Erythropoietin Reverses Sepsis-Induced Vasoplegia to Norepinephrine Through Preservation of α1D-Adrenoceptor mRNA Expression and Inhibition of GRK2-Mediated Desensitization in Mouse Aorta.

We investigated the effect of erythropoietin (EPO) posttreatment on survival time and vascular functions in a mouse model of sepsis. Sepsis was induced by cecal ligation and puncture. After 20 ± 2 hours of sepsis, thoracic aorta was isolated for assessing its reactivity to norepinephrine (NE) and acetylcholine (ACh). We also measured the tissue nitric oxide (NO) level, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), G protein-coupled receptor kinase 2 (GRK2), and α1D adrenoceptor messenger RNA (mRNA)/protein expression. In septic mice, EPO moderately improved the survival time from 19.68 ± 0.75 to 34.7 ± 3.2 hours. Sepsis significantly decreased the aortic contractile response to NE along with reduced α1D mRNA and protein expression. Erythropoietin significantly preserved the α1D receptor expression and restored NE-induced contractions to control levels in septic mice. Further, it attenuated the aortic α1D receptor desensitization in sepsis which was evident from reduced ...