Myocardial IL-6 regulation by neurohormones—an in vitro superfusion study

Background: Interleukin-6 (IL-6) is expressed in the myocardium and has been implicated in cell proliferation, negative inotropic effects and myocardial hypertrophy. To determine whether myocardial IL-6 is modified by neurohumoral and immunoregulatory stimuli, we studied the effects of lipopolysaccharide (LPS), corticosterone (CS), isoproterenol and angiotensin II on myocardial IL-6 secretion in superfused myocardium. Methods: Slices of rat left ventricular myocardium were superfused in 80 μl chambers for up to 5 h. LPS (1, 50, and 100 μg/ml), CS (10 −7, 10 −6, and 10 −5 M, DSMO as vehicle), isoproterenol (10 −6, 10 −7, and 10 −8 M) and angiotensin II (10 −5, 10 −7, and 10 −9 M) were added to the culture medium at hour 2. IL-6 was measured in the perfusate by ELISA. Results: Physiological corticosterone concentrations (10 −7 M) resulted in an increase in IL-6 concentration (142%) while high doses of steroid decreased IL-6 significantly (CS 10 −6 M: 88±14%, p