EPITHELIAL MUCOSUBSTANCES AND ARGYROPHIL CELLS IN BRENNER TUMOURS

Abstract Hypothermic and hypoxic environments create strong selective pressure on native species by affecting, among other things, the relationship between energy intake and allocation. In order to detect the adaptation of Phrynocephalus vlangalii to such energy limitation, the morphological structure and argyrophil cells of the digestive tract of 80 individuals from two different altitudes in the Qinghai-Tibet Plateau were compared using overall anatomy as well as paraffin sectioning of specific organs. Compared with the low-altitude population, the high-altitude individuals were found to have a significantly longer stomach and duodenum, longer and wider villus in the small intestine, larger surface area in duodenum and jejunum, and more argyrophilic cells in stomach and duodenum. Our results indicate that the morphological and histological change of the digestive tract may be conductive to the plateau adaptability of P. vlangalii by enhancing the efficiency of digestion and absorption. For a more general conclusion to be drawn, comparison of more populations at both altitudes is required in addition to verifying how phenotypically flexible these traits are.

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Functional morphology of the esophagus of the tropical house gecko Hemidactylus mabouia (Squamata: Gekkonidae)

Animal Biology ◽

10.1163/15707563-00002469 ◽

2015 ◽

Vol 65 (2) ◽

pp. 177-191

Author(s):

Sirlene Souza Rodrigues-Sartori ◽

Katiane de Oliveira Pinto Coelho Nogueira ◽

Vinícius Albano Araújo ◽

Clóvis Andrade Neves

Keyword(s):

Functional Morphology ◽

Food Habits ◽

Endocrine Cells ◽

Esophageal Mucosa ◽

Anterior Portion ◽

Argyrophil Cells ◽

Morphological Studies ◽

Ciliary Action ◽

Acid Mucins ◽

Hemidactylus Mabouia

In order to understand the biology of species that easily establish themselves in new environments, morphological studies are essential. This study aimed to describe the esophageal functional morphology ofHemidactylus mabouia, indicating adaptations to food habits. Seventeen adult specimens were used for anatomical, topological, histological, and histochemical analyses. Histological sections were stained with toluidine blue or submitted to techniques for identification of argyrophil and argentaffin endocrine cells, proteins, and glycoconjugates. The esophagus ofH. mabouiais a tubular straight-lined organ, and its anterior portion is dilated, facilitating the swallowing of whole prey. The esophageal epithelium is pseudostratified, containing cells secreting neutral and acid mucins. At the esophagogastric transition, we found a mixture of this epithelium with a simple prismatic epithelium secreting neutral mucins. The esophagus lamina propria is thin and non-glandular. At the esophagogastric transition it becomes thick and filled by branched simple acinous glands, with cells secreting neutral mucins, zymogenic cells, and argentaffin endocrine cells, with no argyrophil cells. The mucins protect the esophageal mucosa and lubricate the channel to facilitate the passage of food, while pepsinogen in the stomach increases the levels of pepsin for proteolytic digestion. The muscular tunica is made up of smooth muscle cells. Ciliary action, in addition to muscle contractions, facilitates the swallowing of small prey.

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