Figure 2.
Effect of l-NAME and l-NNA on ACh-induced relaxation and hyperpolarization. Tracings of recordings of isometric tension (mN) and membrane potential (mV) recorded simultaneously in (a) carotid artery rings under control conditions, (b) treated with l-NAME (3 × 10−5 M), or (c) treated with the combination of l-NAME (3 × 10−5 M) and l-NNA (3 × 10−4 M). The rings were depolarized and contracted with phenylephrine (PE) (1–3 × 10−6 M) and then exposed to cumulative increasing ACh concentrations (−log M) indicated by the arrows.