“…There is heterogeneity of sympathetic nerve distribution (Holmgren et al, 1985), tissue noradrenaline content (Petch & Naylor, 1979;Pierpont et al, 1984;Verhoeven et al, 1991), and P-adrenoceptors (Baker et al, 1980;Baker & Sheets, 1982;Brodde et al, 1982;Upsher & Weiss, 1989) in the left ventricular free wall. Sympathetic nerves enter the left ventricle through the basal region of the subepicardium (Angelakos, King & Millard, 1969;Holmgren et al, 1985). While adenylyl cyclase activity tended to be slightly higher in the base than in the apex, there were no significant differences in adenylyl cyclase or flow activity in any region.…”