ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Tetracycline administration increases collagen synthesis in osteoblasts of streptozotocin-induced diabetic rats: A quantitative autoradiographic study (1992)

Sasaki, Takahisa ; Ramamurthy, Nungavaram S. ; Golub, Lorne M.

Springer

Calcified tissue international 50 (1992), S. 411-419

add to mindlist on the mindlist

Details

ISSN: 1432-0827

Keywords: Diabetes ; Tetracycline ; Osteoblast ; Autoradiography

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine , Physics

Notes: Summary Streptozotocin-induced, insulin-deficient diabetic rats were administrated either minocycline (MC) or a chemically modified non-antimicrobial tetracycline (CMT) by oral gavage for a 3-week period; untreated diabetic and nondiabetic rats served as controls. On day 21, all rats received an intravenous injection of 3H-proline followed by perfusion fixation with an aldehyde mixture at 20 minutes and 4 hours after isotope injection. The parietal bones of these rats were dissected and processed for quantitative electron microscopic autoradiography to study 3H-proline utilization by osteoblasts. At 20 minutes after 3H-proline injection, radioprecursor was incorporated by the Golgi-RER system of the osteoblasts in the periosteal surface of the control rats. At the 4-hour time period, most of the label was present over the collagen fibers of the osteoid. In contrast, the flattened bone-lining cells in the untreated diabetic rats showed minimal uptake (20 minutes) and secretion (4 hours) of labeled proline. In both MC and CMT-treated diabetic rats, the radioprecursor was localized in the osteoblasts and osteoid matrix in a pattern similar to that seen in the control rats at both 20 minutes and 4 hours after isotope injection. Labeling of the osteoid by the radioprecursor was greater as a result of CMT treatment than during minocycline treatment. These results suggest that the diabetes-induced suppression of synthesis and secretion of protein (presumably collagen and its precursor) by osteoblasts can be restored to near-normal levels by administration of tetracycline(s) and that this effect is mediated by a non-antimicrobial property of these antibiotics.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00296771

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Inhibition of epiphyseal cartilage collagenase by tetracyclines in low phosphate rickets in rats (1988)

Greenwald, Robert A. ; Simonson, Barry G. ; Moak, Susan A. ; [et al.]

Hoboken, NJ [u.a.] : Wiley-Blackwell

Journal of Orthopaedic Research 6 (1988), S. 695-703

add to mindlist on the mindlist

Details

ISSN: 0736-0266

Keywords: Collagenase ; Cartilage ; Rickets ; Tetracyclines ; Epiphyseal plate ; Life and Medical Sciences

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Medicine

Notes: Drugs in the tetracycline family can inhibit mammalian tissue collagenase both in vitro and in vivo by a mechanism that is independent of antibiotic action. The epiphyseal cartilages of rachitic rats contain extremely high levels of collagenase (CGase), and we have used this model to study further the phenomenon of tetracycline inhibition of tissue CGase. Rickets was induced in rats by phosphate/vitamin D deficiency and parameters of gross bone morphology, bone chemistry, and serum chemistry were evaluated in both rachitic and nonrachitic animals with and without treatment with oral tetracyclines (TETs). Minocycline (or doxycycline) partially suppressed the appearance of many of the expected changes in the rachitic animals, including gross bone hardness, growth plate widening, long bone length, suppression of weight gain, and decreased bone ash content. The effects were dose dependent and were associated with marked suppression of the enhanced CGase activity. Examination of collagen breakdown products by SDS-PAGE documented that the rachitic enzyme behaved like other mammalian collagenases including in vitro inhibition with minocycline 10-20 μg/ml and with a nonantibiotic tetracycline. No evidence of TET osseous toxicity was noted, and, in fact, administration of TET to nonrachitic animals had a mildly favorable effect on growth and development. TET suppression of CGase can be demonstrated in a well defined model system and this form of pharmacologic enzyme inhibition can be a useful probe for delineating the role of the enzyme in connective tissue pathology.

Additional Material: 3 Ill.