Study of the histological structure of esophagus in different regions in the sheep: effects of fixation time and alternate methods of staining

To evaluation effect of the various staining methods on histological structure of sheep esophagus in different times، five mature female sheep from Lori Bakhtiyari breed were selected from Shahrekrod abattoir. The animals were slaughtered and the whole esophagus separated and pieces of 5 mm thickness were cut in the proximal، middle and distal regions. The samples were immersed in fixative solution of 10% buffered formalin for 24، 48 and 168 hours and prepared tissue sections، were stained by Hematoxylin and eosin، Verhoeff-elastin and Cason''s Trichrome were measured thickness of the tissue layers of esophagus and were registered. Results showed that the epithelial thickness was significantly greater in all fixation times and three types staining in comparison with two other regions. The propria-submu thicknesses were significantly increased by increment time in three types staining. The type of staining and the time did not have any statistically significant effect on the muscular layer thickness.