Imbalance of oxidative/anti-oxidative status induced by periodontitis is involved in apoptosis of rat submandibular glands.
OBJECTIVE
Epidemiologic studies suggest a relationship between periodontitis and salivary gland dysfunction. A rat periodontitis model was used to investigate whether a causal relationship exists between periodontitis and pathological changes of submandibular glands.


METHODS
Fourteen male Wistar rats (8 weeks old) were divided into two groups (n=7/group): a control group and periodontitis group. Periodontitis was induced by ligature placement around the mandibular first molars. Serum levels for reactive oxygen metabolites, anti-oxidant and tumour necrosis factor (TNF)-alpha were measured at baseline, 2 and 4 weeks. At 4 weeks, the levels of 8-hydroxydeoxyguanosine were determined to evaluate oxidative damage of submandibular glands. Expression of TNF-alpha mRNA and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) as well as histological findings were also evaluated in the submandibular glands.


RESULTS
The rats with experimental periodontitis showed increase in the levels of serum reactive oxygen metabolites and TNF-alpha, and a decrease of anti-oxidant power in a time-dependent manner. At 4 weeks, these rats also had significantly increased levels of 8-hydroxydeoxyguanosine and TNF-alpha, and increased number of TUNEL-positive cells and vacuolisation in the submandibular glands compared to the control rats.


CONCLUSIONS
Imbalance of circulating oxidative/anti-oxidative status may be involved in vacuolisation and apoptosis of submandibular glands in the rat periodontitis model.
Ekuni
Daisuke
D
Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
Endo
Yasumasa
Y
Irie
Koichiro
K
Azuma
Tetsuji
T
Tamaki
Naofumi
N
Tomofuji
Takaaki
T
Morita
Manabu
M
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D008026:Ligation; D008297:Male; D018384:Oxidative Stress; D010518:Periodontitis / Q000378:metabolism* / Q000473:pathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D013363:Submandibular Gland / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D000975:Antioxidants; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine