Table 3.
Effects of in vivo lipopolysaccharide (LPS) on left ventricular skinned fibers of young rats and senescent rats
| Young rats (3 months old) | Senescent rats (24 months old) | ||||
| Control group (n = 4 rats, n = 23 fibers) | LPS 0.5 mg/kg group (n = 4 rats, n = 23 fibers) | LPS 5 mg/kg group (n = 5 rats, n = 22 fibers) | Control group (n = 4 rats, n = 22 fibers) | LPS 0.5 mg/kg group (n = 5 rats, n = 20 fibers) | |
| Resting tension (mN/mm2) | 3.2 ± 0.5 | 3.4 ± 0.4 | 3.7 ± 0.6 | 6.6 ± 0.5 | 4.4 ± 0.4* |
| Maximal active tension (mN/mm2) | 47.4 ± 3.8 | 54.4 ± 3.3 | 51.5 ± 7.6 | 43.0 ± 3.2 | 41.8 ± 4.2 |
| pCa50 (pCa units) | 5.81 ± 0.04 | 5.69 ± 0.04* | 5.67 ± 0.04* | 5.58 ± 0.03 | 5.53 ± 0.03 |
| Hill coefficient | 1.60 ± 0.12 | 1.66 ± 0.11 | 1.58 ± 0.09 | 1.43 ± 0.09 | 1.57 ± 0.10 |
Values are the mean ± standard error of the mean. pCa50, Ca2+ concentration for half-maximal tension, expressed in pCa units (with pCa = -log[Ca2+]). *P < 0.05 versus respective control (saline-injected) group.