Plasma cardiotrophin-1 is elevated in human hypertension and stimulated by ventricular stretch

Cardiotrophin-1 (CT-1) is an interleukin-6-related cytokine with known hypertrophic and protective actions upon cardiac myocytes. We provide here the first report of cardiac tissue and plasma levels of CT-1 in human and experimental hypertension, demonstrate cardiac CT-1 secretion stimulated by ventricular stretch, and characterise molecular forms of CT-1 in tissue and plasma. CT-1 levels in human and rat plasma and in rat cardiac tissue extracts were determined by specific radioimmunoassay (RIA). Cardiac CT-1 secretion during ventricular stretch was studied in isolated, perfused hearts. Molecular forms of CT-1 were identified using RIA coupled with high performance liquid chromatography (HPLC). Results are given as mean+/-SEM. Plasma levels of CT-1 in patients with untreated hypertension (UTH, 606+/-18 pmol/L, n=24) were significantly higher than those in age-and BMI-matched normotensive volunteers (NT, 546+/-12 pmol/L, n=31, P