Fig. 1.

Administration of AVP promotes the expression of IL-6 mRNA and protein in murine hearts. Animals were administered 0.5 U/kg AVP or 0.9% NaCl as vehicle via the tail vein. Total RNA and protein lysates were isolated from the myocardium of the left ventricle to measure IL-6 mRNA at 6 h after the administration of AVP. a, b AVP induced the elevation of IL-6 mRNA and protein levels in the rat myocardium. ELISA for IL-6 protein and qPCR for IL-6 mRNA were performed in triplicate to ensure the reliability of the individual values. c, Deletion of β-arrestin 2 reduced the AVP-induced IL-6 elevation in the mouse myocardium. The upper panels in (a, c) are representative images of the qPCR products, and the lower panels show the data expressed as the means ± SEM of four (rats) or five (mice) separate experiments. *P < 0.05, **P < 0.01, ***P < 0.001 vs. vehicle, ^##P < 0.01