Opposing effects of diabetes and tetracycline on the degradation of collagen membranes in rats.
BACKGROUND
Increased collagenolytic activity, characteristic of uncontrolled diabetes, may compromise collagen membrane (CM) survival. Tetracycline (TCN) possesses anticollagenolytic properties and delays CM degradation in healthy animals. This study evaluates the degradation of TCN--immersed and -non-immersed CMs in rats with diabetes compared to those with normoglycemia.


METHODS
Diabetes was induced in 15 12-week-old male Wistar rats by injection of 65 mg/kg streptozotocin. The control group consisted of 15 rats with normoglycemia. Sixty bilayered CM disks were labeled before implantation with aminohexanoyl-biotin-N-hydroxy-succinimide ester, of which 30 were immersed in 50 mg/mL TCN solution (experimental) or phosphate-buffered saline (PBS) (control). In each animal, two disks (control and experimental) were implanted in two midsagittal calvarial defects in the parietal bone. Similar non-implanted disks served as baseline. After 3 weeks, animals were euthanized, and the calvaria and overlying soft tissues were processed for demineralized histologic analysis. Horseradish peroxidase-conjugated streptavidin was used to detect the biotinylated collagen. The area of residual collagen within the membrane disks was measured and analyzed with a digital image analysis system. Several slides from each specimen were also stained with hematoxylin and eosin. Statistical analysis consisted of paired and unpaired t tests.


RESULTS
The amount of residual collagen in PBS-immersed disks was lower in rats with diabetes compared to rats with normoglycemia (69% of baseline versus 93%, respectively, P <0.001). TCN immersion increased the amount of residual collagen contents in both diabetic (83% of baseline) and healthy (97.5% of baseline) animals (P <0.0001).


CONCLUSIONS
Diabetes increases CM degradation, whereas immersion in 50 mg/mL TCN solution before implantation presents an opposite effect.
Department of Oral Biology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
Meizi
M
Eliezer
Carlos
C
Nemcovsky
George
G
Romanos
Avital
A
Kozlovsky
Haim
H
Tal
Roni
R
Kolerman
Miron
M
Weinreb
Ofer
O
Moses
D000818:Animals; D024141:Collagen Type IV / Q000187:drug effects* / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D006442:Glycated Hemoglobin / Q000032:analysis; D008297:Male; D008566:Membranes / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013752:Tetracycline / Q000494:pharmacology*
D024141:Collagen Type IV; D006442:Glycated Hemoglobin; D011500:Protein Synthesis Inhibitors; D013752:Tetracycline