Linked Life Data

15856362

Source:http://linkedlifedata.com/resource/pubmed/id/15856362

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2005-12-19
pubmed:abstractText
Reactive oxygen species (ROS) may contribute to aging and osteoporosis resulting from marked decreases in plasma antioxidants in aged osteoporotic women. On the other hand, high-dose vitamin K2 (menaquinone-4: menatrenone, MK-4) supplementation has been reported to reduce ovariectomy-induced bone loss in rats and to decrease osteoporotic fracture in postmenopausal women. However, the mechanism by which vitamin K2 prevents osteoporosis is unclear. Recently, vitamin K2 has been suggested to preserve antioxidant activity as a novel function. Therefore, we investigated the effect of vitamin K2 on the osteoporosis of aged rats by evaluating the relationships between serum antioxidant levels and bone metabolism. Aged female rats exhibited significantly lower serum alkaline phosphatase activity and osteocalcin level, together with lower serum levels of antioxidants such as 17beta-estradiol, macrophage migration inhibitory factor (MIF) and glutathione peroxidase (GPx) activity, as compared with young female rats. On the other hand, vitamin K2 supplementation (500 mg/kg, food intake) for 98 days led to a significantly increased serum vitamin K2 level (3,045+/-915 ng/ml in the vitamin K2 supplemented group vs. 4.6+/-3.4 ng/ml in the control diet group; P<0.0001) with increased serum alkaline phosphatase activity and MIF level (P<0.05). Unexpectedly, however, it failed to increase the serum level of antioxidants such as GPx. Nor did it affect bone metabolism markers such as osteocalcin and osteopontin, which were significantly lower than in the young female rats (P<0.05). Finally, the histomorphometric properties of the proximal tibia in the femur were not altered by vitamin K2. These results suggest that high-dose vitamin K2 supplementation neither improves lowered antioxidant levels nor stimulates bone formation in aged rats.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0937-941X
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1604-10
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15856362-Age Factors, pubmed-meshheading:15856362-Alkaline Phosphatase, pubmed-meshheading:15856362-Animals, pubmed-meshheading:15856362-Antioxidants, pubmed-meshheading:15856362-Biological Markers, pubmed-meshheading:15856362-Bone and Bones, pubmed-meshheading:15856362-Calcium, pubmed-meshheading:15856362-Dietary Supplements, pubmed-meshheading:15856362-Female, pubmed-meshheading:15856362-Glutathione Peroxidase, pubmed-meshheading:15856362-Osteocalcin, pubmed-meshheading:15856362-Osteoclasts, pubmed-meshheading:15856362-Osteopontin, pubmed-meshheading:15856362-Osteoporosis, pubmed-meshheading:15856362-Phosphorus, pubmed-meshheading:15856362-Rats, pubmed-meshheading:15856362-Rats, Wistar, pubmed-meshheading:15856362-Sialoglycoproteins, pubmed-meshheading:15856362-Vitamin K 2, pubmed-meshheading:15856362-Weight Gain
pubmed:year
2005
pubmed:articleTitle
The effect of vitamin K2 on bone metabolism in aged female rats.
pubmed:affiliation
Department of Biochemistry, School of Dentistry, Hokkaido University, 060-8586, Sapporo, Japan. sakamoto@den.hokudai.ac.jp
pubmed:publicationType
Journal Article