Morphological and functional changes of the rat parotid glandular cells by clipping and reopening the parotid duct, using HAM8 antibody

Abstract

The purpose of this experiment is to examine the proliferative process of rat acinar cells after parotid duct ligation and reopening. Two experimental groups were observed. The first group was killed from 0 to 14 days after the duct ligation. In the second group, the duct was clipped for 14 days, and it was reopened. Following a period of from 2 to 28 days after removal of the clip, the glands were removed to perform a histological analysis, including hematoxylin-eosin (HE), immunofluorescent staining using HAM8 antibody, which recognizes connexin 32, and transmission electron microscopy (TEM). In the experimental gland from the 1st group at 6 days after ligation (I-6D), the acinar cells disappeared. In the tissue from the 2nd group 8 days after reopening (II-8D), newly formed acinar cells were found again. Lobular structure of the parotid glands recovered in the II-21D. HAM8 signals were observed between normal acinar cells, while they declined in the tissue from I-1D, and they were not observed in the I-2D. HAM8 signals were first observed in the II-25D and then subsequently returned to normal levels in the II-28D. These results suggest that the intercellular communication and functional recovery was not complete 25 days after reopening of the duct.In conclusion, the recovery of the acinar structure was recognized during an extended period of duct ligation, however, a time lag between the morphological and functional recovery was found to exist.

Anatomy of parotid gland and its secretory ducts in sheep

“…In the literature, the mean length of the parotid gland of sheep was 6.04±0.48 cm and in goat 6.56±0.361 cm [18] and in dog 3.96±0.26 cm [11]. In our study, the average length of the parotid gland in sheep was identified as 5.87 ±1.04 cm (Table 1).…”

“…The mass of the mandibular and parotid gland was reported to be 9.0 g and 11.0 g, respectively, in sheep [14,22,24]. In another study the mass of mandibular and parotid gland in sheep was reported to be 16.2 ± 4.6 g and 13.5 ± 2.6 g [7].The mean length of the parotid gland of sheep 6.04±0.48 cm and goat 6.56±0.361 cm [18] and 3.96±0.26 cm in dog [11]. Human parotid glands average weight is 25-30 g [19] and 14-28 g [25].…”

“…The structure of salivary glands in mammals has been thoroughly studied histological, histochemical, sialografic method [7,10,11,18,24].…”

Duct ligation/de-ligation model: exploring mechanisms for salivary gland injury and regeneration

“…Furthermore, there was a significant decrease in the quantity of cholinergic and adrenergic receptors and a notable reduction in the secretory response to phenylephrine and isoproterenol. Subsequently, 14-day duct ligation has become the most frequently employed model for the research of salivary gland fibrosis ( Miyazaki, et al, 2008 ).…”