Expression of two drug-metabolizing cytochrome P450-enzymes in human salivary glands.
OBJECTIVE
The oral cavity is constantly lubricated by saliva and even small amounts of xenobiotics and / or their metabolites in the saliva may affect the oral mucosa. Our aim was therefore to clarify if xenobiotic metabolizing enzymes CYP1A2 and CYP3A4 are expressed in salivary glands.


METHODS
Formalin-fixed paraffin-embedded specimens from parotid (10), submandibular (7) and labial (10) salivary glands were examined immunohistochemically and by in situ hybridization for expression of CYP1A2 and CYP3A4 protein and mRNA.


RESULTS
CYP1A2 and CYP3A4 protein and mRNA were detected in ductal and seromucous / serous acinar cells in all gland types although to a varying degree and intensity. Mucous acinar cells were positive to a lesser extent.


CONCLUSIONS
The results indicate a xenobiotic metabolizing capability of salivary glands. This may have implications for development of oral mucosal disease as a result of mucosal exposure to metabolites originating from internal sources (blood) as well as from saliva.
Kragelund
C
C
Department of Odontology, Division of Oral Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. ckr@odont.ku.dk
Hansen
C
C
Torpet
L A
LA
Nauntofte
B
B
Brøsen
K
K
Pedersen
A M L
AM
Buchwald
C
C
Therkildsen
M H
MH
Reibel
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000378:metabolism; D019388:Cytochrome P-450 CYP1A2 / Q000032:analysis*; D051544:Cytochrome P-450 CYP3A / Q000032:analysis*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000201:enzymology; D010306:Parotid Gland / Q000201:enzymology; D018987:Salivary Ducts / Q000201:enzymology; D012469:Salivary Glands / Q000201:enzymology*; D012470:Salivary Glands, Minor / Q000201:enzymology; D012471:Salivary Proteins and Peptides / Q000032:analysis*; D012704:Serous Membrane / Q000201:enzymology; D012907:Smoking / Q000378:metabolism; D013363:Submandibular Gland / Q000201:enzymology; D015262:Xenobiotics / Q000378:metabolism; D055815:Young Adult
D012471:Salivary Proteins and Peptides; D015262:Xenobiotics; C504573:CYP1A2 protein, human; D019388:Cytochrome P-450 CYP1A2; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human