Atrial peptides inhibit protein kinase C-mediated contraction in rat aorta

The effects of atriopeptin III on phorbol ester-induced contraction were examined in aorta from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Precontracted SHR aorta was less responsive than WKY aorta to atriopeptin III-induced relaxation. Additionally, SHR aorta had significantly greater basal and phorbol ester-stimulated protein kinase C (PKC) activity than WKY aorta. The altered PKC response as well as hyporesponsiveness to atriopeptin III in SHR aorta may contribute to an altered vascular response and to the pathogenesis of hypertension.