Comparison of the contractile responses of human coronary bypass grafts and monkey arteries to human urotensin-II

Human urotensin-II (hU-II) is a cyclic peptide recently cloned in humans an d present in human cardiac tissue and human arteries. The effects of hU-II were studied on human coronary bypass grafts in vitro. In three out of eigh t human mammary arteries, and two out of three human radial arteries, hU-II caused contraction; human saphenous veins did not respond to hU-II. When i t exists, the contraction slowly develops and has a low-to-moderate intensi ty. All radial arteries obtained from young healthy non-human primates cont racted strongly to hU-II.