OBSTRUCTIVE SIALADENITIS - A RAT MODEL

Obstructive adenitis of major salivary glands is a common entity. Alth ough the pathologic features are well recognized, the various cell typ es involved in the atrophy and subsequent regeneration of the obstruct ed salivary gland have been controversial. For this reason, an animal model of obstructive sialadenitis that induced atrophy in the rat paro tid gland was developed. A clamp was devised that would occlude the ma in excretory duct of the gland inducing atrophy, but that, following r emoval, left the duct patent and allowed regeneration to occur. Both a trophy and regeneration were studied, and the results presented. The n umber and location of cycling acinar, intercalated, striated, and excr etory duct cells were identified, using an antibody to proliferating c ell nuclear antigen (PCNA). All cell types were induced to cycle durin g both the atrophy and regeneration phase, but the degree of cycling w as more pronounced during regeneration. Three days after release of th e duct obstruction, cycling acinar cells had increased 40-fold, while striated and intercalated ducts increased 6.5- and 5.0-fold, respectiv ely. More importantly, peak cycling of acinar cells preceded, but para lleled, the increase in acinar cell composition of the gland. This mod el of obstructive sialadenitis indicates that all cell types are respo nsible for regeneration in the obstructed rat parotid gland.