Histochemical localisation of carboxylesterase activity in XXXX and @entity19 oral cavity mucosa.

@entity4832 @entity14705 @entity36434 @entity5 @entity6681 @entity19 @entity8908 @entity8038 @entity406 @entity2144 @entity8704 @entity35 @entity1543 @entity1098 @entity3094
@entity6681 (VA) is widely used within the chemical industry, in the manufacture of @entity4832 , and as @entity8908 emulsions in @entity2144 , adhesives, paper and paper @entity8038 . Chronic oral exposure of rodents to high concentrations of VA induces @entity5 within the oral cavity. Carboxylesterase-dependent hydrolysis of VA is thought to be critical in the development of @entity5 following inhalation exposure of animals to VA. Therefore, carboxylesterase activity was determined histochemically in the oral cavities of male F344 @entity35 and BDF @entity19 in order to explore the potential role of carboxylesterase-dependent hydrolysis of VA in the development of @entity5 . Following fixation in 10% neutral buffered @entity406 heads were decalcified in neutral saturated @entity1098 , embedded in resin, sectioned at six levels (three each for the upper and lower jaws), and carboxylesterase activity revealed in the tissue using @entity36434 as substrate. The localisation of carboxylesterase activity in freshly dissected @entity35 oral tissue was compared to that of the resin sections and found to be identical, thus validating the @entity8704 process. A similar pattern of carboxylesterase activity was observed for the two species. Staining was low in areas surrounding the teeth, and medium/high in the @entity14705 and those regions of the lower jaw not proximal to the teeth. In general the intensity of staining was greater in sections from the @entity35 compared to those from the @entity19 . By comparison, carboxylesterase activity was considerably higher in @entity19 nasal olfactory epithelium than in any of the oral tissues. Thus the mucosa of the oral cavity has the potential to hydrolyse VA to its metabolites, @entity1543 and @entity3094 , and the presence of carboxylesterases at this site is consistent with, and may be an important determining factor in, the development of oral @entity5 following exposure to VA.
