ere extracted. The expressions of m RNA and protein of EPO and EPO R at different tim e points w ere de-tected by real-tim e fluorescent quantitative PC R and W estern bloting. Results The expressions of EPO and EPO R increased w ithin 24 h after injury. The expressions of m RNA and protein of EPO w ere relat-ed to the injury age, and the correlations w ere 0.875, 0.911, respectively (P<0.05). The expressions of m RNA and protein of EPO R w ere related to the injury age, and the correlation coefficients w ere 0.936, 0.905, respectively (P<0.05). Conclusion The expressions of EPO and EPO R increase gradually in the early stage of the rat’s cerebral injury, w hich are associated w ith the injury age and could be a useful value for estim ating injury age.
ABSTRACT
Objective To examinewhether cyclosporine A (CsA) treatment can induce anemia and changes in expression of erythropoietin (EPO) and its receptor (EPOR) in renal tissues of rats with chronic CsA nephrotoxicity. Methods Sprague-Dawley rats were treated daily with subcutaneous injection of vehicle (olive oil, 1 mL/kg, control group) or CsA (15 mg/kg, CsA nephrotoxicity model group) for 4 weeks. The renal function and hemoglobin (Hb) and hematocrit (Hct) levels were analyzed by Automatic Biochemistry Analyzer in the two groups. Masson Trichrome staining was used to examine the extent of tubulointerstitial fibrosis. Immunohistochemistry and Western blotting analysis were used to examine the expression of EPO and EPOR protein. And cell apoptosis was observed by TUNEL assay and electron microscope. Results Compared with the control group, CsA nephrotoxicity group showed renal insufficiency, tubulointerstitial fibrosis, and significantly more apoptotic cells (P<0.01). Meanwhile, CsA nephrotoxicity group also had anemia, manifested by significantly decreased Hb and Hct levels (P<0.01). Immunohistochemistry and Western blotting analysis showed that CsA treatment significantly decreased EPO expression and significantly increasedEPOR expression compared with the control group (P<0.01). Furthermore, we also found that EPO protein expression was negatively associated with tubulointerstitial fibrosis (r=-0. 729, P<0.001) and the number of TUNEL-positive cells (r=-0.841, P<0.001). Conclusion Renal EPO expression is decreased in rats with chronic CsA nephrotoxicity, which resulting in anemia; and tubularepithelial cell apoptosis induced by CsA is related to decrease of EPO protein.