Table 1.
Boltzmann parameters of ICa,L activation and inactivation in a smooth muscle cell in control (Ctr), in the presence of relaxin (RLX) alone or RLX with ODQ (ODQ + RLX), 9CPA (9CPA + RLX) and ODQ + 9CPA (ODQ + 9CPA + RLX)
| Parameters | Ctr | RLX | ODQ + RLX | 9CPA + RLX | ODQ + 9CPA + RLX |
| ICa,L/Cm (pA/pF) | 8.8 ± 0.5 | 7.2 ± 0.7a | 7.9 ± 0.6 | 8.2 ± 0.6 | 8.7 ± 0.6c |
| Vp (mV) | 17.5 ± 2 | 20.1 ± 2 | 17.9 ± 2 | 18.1 ± 1 | 17.5 ± 1.9 |
| tp (ms) | 270.8 ± 22 | 194.1 ± 19b | 230.8 ± 15ac | 244.8 ± 22c | 259.8 ± 24c |
| Va (mV) | 4.0 ± 0.3 | 8.9 ± 0.6e | 6.0 ± 0.6bc | 4.9 ± 0.5ad | 4.3 ± 0.4d |
| ka (mV) | 6.5 ± 0.4 | 6.0 ± 0.5 | 6.2 ± 0.4 | 6.4 ± 0.4 | 6.4 ± 0.4 |
| Vrev (mV) | 67.2 ± 4 | 68.8 ± 4 | 68.1 ± 5 | 67.5 ± 4 | 67.8 ± 4 |
| Vh (mV) | -14.4 ± 2 | -10.9 ± 1a | -12.4 ± 1 | -12.6 ± 2 | -14.0 ± 1c |
| kh (mV) | 7.6 ± 0.5 | 7.5 ± 0.5 | 7.6 ± 0.6 | 7.6 ± 0.7 | 7.6 ± 0.6 |
| I2h (Norm) | 0.09 ± 0.02 | 0.23 ± 0.02b | 0.14 ± 0.01ad | 0.13 ± 0.03d | 0.09 ± 0.03f |
| V2h (mV) | 22.0 ± 2 | 22.3 ± 1.9 | 21.8 ± 2.1 | 21.5 ± 2 | 21.9 ± 1.8 |
| k2h (mV) | 8.0 ± 0.7 | 6.3 ± 0.6a | 7.1 ± 0.7 | 7.5 ± 0.3c | 7.9 ± 0.2c |
In the U shaped inactivation curves (h) the best fit to the data is obtained by the sum of two Boltzmann terms whose parameters are indicated with the subscript h for the term at negative potential, and 2h for the term at positive potential; the amplitude of the normalized second term, I2h (Norm), was evaluated at 50 mV.
P < 0.05,
P < 0.01 and
P < 0.001 RLX compared to the related control;
P < 0.05,
P < 0.01 and
P < 0.001 compared to RLX. Data for Ctr ( = 67 cells, 25 strips from 12 mice), for RLX (n = 20 cells, 10 strips from 5 mice), for ODQ + RLX (n = 18 cells, 9 strips from 5 mice), for 9CPA + RLX (n = 15 cells, 8 strips from 5 mice) and for ODQ + 9CPA + RLX (n = 16 cells, 9 strips from 5 mice), RLX: Relaxin; ODQ: Oxadiazolo[4,3-a]-quinoxalin-1-one; 9CPA: 9-cyclopentyladenine.