Table 1.
Physical characteristics, exercise performance, and cardiac estrogen receptor gene expression.
| SHR Mean ± SEM |
WKY Mean ± SEM |
Strain p-value |
E2 p-value |
Strain × E2 p-value |
|
|---|---|---|---|---|---|
| Body Weight (g) | 0.0228 | 0.0001 | 0.471 | ||
| Intact | 194.5 ± 11.3 | 212.4 ± 7.2 | |||
| OVX | 248.7 ± 9.5* | 281.5 ± 10.5† | |||
| Heart Weight (g) | 0.736 | 0.01 | 0.376 | ||
| Intact | 0.84 ± 0.07 | 0.90 ± 0.05 | |||
| OVX | 1.04 ± 0.03 | 1.01 ± 0.03 | |||
| Tibial Length (cm) | 0.013 | 0.003 | 0.013 | ||
| Intact | 3.37 ± 0.02 | 3.37 ± 0.04 | |||
| OVX | 3.40 ± 0.04 | 3.60 ± 0.04† | |||
| HW/TL (mg/cm) | 0.871 | 0.029 | 0.147 | ||
| Intact | 2.47 ± 0.21 | 2.67 ± 0.13 | |||
| OVX | 3.05 ± 0.09 | 2.80 ± 0.08 | |||
| Uterine Weight (g) | 0.266 | 0.0001 | 0.252 | ||
| Intact | 1.16 ± 0.16 | 0.90 ± 0.13 | |||
| OVX | 0.11 ± 0.02‡ | 0.12 ± 0.01† | |||
| Exercise Capacity (meters) | 0.155 | 0.067 | 0.131 | ||
| Intact | 1,487 ± 94 | 1,464 ± 362 | |||
| OVX | 697 ± 217 | 1380 ± 46 | |||
| ERβ mRNA | 0.078 | 0.0009 | 0.038 | ||
| Intact | 1.27 ± 0.10 | 0.75 ± 0.09 | |||
| OVX | 1.49 ± 0.11 | 1.54 ± 0.22† | |||
| GPER mRNA | 0.117 | 0.0001 | 0.003 | ||
| Intact | 0.80 ± 0.09 | 0.61 ± 0.12 | |||
| OVX | 0.99 ± 0.08 | 1.54 ± 0.15‡ |
Treadmill exercise capacity was measured in SHR and WKY rats at experiment week 8. Body and tissue weights and tibia length, and estrogen receptor gene expression were obtained 10 weeks after OVX or sham (gonads left intact) procedures. The groups consisted of intact-SHRs (n = 6), OVX-SHRs (n = 6), intact-WKY (n = 5), OVX-WKY (n = 4). Using a two-way ANOVA, significant differences in functional, structural, and hemodynamic indices, with respect to strain, estrogen (E2) status (intact versus OVX), and strain × E2 status, were determined. The p-values are presented on the right of the table. For convenience, significant differences are indicated in bold. Post-hoc analysis using Tukey’s multiple comparisons indicate significant differences within-strain for estrogen status.
p < .01 OVX-SHRs versus intact-SHRs;
p < .01 OVX-WKY versus intact-WKY;
p < .001 OVX-SHRs versus intact-SHRs.
ANOVA: analysis of variance; ERβ: estrogen receptor beta; GPER: G-protein coupled estrogen receptor; HW/TL: heart weight-to-tibia length ratio; OVX: ovariectomy; SHR: spontaneously hypertensive rat; WKY: Wistar-Kyoto.