Ultrastructural changes of the palatal mucosa following application of 4-nitroquinoline-l-oxide (4NQO) in rats subjected to major salivary gland excision.
OBJECTIVE
It has been suggested that saliva exerts a protective role against the carcinogenic effect of various substances in the oral cavity. The objective of this study was to examine the ultrastructural changes of the palatal mucosa caused by the application of 4-nitroquinoline-l-oxide (4NQO) in the presence or absence of saliva.


METHODS
Wistar-Furth rats subjected and not subjected to total bilateral excision of the major salivary glands were either painted with an aqueous solution of 4NQO or with propylene glycol only (controls). Two animals of each group were humanely killed periodically. The areas of the palatal lesions were immediately sliced and processed for TEM examination.


RESULTS
Ultrastructurally, the progressive changes to squamous cell carcinoma were observed in the animals painted with 4NQO. In the desalivated animals group, the ultrastructural alterations appeared earlier than in the group with salivary glands.


CONCLUSIONS
Saliva appeared to delay but not hinder tumor induction by 4NQO.
Department of Histology and Embryology, Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Antonia
A
Sioga
Louise
L
Economou
Eleftherios G
EG
Kaklamanos
Vasilios
V
Antoniades
George
G
Keramidas
Anastasios
A
Manthos
Kostantinos
K
Antoniades
D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D008297:Male; D046529:Microscopy, Electron, Transmission; D009061:Mouth Mucosa / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D010157:Palatal Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure*; D021362:Palate, Hard; D051381:Rats; D017208:Rats, Wistar; D012463:Saliva / Q000502:physiology*; D012469:Salivary Glands / Q000502:physiology* / Q000601:surgery
D002273:Carcinogens; D015112:4-Nitroquinoline-1-oxide