Effect of alendronate on alveolar bone resorption and angiogenesis in rats with experimental periapical lesions.
OBJECTIVE
To investigate the effects of systemically administered alendronate, one of the most potent bisphosphonates (BPs), on alveolar bone resorption and angiogenesis in rats subjected to experimental periapical lesions over two time periods.


METHODS
Forty adult Sprague-Dawley (SD) rats were divided equally into control and experimental groups, and the pulp chambers of mandibular first molars of all rats were exposed to the oral environment to induce periapical lesions. The experimental group received daily subcutaneous injections of alendronate at a dose of 0.25 mg kg(-1), whereas the control group received only the saline vehicle. These injections were initiated 1 week before the periapical lesion induction and then continued daily throughout the entire experimental period. After 2 or 4 weeks following pulp exposure, the rats were killed, and the mandibles were examined histologically for periapical bone loss area, number of microvascular vessels (NMV) and tartrate-resistant acid phosphatase (TRAP) activity.


RESULTS
Overall, periapical bone loss area and the number of TRAP-positive cells (osteoclasts) were significantly decreased at 2 and 4 weeks, respectively, after daily subcutaneous injection of alendronate compared with the control group (P < 0.05). There was no significant decrease change in NMV (P > 0.05).


CONCLUSIONS
Administration of alendronate to rats might inhibit alveolar bone resorption associated with periapical disease, which might not lead to impairment of angiogenesis. However, because of the differences between rats and humans, one has to consider the possible consequences of this treatment in the clinic.
Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
H
H
Xiong
L
L
Wei
Y
Y
Hu
C
C
Zhang
B
B
Peng
D000135:Acid Phosphatase / Q000187:drug effects / Q000378:metabolism; D019386:Alendronate / Q000009:adverse effects*; D016301:Alveolar Bone Loss / Q000150:complications / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000539:Alveolar Process / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D000818:Animals; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D001862:Bone Resorption / Q000150:complications / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D007527:Isoenzymes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008334:Mandible / Q000187:drug effects / Q000473:pathology; D055806:Microvessels / Q000187:drug effects; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010483:Periapical Diseases / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D000071681:Tartrate-Resistant Acid Phosphatase
D050071:Bone Density Conservation Agents; D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D019386:Alendronate