Lipids and cholesterol clefts in the lacunar cells of snake skin
Autor: | Morris K. Jackson, Mohamed Sharawy |
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Rok vydání: | 1978 |
Předmět: |
Pathology
medicine.medical_specialty Uranyl acetate Snakes Vacuole Lipid Metabolism Agricultural and Biological Sciences (miscellaneous) law.invention chemistry.chemical_compound medicine.anatomical_structure chemistry Osmium tetroxide law Vacuoles medicine Ultrastructure Microtome Animals Epidermis Sudan Black B Cholesterol Esters Anatomy Electron microscope Skin |
Zdroj: | The Anatomical record. 190(1) |
ISSN: | 0003-276X |
Popis: | The lacunar cell layer in rat snake epidermis contains many characteristic intracellular vacuoles. The lipid nature of these large round vacu- oles was demonstrated by histochemical and ultrastructural investigations. Rhomboid-shaped clefts, similar to cholesterol ester clefts. were observed in proximity to the vacuoles. The lacunar cell layer in snake skin was termed as such by Maderson ('65) because its cells contain numerous lacunae or vacuoles of various sizes within their cytoplasm. Al- though the lacunar cells are viable cells which gradually keratinize and contribute to the juxtaposed alpha keratin layer, the chemical and histochemical nature of their vacuoles is unknown; further, the contributions of the vacuoles in the process of keratinization is not understood. This communication reports on the lipid nature of the large vacuoles, and in addition, demonstrates the presence of pe- culiar cleft-like structures within the lacunar cells of the rat snake integument. METHODS AND MATERIALS Skin biopsies were taken from twelve heal- thy adult Texas rat snakes, Elaphe obsoleta lindheineri. Formalin fixed tissues were em- bedded in 2-butoxyethanol glycol meth- acrylate plastic, and 0.5- to 3.0-p-thick sec- tions were cut with a Sorvall JB-4A micro- tome. The plastic sections were mounted and stained with hematoxylin and eosin (H and E). Other formalin fixed tissues were infiltrated in ascending concentrations of gelatin and embedded in 25% gelatin. These blocks were frozen and sectioned at 20- to 50-p thickness with a freezing microtome. The sections were upgraded to 70% ethyl alcohol, stained with Sudan black B, and mounted on slides. For examination of cellular ultrastructure, tissues were fixed in 6.25% cacodylate buf- fered glutaraldyhyde, post-fixed in 2% osmium tetroxide, dehydrated rapidly through graded strengths of ethanol, and infiltrated and embedded in Araldite 502 (Ladd Research) or Epon 812 (Polysciences). Mounted ultrathin ANAT. REC. (1978) 190: 41-46. sections were stained with 2% uranyl acetate and 1% lead citrate and examined with an RCA EMU 4C electron microscope. RESULTS |
Databáze: | OpenAIRE |
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