Difference in label length between demethylchlortetracycline and oxytetracycline: Implications for the interpretation of bone histomorphometric data |
| |
Authors: | A M Parfitt J Foldes A R Villanueva M S Shih |
| |
Institution: | (1) Bone and Mineral Research Laboratory, Henry Ford Hospital, 2799 W. Grand Blvd., E& R 7092, 48202 Detroit, MI, USA;(2) Harrington Arthritis Research Center, 1800 E.Van Buren, 85006 Phoenix, AZ, USA |
| |
Abstract: | Summary We measured the individual lengths of fluorescent labels on the three subdivisions of the endosteal envelope in iliac bone
biopsy specimens produced by the administration of both oxytetracycline and demethylchlortetracycline. Fifty-one healthy subjects
and 53 patients with postmenopausal osteoporosis were labeled in the stated order, and 8 osteopenic patients were labeled
in the reverse order. Whatever the order of administration, the demethylchlortetracycline label was longer than the oxytetracycline
label. We conclude: (1) the difference in label lengths reflects a difference between the two compounds in some intrinsic
property, whether physical, chemical, or pharmacokinetic. (2) If the calculation of extent of mineralizing surface is based
on the mean length of the two labels, a suitable correction should be applied to the shorter label; alternatively, the length
of the longer label alone should be used. (3) Unlabeled osteoid not due to label escape probably results from slow terminal
mineralization after cessation of matrix synthesis during which too few tetracycline molecules are incorporated to exceed
the threshold for visible fluorescence, rather than from the temporary interruption of mineralization followed by its resumption. |
| |
Keywords: | Tetracycline labeling Bone remodeling Bone formation rate Unlabeled osteoid Bone histomorphometry |
本文献已被 SpringerLink 等数据库收录! |
|