The purpose of this study was to determine the effects of estrogen deficiency and hormone replacement on the biomechanical properties of rat saphenous artery. Adult virgin Sprague-Dawley rats were pharmacologically ovariectomised by 750 μg/kg triptorelin im. every 4th week and received either 450 μg/kg estradiol propionate (10 animals) or its vehicle (10 animals) im. every week. Ten other animals were not ovariectomised, only the vehicle was administered for the same periods of time (control group). After 12 weeks of treatment, cylindrical segments of the saphenous artery were isolated and cannulated at both ends. Pressure-diameter curves in the range of 0-200 mmHg were recorded from segments in normal KR, with norepinephrine (1.58×10-5M), and then with papaverine (2.84×10-5M). Pharmacological ovariectomy decreased, estrogen replacement increased significantly the passive diameter of the arteries (internal radius at 100 mmHg IP:340±3μm vs. 300±9μm in the estrogen treated and untreated group, respectively, p<0.05). Decreased reactivity to norepinephrine was also restored by estrogen treatment (active strain at 100 mmHg IP: -49.2±1.3% vs. -54.6±0.4%, p<0.05). It is concluded that estrogen replacement reverses the long-term effects of ovariectomy on the biomechanical properties of small arteries.
|Publication status||Published - dec. 1 1997|
ASJC Scopus subject areas
- Molecular Biology