title: The Impact of Different Amounts of Calcium Intake on Bone Mass and Arterial Calcification in Ovariectomized Rats.
abstract: Reduced estrogen secretion and low calcium (Ca) intake are risk factors for bone loss and arterial calcification in female rodents. To evaluate the effects of Ca intake at different amounts on bone mass changes and arterial calcification, 8-wk-old female Wistar rats were randomly placed in ovariectomized (OVX) control and OVX with vitamin D3 plus nicotine (VDN) treatment groups. The OVX with VDN rats were then divided into six groups to receive different amounts of Ca in their diets: 0.01%, 0.1%, 0.3%, 0.6%, 1.2%, or 2.4% Ca. After 8 wk of administration, low Ca intake groups with 0.01% and 0.1% Ca diets had significantly reduced bone mineral density (BMD) and bone mechanical properties as compared with those of the other groups, whereas high Ca intake groups with 1.2% and 2.4% Ca diets showed no differences as compared with the 0.6% Ca intake group. For both the 0.01% and 2.4% Ca intake groups, Ca levels in their thoracic arteries were significantly higher as compared with those of the 0.6% Ca diet group, and that was highly correlated with serum PTH levels. An increase in relative BMP-2 mRNA expression in the arterial tissues of the 0.01% and 2.4% Ca diet groups was also observed. These results suggested that extremely low Ca intake during periods of estrogen deficiency may be a possible risk for the complications of reduced BMD and arterial calcification and that extremely high Ca intake may promote arterial calcification with no changes in BMD.
authors.affiliation: Institute of Health and Sport Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba.
authors.forename: Umon
authors.initials: U
authors.lastname: Agata
authors.forename: Jong-Hoon
authors.initials: JH
authors.lastname: Park
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hattori
authors.forename: Yuki
authors.initials: Y
authors.lastname: Aikawa
authors.forename: Yuya
authors.initials: Y
authors.lastname: Kakutani
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ezawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Akimoto
authors.forename: Naomi
authors.initials: N
authors.lastname: Omi
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000652:urine; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000097:blood; D003404:Creatinine / Q000652:urine; D005260:Female; D009538:Nicotine / Q000008:administration & dosage / Q000097:blood; D010052:Ovariectomy; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood / Q000652:urine; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D061205:Vascular Calcification / Q000503:physiopathology*
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D002762:Cholecalciferol; D010758:Phosphorus; D009538:Nicotine; D003404:Creatinine