title: Free 4-hydroxyproline content in serum of bedridden aged people is elevated due to fracture.
abstract: Hydroxyproline (Hyp) content in biological fluids is used as a parameter of collagen catabolism, especially bone resorption. In this paper, we examined the relationship between aging and serum free 4-Hyp and proline (Pro) content using a newly introduced analytical technique which is chemiluminescence determination with electrogenerated tris (2,2'-bipyridine) ruthenium(III). Serum was collected from 50 bedridden aged people and 131 normal subjects living in Yamato-son, Amamioshima, Kagoshima. In the free 4-Hyp content of normal serum, the change in females is more gentle than that males with aging. The free 4-Hyp content of bedridden aged serum is significantly (p<0.05) elevated compared to normal aged serum. Bedridden aged females and males also show levels significantly (p<0.05) elevated in comparison to normal. These changes are due to bone resorption based on bedridden patients' atrophy. In bedridden aged people, free 4-Hyp of those with a fracture was significantly (p<0.05) elevated than in people without a fracture. No relationship between low bone density and high free 4-Hyp in serum was observed. It seems that bone resorption or bedridden atrophy may be enhanced in bedridden aged people by a fracture. In free Pro content in serum, no significant change was observed. These results show that the free 4-Hyp content in serum is useful in the clinical or biological inspection of bone resorption, especially in aged people.
authors.affiliation: Biochemistry Laboratory, College of Pharmacy, Nihon University, Funabashi, Chiba, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Koike
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Seo
authors.forename: I
authors.initials: I
authors.lastname: Sakurada
authors.forename: K
authors.initials: K
authors.lastname: Tezuka
authors.forename: K
authors.initials: K
authors.lastname: Uchikura
authors.forename: K
authors.initials: K
authors.lastname: Uchikawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D001510:Bed Rest; D015519:Bone Density; D001862:Bone Resorption / Q000097:blood; D002138:Calibration; D005260:Female; D050723:Fractures, Bone / Q000097:blood*; D006801:Humans; D006909:Hydroxyproline / Q000097:blood*; D007103:Immobilization; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D011392:Proline / Q000097:blood
chemical_list: D011392:Proline; D006909:Hydroxyproline