Holocrine secretory mechanism in granular ducts in Brown Norway rat. Histological study

Abstract

Mandibular glands in rodents contain a particular type of ducts, namely granular ducts. The cells lining these ducts present granules in their cytoplasm and secrete different substances. Our study aimed to assess these granules and the secretory mechanisms of these cells. The biological material was represented by 5 adult males Brown Wistar rats. We harvested the mandibular glands and processed them for histological examination. The slides showed that the cells lining the granular ducts present granules of different sizes with a spherical shape. They can occupy up to half of the cell cytoplasm and sometimes even more, forming large aggregates. The secretion of these large aggregates takes place through a holocrine secretory mechanism. The cells presenting this type of mechanism can be easily identified on the slides because they show discontinuity of the apical pole and a tendency of dispersion of the cellular contents. The other two types of secretory mechanisms are also present. In other words, the cells lining the granular ducts from Brown Norway rats mandibular glands, present merocrine, apocrine and holocrine secretory mechanisms. This is the first evidence of the holocrine mechanism cells from granular ducts in mandibular gland in this species.