OBJECTIVETo investigate luciferase gene expression and pathological changes of submandibular glands (SMG) of rats after adenovirus-mediated gene transfer.

METHODSAdenovirus-mediated luciferase gene (AdCMVLuc, 10(8) pfu in 50 microl) was injected in to SMG of forty wistar rats. The SMGs were harvested for gene expression measurement and pathological study after 3 days, 1,2,4 and 8 weeks.

RESULTSPeak expression was observed in three days following administration of the vector however, gene expression in submandibular glands decreased rapidly. the pathological changes induced by retrograde injection of AdCMVLuc included: after 3 days to one week, compression of acini, dilation of terminal ducts; after two weeks, slight atrophy of a part of acini, increase of iteracinar distance and focal lymphocyte infiltration in lobules and interlobular ducts; after 4 weeks, recovery evidence was found in acini; after 8 weeks, normal acini and ducts were found. The ultrastructural changes included: 3 days, much more rough endoplasmic reticulum was found both in acini and duct epithelial cell; a lot of mucus drops were found in acini; after 1 week, microvillus decreased in duct epithelial cells, mitochondria increased significantly in acini; intercellular space was enlarged.

CONCLUSIONSAdenovirus-mediated gene transfer can produce biological proteins and induce marked inflammatory changes in rat SMG. The ultrastructural changes suggest high protein synthesis activity in the acinar cells after gene transfer.