Asymmetric dimethylarginine is not involved in ovariectomy-induced osteopenia in rats.
Previous studies have indicated that the plasma concentration of nitric oxide synthase inhibitor, asymmetric dimethylarginine (ADMA), was increased in postmenopausal women. In the study reported here, we tested the relationship between the decrease of bone mineral density (BMD) and ADMA concentration in ovariectomized (OVX) rats. Ovariectomized rats at 8 months of age were treated with 17beta-estradiol (10 or 30 microg/kg of body weight/day, s.c.) or L-arginine (300 mg/kg/day, i.p.) for 12 weeks (n = 10 for each group). Pre- and posttreatment total BMD, posttreatment plasma nitrite/nitrate and ADMA concentrations, and posttreatment BMD in the lumbar part of the spine (L4-L6), femurs, and tibias were examined. Ovariectomy caused a significant decrease in several BMD indexes, which was reversed by estrogen treatment (P < 0.05). Plasma nitrite/nitrate concentration was significantly decreased in OVX rats, but was restored by estrogen treatment (P < 0.05). There were no differences in the plasma concentration of ADMA in OVX or estrogen-treated rats. L-Arginine had no effect on plasma nitrite/nitrate concentration and BMD in OVX rats. These results suggest that ovariectomy does not influence the plasma concentration of ADMA, and that ADMA is not involved in ovariectomy-induced osteopenia in rats.
Peng
Wei-Jie
WJ
Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410078, China.
Jiang
Jun-Ling
JL
Jia
Su-Jie
SJ
Li
Dai
D
Zhang
Xiao-Jie
XJ
Luo
Dan
D
Liao
Er-Yuan
EY
Deng
Han-Wu
HW
Li
Yuan-Jian
YJ
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000097:blood / Q000209:etiology; D001842:Bone and Bones / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D009566:Nitrates / Q000097:blood; D009573:Nitrites / Q000097:blood; D010052:Ovariectomy / Q000009:adverse effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D004967:Estrogens; D009566:Nitrates; D009573:Nitrites; C487735:dimethylarginine; D001120:Arginine