Morphometric characterization of sexual differences in the rat sublingual gland

The effects of eugenol on histological, enzymatic, and oxidative parameters in the major salivary glands and pancreas of healthy male Wistar rats

OBJECTIVE

We evaluated the effects of eugenol on histological, enzymatic, and oxidative parameters in the pancreas, parotid, submandibular, and sublingual glands of healthy male rats.

DESIGN

Twenty-four adult Wistar rats were assigned into four groups (n = 6/group). Control rats received 2% Tween-20 (eugenol vehicle), whereas the other animals received 10, 20, and 40 mg kg-1 eugenol through gavage daily for 60 d. Major salivary and pancreatic glands were weighed and preserved fixed for microscopic analysis and frozen for in vitro assays.

RESULTS

Eugenol did not alter glands' weight and serum amylase activity regardless of the concentration. The highest dose of eugenol caused an increase in pancreatic amylase activity and a reduction of lipase activity from serum and pancreas. Eugenol at 40 mg kg-1 diminished the activity of SOD and FRAP in the submandibular gland and CAT and FRAP in the sublingual gland. However, it did not exert any effect on GST regardless of the gland. Additionally, 40 mg kg-1 eugenol increased MDA levels in pancreatic, parotid, and submandibular glands and NO levels in the sublingual. The concentrations of eugenol induced distinct responses in the glands regarding the activity of Na+/K+, Mg2+, and total ATPase activity. They also affected histomorphometrical and histochemistrical parameters in the submandibular gland only.

CONCLUSIONS

Results indicated that 40 mg kg-1 eugenol altered most of the biochemical and oxidatived parameters of digestive glands. Only submandibular glands presented histological changes after eugenol exposure suggesting potential implications for its function.

Histopathological comparison of the salivary glands’ acini and striated ducts after experimental prolonged daily administration of oral ubiquinone doses in rats

Also called coenzyme Q10 (CoQ10), Ubiquinone is a vitamin-like endogenously produced factor essential for Adenosine triphosphate (ATP) mitochondrial production. Several research studies have reported that the exogenous supplementation of CoQ10 can lead to excessive salivation, especially in patients complaining of dry mouth. The objective of this study was to investigate the effect of long-term daily use of CoQ10 on the salivary glands in experimental animals by comparing the diameters of the glandular acini and striated ducts of a CoQ10-treated group and a control group. Twenty-five white albino rats were randomly divided into two groups; the control group consisted of 10 rats, while the CoQ10-treated group comprised 15 rats. The latter received daily oral treatment of 300 mg/kg CoQ10 for six weeks. Samples of the parotid, submandibular and sublingual glands were then dissected and examined histologically for comparative measurement of the diameters of the glands’ acini and striated ducts. The CoQ10 treated group had mean diameters of the serous acini for the parotid (79.8±11.2 μm) and submandibular (81.07±13.5 μm) glands that were significantly higher (P<0.05) than their diameters in the control group (67.5±8.4 μm and 73.3±13.8 μm), respectively. However, the difference was not statistically significant when comparing the diameters of striated ducts of the CoQ10-treated group and the control group. Continuous and prolonged exposure to exogenous ubiquinone may cause hypertrophic dilation of the acini within the salivary glands, namely the parotid and submandibular glands, which might be the underlying mechanism for excessive salivation. This can be considered a reversible adaptive response.

Comprehensive histochemical and stereological study of the parotid and sublingual salivary glands in Caucasian squirrel (Sciurus anomalus)

The present investigation tries to reflect histochemical and stereological properties of the parotid gland (PG) and sublingual gland (SLG) in the Caucasian squirrel. Totally, five male Caucasian squirrels were used. The glands were examind histochemical using PAS, Alcian blue (AB, pH = 2.5) and Aldehyde fucshin (AF) stainings. Total volume of the glands, acini, ducts as well as total length of ducts were estimated using streological procedures. The PG had a unique morphology and were connected to each other with an intermediated isthmus. The SLG was oval-shaped. Serous acini of PG exhibited strong, negative and weak reaction with AF, AB and PAS, respectively. While, mucous acini of SLG showed positive staining for AB and PAS, and negative staining for AF. The ductal system was consisted of intercalated (Id), striated (SD) and excretory ducts (Ed). The Sd in PG was lined with simple cuboidal to the columnar epithelium, while it was lined with simple cuboidal epithelium in SLG. The Ed was lined with stratified cuboidal epithelium in both glands. The striated duct was longest duct in both glands, the excretory and intercalated ducts were the shortest ones in PG and SLG, respectively. The maximum total volume in both gland were blonged to the acini and straited ducts. It concluded that PG and SLG in the Caucasian squirrel have some distinct structural properties in comparison to other rodents and mammalis species.