Table 2. Characteristics of the contractile responses of endothelium-denuded aortic rings to various agonists.
| Agonist | EC50 | Emax (g) |
| KCl | 8.5±1.1 mmol/L | 3.70±0.93 |
| PE | 120±30 nmol/L | 3.75±0.43 |
| AVP | 11.2±2.3 nmol/L | 3.34±0.34 |
| ET-1 | 4.4±1.5 nmol/L | 4.00±0.62 |
The agonists used are KCl, phenylephrine (PE), arginine-vasopressin (AVP), and endothelin-1 (ET-1). Results are presented as Emax, corresponding to the maximal effect elicited by each agonist expressed in terms of isometric tension (g), and EC50 values (in mmol/L or nmol/L), indicating the concentration at which 50% of the maximal effect is induced. Values represent the mean±s.e.m. of 5 animals, with experiments performed in duplicate.