Systemic angiotensin II does not increase cardiac sympathetic nerve activity in normal conscious sheep

While it is well established that centrally injected angiotensin II (Ang II) has potent actions on sympathetic nervous activity (SNA) it is less clear whether peripheral Ang II can immediately stimulate SNA. In particular the contribution of cardiac sympathetic nerve activity (CSNA) to the acute pressor response is unknown. We therefore examined the effect of incremental doses of intravenous Ang II (3, 6, 12, 24 and 48 ng/kg/min each for 30 min) on CSNA in eight conscious sheep. Ang II infusions progressively increased plasma Ang II up to 50pmol/L above control levels in dose dependent fashion (p