Response of forearm blood flow to local intra-arterial infusion of ET-1; mean percentage change in forearm blood flow ratio (infused arm:noninfused arm), forearm blood flow (infused arm) and forearm blood flow (noninfused arm), ± s.e. mean for all; (2.5 pmol min−1; visit 1, s; visit 2, d and 10 pmol min−1; visit 1, □; visit 2, ▪).