Table 2

Potency (pEC502-a) and maximal effect (Emax) values for ET-1 in human cardiac tissues

TissuenBasal forcepEC50EmaxEmax
mN mN % Ca2+b
Right atrium (non-βB2-c)184.3  ± 1.08.0  ± 0.112.3  ± 1.847.0  ± 3.5
Right atrium (βB)286.2  ± 1.18.0  ± 0.113.7  ± 1.552.0  ± 3.9
Right atrium (heart failure)73.9  ± 1.67.8  ± 0.18.2  ± 2.039.8  ± 6.2
Left atrium (heart failure)32.0  ± 0.87.8  ± 0.13.2  ± 1.117.0  ± 4.2
Right ventricle (heart failure)510.6  ± 2.17.8  ± 0.113.1  ± 2.814.5  ± 5.5

Values are means ± S.E. from n patients. There were no differences in basal values for atrial groups (P = .3).

  • ↵2-a −Log EC50.

  • 2-b Maximal response expressed as a percentage of the response to 9.25 mM Ca2+.

  • ↵2-c βB, β-blocker-treated patients.