The histological and histochemical features of the esophagus in local breed dogs (Canis familiaris)

Abstract

A total of eight samples of the esophagus of local breed dogs are used to investigate the histochemical features of the esophagus. The specimens are processed according to paraffin embedding technique protocols and the tissue sections are stained with hematoxylin and eosin, and masons trichrome combined with Alcian blue (pH2.5)-PAS. The esophagus folds the mucosa which is covered by keratinized to non-keratinized stratified squamous epithelium which contains numerous excretory common ducts of esophageal glands. The epithelial thickness of cervical, thoracic and abdominal parts of the esophagus are 221.95±3.41µm, 212.46±5.38 µm, and 173.15±4.09 µm respectively. The lamina propria of the cervical part of the esophagus lacks the muscularis mucosa, while the muscular mucosa in the thoracic part of the smooth muscles appears as scattered interrupted bundles. The esophageal glands are a type of compound tubular mucoserous constructed of the predominated mucous alveoli and little serous acini. When combined with Alcian blue (pH2.5)-PAS stain, the esophageal glands show strong acidic mucopolysaccharides within the mucous alveoli and light blue color within serous acini that denote weak acidic zymogen granules. Tunica muscularis is striated muscle fibers in cervical and thoracic parts and smooth in the abdominal part of the esophagus. The measured thickness of tunica muscularis of cervical, thoracic and abdominal parts are 568.76±6.90 µm, 703.29±7.54µm, and 338.98±7.26 µm respectively.