Popis: |
Endothelin (ET)-1, the most potent mammalian vasoconstrictor identified to date, was originally characterized as a peptide capable of producing contractile responses that were both sustained and extremely resistant to wash-out (Yanagisawa et al. 1988). Subsequently, ET-1 has been shown to contract both resistance arterioles and venous tissue in addition to conduit arteries (venous tissue generally being more sensitive than arterial vessels; Brain et al. 1988, 1989; Borges et al. 1989b; Cocks et al. 1989; D’Orleans-Juste et al. 1989). Furthermore, since subthreshold concentrations of ET-1 augment the contractile actions of norepinephrine, 5-HT, and angiotensin II, it has been proposed that ET-1 also sensitizes vessels to the actions of other “classical” circulating neurohumoral factors (MacLean and McGrath 1990; Lerman et al. 1991; Nakayama et al. 1991). |