Effect of endothelial cell (EC) presence or absence on response of isolated aortic ring segments to βAR agonist isoproterenol (ISO)
| Relaxation to ISO (Emax) | LogEC50 | P Value | |
|---|---|---|---|
| % | Log M | ||
| +EC | |||
| NLC | −95 ± 2 | −7.1 ± 0.1 | 0.0655 |
| GRK2-25 | −79 ± 4 | −6.5 ± 0.2 | |
| −EC | |||
| NLC | −73 ± 2 | −6.3 ± 0.1 | 0.0231 |
| GRK2-25 | −62 ± 5 | −5.7 ± 0.1 |
Maximal vessel relaxation by 10 μM isoproterenol (E max) was determined after precontraction by phenylephrine. Concentrations of isoproterenol that caused 50% relaxation were determined by nonlinear regression analysis (log EC50). Data shown are means ± S.E.M. for three vessels for NLC and four vessels for GRK2-25. Statistical analysis was performed using unpaired, two-tailed t-test.