Post by Nandi reprinted W/O permission.
These researchers set out to test the hypothesis that the conversion of testosterone to estrogen by aromatase in coronary vessel walls protects against the development of atherosclerotic plaques in males. They gave mice anastrazole for 8 weeks and compared the sizes of the atherosclerotic lesions to a control group. After only 8 weeks of therapy there was a doubling in the area of the lesions.
Proc Natl Acad Sci U S A 2001 Mar 13;98(6):3589-93
Testosterone inhibits early atherogenesis by conversion to estradiol: critical role of aromatase.
Nathan L, Shi W, Dinh H, Mukherjee TK, Wang X, Lusis AJ, Chaudhuri G.
Department of Obstetrics and Gynecology, University of California Los Angeles School of Medicine, Los Angeles, CA 90095-1740,USA.
The effects of testosterone on early atherogenesis and the role of aromatase, an enzyme that converts testosterone to estrogens, were assessed in low density lipoprotein receptor-deficient male mice fed a Western diet. Castration of male mice increased the extent of fatty streak lesion formation in the aortic origin compared with testes-intact animals. Administration of anastrazole, a selective aromatase inhibitor, to testes-intact males increased lesion formation to the same extent as that observed with orchidectomized animals. Testosterone supplementation of orchidectomized animals reduced lesion formation when compared with orchidectomized animals receiving the placebo. This attenuating effect of testosterone was not observed when the animals were treated simultaneously with the aromatase inhibitor. The beneficial effects of testosterone on early atherogenesis were not explained by changes in lipid levels. Estradiol administration to orchidectomized males attenuated lesion formation to the same extent as testosterone administration. Aromatase was expressed in the aorta of these animals as assessed by reverse transcription-PCR and immunohistochemistry. These results indicate that testosterone attenuates early atherogenesis most likely by being converted to estrogens by the enzyme aromatase expressed in the vessel wall.
These researchers set out to test the hypothesis that the conversion of testosterone to estrogen by aromatase in coronary vessel walls protects against the development of atherosclerotic plaques in males. They gave mice anastrazole for 8 weeks and compared the sizes of the atherosclerotic lesions to a control group. After only 8 weeks of therapy there was a doubling in the area of the lesions.
Proc Natl Acad Sci U S A 2001 Mar 13;98(6):3589-93
Testosterone inhibits early atherogenesis by conversion to estradiol: critical role of aromatase.
Nathan L, Shi W, Dinh H, Mukherjee TK, Wang X, Lusis AJ, Chaudhuri G.
Department of Obstetrics and Gynecology, University of California Los Angeles School of Medicine, Los Angeles, CA 90095-1740,USA.
The effects of testosterone on early atherogenesis and the role of aromatase, an enzyme that converts testosterone to estrogens, were assessed in low density lipoprotein receptor-deficient male mice fed a Western diet. Castration of male mice increased the extent of fatty streak lesion formation in the aortic origin compared with testes-intact animals. Administration of anastrazole, a selective aromatase inhibitor, to testes-intact males increased lesion formation to the same extent as that observed with orchidectomized animals. Testosterone supplementation of orchidectomized animals reduced lesion formation when compared with orchidectomized animals receiving the placebo. This attenuating effect of testosterone was not observed when the animals were treated simultaneously with the aromatase inhibitor. The beneficial effects of testosterone on early atherogenesis were not explained by changes in lipid levels. Estradiol administration to orchidectomized males attenuated lesion formation to the same extent as testosterone administration. Aromatase was expressed in the aorta of these animals as assessed by reverse transcription-PCR and immunohistochemistry. These results indicate that testosterone attenuates early atherogenesis most likely by being converted to estrogens by the enzyme aromatase expressed in the vessel wall.