Related Experiment Video
Updated: Sep 3, 2026
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Effects of anastrozole on lipid metabolism compared with tamoxifen in rats
Yasuo Hozumi1, Yoji Hakamata, Hideki Sasanuma
1Department of Surgery, Jichi Medical School, Tochigi, Japan. y-hozumi@jichi.ac.jp
Background:
Anastrozole, a new aromatase inhibitor, has been used to treat postmenopausal metastatic breast cancer, and several clinical trials of adjuvant treatment using this agent are ongoing. However, the effects of anastrozole on lipid metabolism are unknown. The aim of this study was to evaluate the effect of anastrozole on lipid metabolism, especially lipoprotein lipase (LPL) activity, compared with tamoxifen in rats.
Methods:
Ovariectomized female rats were divided into six groups: C, controls; T, tamoxifen treatment; A, anastrozole treatment; CAT, combined anastrozole/tamoxifen treatment; NAT, no treatment after tamoxifen; and AAT, anastrozole treatment after tamoxifen. The agents were orally administered for 3 weeks. Serum total cholesterol, triglycerides, and LPL activity in postheparin plasma were measured at the end of the experiment.
Results:
Serum cholesterol levels were significantly lower in the T and CAT groups than in controls (P < 0.001). Serum triglyceride levels were significantly higher in the T group than in the other groups (P < 0.001). LPL activity was significantly lower in T and AAT groups (P < 0.01). There was no significant difference in any parameters in group A.
Conclusions:
Anastrozole does not affect lipid metabolism including LPL activity. There was little effect on lipid profiles during combination treatment or following treatment with tamoxifen. In a clinical setting, therefore, anastrozole might be safe for patients with abnormal triglyceride profiles during tamoxifen treatment.
Insights
Anastrozole does not impact lipid metabolism or lipoprotein lipase activity in rats. This suggests anastrozole may be safe for breast cancer patients with abnormal triglyceride levels during tamoxifen treatment.
Area of Science:
- Endocrinology and Metabolism
- Oncology
- Pharmacology
Background:
- Anastrozole is an aromatase inhibitor used for postmenopausal metastatic breast cancer.
- Its effects on lipid metabolism, particularly lipoprotein lipase (LPL) activity, are not well understood.
- This study aimed to compare anastrozole's effects on lipid metabolism with tamoxifen in a rat model.
Purpose of the Study:
- To evaluate the impact of anastrozole on lipid metabolism, focusing on lipoprotein lipase (LPL) activity.
- To compare these effects with those of tamoxifen in ovariectomized rats.
- To assess the safety of anastrozole in patients with potential lipid profile abnormalities.
Main Methods:
- Ovariectomized rats were divided into six treatment groups: control, tamoxifen, anastrozole, combined anastrozole/tamoxifen, and sequential treatments.
- Agents were administered orally for three weeks.
- Serum total cholesterol, triglycerides, and postheparin plasma LPL activity were measured.
Main Results:
- Tamoxifen significantly reduced serum cholesterol and increased triglyceride levels.
- Anastrozole treatment alone showed no significant changes in measured parameters.
- Lipoprotein lipase (LPL) activity was significantly reduced in tamoxifen and anastrozole-after-tamoxifen groups.
Conclusions:
- Anastrozole does not appear to affect lipid metabolism or LPL activity.
- Combination or sequential treatment with tamoxifen had minimal impact on lipid profiles.
- Anastrozole may be a safe option for breast cancer patients experiencing triglyceride issues with tamoxifen therapy.
