Table 2. Age, bodyweight, and mesenteric artery dimensions and vascular reactivity for 12 month old wild-type (Rln +/+) and relaxin-deficient (Rln −/−) mice.
| Rln +/+ | N | Rln −/− | N | |
| Age (months) | 12.63±0.09 | 22 | 12.51±0.09 | 18 |
| Body weight (g) | 35.99±0.74 | 19 | 35.15±0.83 | 17 |
| Stress- Strain K-value | 5.04±0.26 | 8 | 5.40±0.32 | 6 |
| Baseline OD (µm) | 143.2±5.3 | 9 | 142.1±9.3 | 9 |
| Baseline ID (µm) | 114.5±5.1 | 9 | 116.0±7.9 | 9 |
| Baseline WT (µm) | 14.3±0.8 | 9 | 13.1±0.9 | 9 |
| Baseline length (µm) | 929.5±104.1 | 9 | 812.7±111.8 | 9 |
| Baseline volume (µm3) | 921.9±85.5 | 8 | 229.2±223.1 | 9 |
| Hi K Emax (mN/mm) | 8.96±0.38 | 14 | 8.57±0.56 | 14 |
| PE Emax (% Hi K) | 112.4±3.9 | 9 | 124.5±2.9* | 10 |
| PE Emax (denuded) (% Hi K) | 121.8±6.5 | 7 | 131.5±7.6 | 6 |
| U46619 Emax (% Hi K) | 125.4±4.4 | 8 | 132.3±4.9 | 5 |
| U46619 Emax (denuded) (% Hi K) | 132.8±7.1 | 5 | 137.3±8.1 | 4 |
| ACh Rmax (%) | 85.54±3.75 | 8 | 92.56±2.13 | 7 |
| ACh (+ Indo) Rmax (%) | 77.07±4.03 | 8 | 89.75±4.25 | 6 |
| ACh (+ L-NAME & Indo) pD2 | 6.87±0.28 | 6 | 6.26±0.13 | 5 |
| ACh (+ L-NAME & Indo) Rmax (%) | 45.99±11.49 | 6 | 49.38±5.72 | 6 |
| ACh (+Indo & T34&Apa) pD2 | 6.77±0.26 | 5 | 6.40±0.26 | 5 |
| ACh (+ Indo & T34&Apa) Rmax (%) | 38.21±4.46 | 5 | 42.45±10.72 | 5 |
| ACh (+Indo, L-NAME& T34&Apa) pD2 | N/D | 5 | N/D | 6 |
| ACh (+Indo, L-NAME & T34&Apa) Rmax (%) | 6.91±6.91 | 5 | 3.70±1.78 | 6 |
| SNP Rmax (%) | 99.70±0.67 | 9 | 101.10±0.75 | 7 |
| L-NAME induced contraction | 35.47±6.67 | 7 | 30.81±4.51 | 5 |
Baseline (at 5 mmHg) artery dimensions: outer diameter (OD), inner diameter (ID) and wall thickness (WT). Vascular reactivity data: phenylephrine (PE); acetylcholine (ACh); 100 mM potassium PSS (Hi K); nitric oxide synthase inhibitor (L-NAME); indomethacin (Indo); 1-[(2-chlorophenyl) (diphenyl) methyl]-1H-pyrazole and apamin (T34 & Apa); maximum response (Emax); maximum relaxation (Rmax); pD2 sensitivity (−log EC50); N/D not determined. All values are expressed as mean ± SEM and N refers to the sample size. * significantly (P<0.05) greater than Rln +/+ mice.