Table 2 Effect of gadolinium and streptomycin on the action potential parameters of the pulmonary veins with 300‐mg stretch.
| Concentrations (μmol/l) | Gadolinium (n = 12) | p Value | Streptomycin (n = 7) | p Value | |||||
|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 3 | 10 | 0 | 10 | 40 | |||
| APA(mV) | 90 (3) | 84 (3)* | 81 (3)*† | 77 (3)*†‡ | <0.005 | 91 (2) | 82 (1)§ | 80 (2)§* | <0.005 |
| APD50 (ms) | 48 (6) | 54 (3)* | 60 (5)*† | 65 (6)*† | <0.005 | 48 (2) | 55 (2) | 62 (2)§¶ | <0.005 |
| APD90 (ms) | 109 (13) | 117 (4) | 123 (6)*† | 135 (9)*†‡ | <0.005 | 115 (3) | 119 (2.1) | 132 (3)§¶ | <0.005 |
| MDP (−mV) | 83 (4) | 75 (5)* | 71 (3)*† | 66 (4 )*†‡ | <0.005 | 83 (2) | 70 (2)§ | 68 (2)§ | <0.005 |
| Incidence of EADs (%) | 9/12 (75) | 6/12 (50) | 2/12 (17)* | 1/12 (8)* | <0.005 | 6/7 (86) | 3/7 (43) | 1/7 (14)§ | <0.005 |
| Incidence of DADs (%) | 5/12 (42) | 2/12 (17) | 0/12 (0)* | 0/12 (0)* | <0.05 | 4/7 (57) | 2/7 (33) | 0/7 (0) | 0.06 |
APA, amplitudes of the action potential; APD50, action potential at a repolarisation of 50%; APD90, action potential at a repolarisation of 90%; DADs, delayed after‐repolarisation; EADs, early after‐repolarisation; MDP, membranous diastolic potential.
Gadolinium and streptomycin were given in different groups of tissue preparations. The action potentials of the pulmonary veins were elicited by electrical stimuli (2 Hz). *p<0.05 versus 0 μmol/l gadolinium; †p<0.05 versus 1 μmol/l gadolinium; ‡p<0.05 versus 3 μmol/l gadolinium; §p<0.05 versus 0 μmol/l streptomycin; ¶p<0.05 versus 10 μmol/l streptomycin.