Keratinization of the esophageal epithelium of domesticated mammals.
We studied the esophageal epithelium for keratinization characteristics from samples of domesticated mammals of three nutrition groups (herbivores: horse, cattle, sheep; omnivores: pig, dog, rat; carnivores: cat) using histochemistry (keratins, disulfides), sulfur measurements, and cryo-SEM. Keratins were found in all esophageal layers of all species, except for the equine Stratum corneum. The positive reaction staining of Pan-keratin was remarkable, but decreased in intensity toward the outer layers, whereas in the pig and cat, staining was confined to the corneal layer. The herbivores revealed positive staining reactions in the upper Stratum spinosum, particularly in the sheep. Regarding single keratins, CK6 immunostating was found in most esophageal layers, but only weakly or negatively in the porcine and equine Stratum corneum. CK13 staining was restricted to the sheep and here was found in all layers. CK14 could be detected in the equine and feline Stratum basale, and upper vital layers of the dog and rat. CK17 appeared only in the Stratum spinosum and Stratum granulosum, but in all layers of the dog and cat. Disulfides reacted strongest in the Stratum corneum of the herbivores, as corroborated by the sulfur concentrations in the esophagus. Our study emphasized that keratins are very important for the mechanical stability of the epithelial cells and cell layers of the mammalian esophagus. The role of these keratins in the esophageal epithelia is of specific interest owing to the varying feed qualities and mechanical loads of different nutrition groups, which have to be countered.
Institute for Anatomy, University of Veterinary Medicine Hannover Foundation, Bischofsholer Damm 15, 30173 Hannover, Germany. Electronic address: wilfried.meyer@tiho-hannover.de.
Wilfried
W
Meyer
Institute for Anatomy, University of Veterinary Medicine Hannover Foundation, Bischofsholer Damm 15, 30173 Hannover, Germany.
Britta
B
Schoennagel
Institute of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
Johannes
J
Kacza
Institute for Physiological Chemistry, University of Veterinary Medicine Hannover Foundation, Hannover, Germany.
Roger
R
Busche
Institute for Anatomy, University of Veterinary Medicine Hannover Foundation, Bischofsholer Damm 15, 30173 Hannover, Germany.
Isabelle Nina
IN
Hornickel
Institute for Pathology, University of Veterinary Medicine Hannover Foundation, Hannover, Germany.
Marion
M
Hewicker-Trautwein
Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.
Anke
A
Schnapper
D000818:Animals; D000829:Animals, Domestic / Q000033:anatomy & histology / Q000378:metabolism; D002415:Cats; D002417:Cattle; D004285:Dogs; D004848:Epithelium / Q000378:metabolism / Q000382:microbiology / Q000648:ultrastructure; D004947:Esophagus / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006736:Horses / Q000033:anatomy & histology / Q000378:metabolism; D007633:Keratins / Q000378:metabolism*; D008297:Male; D009092:Mucous Membrane / Q000378:metabolism / Q000382:microbiology / Q000648:ultrastructure; D011916:Rats, Inbred F344; D034561:Sheep, Domestic / Q000033:anatomy & histology / Q000378:metabolism; D034421:Sus scrofa / Q000033:anatomy & histology / Q000378:metabolism
D007633:Keratins
Domesticated mammals; Epithelium; Esophagus; Histochemistry; Keratinization; Sulfur contents