![Figure 1. Effects of NG-L-nitro-arginine (L-NNA, x 10 sup -5 M; a), endothelial denudation (b), and propranolol (5 x 10 sup -5 M; c) on relaxation responses to isoproterenol of aortic rings precontracted with norepinephrine. (open circle) denotes the ring without any treatments (control). (closed circle, closed square), and [diamond] denote the rings treated with L-NNA, endothelial denudation, and propranolol, respectively. All Data represent mean +/- standard error of the means of seven separate experiments. *P < 0.05 versus control. **P < 0.001 versus control.](https://asa2.silverchair-cdn.com/asa2/content_public/journal/anesthesiology/85/5/10.1097_00000542-199611000-00022/2/22ff1.png?Expires=1716905735&Signature=wzAvySX8t~YLseD5F3-vzLPtT4a30QTJ~jzStl3ykrQhfj1V6dH8UnBzIHBA0DetgLm98SyR574KBG6lIQe6yVlazUmPDozDH0afva2JAksxmJHLTq9bPJ-6ybxrUjJmjse9HswIMARVKkrAx3EBeKloqn4pmWa4eIuyzI5AL8nDq~zEzxS6hqhJznkl7uaDlSgTuARRroUXKfe6we1HhpQvW5S2W3YMUIrcs9qnyLlf-Qz~m97ptrr5ymXLvB8f8yLbfR1QS6EAJLCWw0kbW~sJhMxnrzvQim8O6zs0G~3Dcl4N0HPZNUbPKO~zk00HK9Y2J2veMTbWCPY0PygIuA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Figure 1. Effects of NG-L-nitro-arginine (L-NNA, x 10 sup -5 M; a), endothelial denudation (b), and propranolol (5 x 10 sup -5 M; c) on relaxation responses to isoproterenol of aortic rings precontracted with norepinephrine. (open circle) denotes the ring without any treatments (control). (closed circle, closed square), and [diamond] denote the rings treated with L-NNA, endothelial denudation, and propranolol, respectively. All Data represent mean +/- standard error of the means of seven separate experiments. *P < 0.05 versus control. **P < 0.001 versus control.
