Parathyroid ultrastructure after aldehyde fixation, high-pressure freezing, or microwave irradiation
Parathyroid cell variants, commonly observed in parathyroid glands fixed by immersion in glutaraldehyde, are believed to be the result of cyclic changes in the course of parathyroid hormone secretion. Immersion of bovine parathyroid glands in a mixture consisting of 1% glutaraldehyde, 1.5% formaldehyde, and 2.5% acrolein, followed by post-fixation in 1% osmium tetroxide, resulted in high uniformity with only one cell variant, whereas the same fixation procedure led to disruption of cell membranes and formation of cell variants in rat parathyroids. Parathyroid glands of both cattle and rats prepared by high-pressure quick-freezing and subsequent freeze-substitution contained only one cell variant. Excellent preservation of the ultrastructure of bovine and rat parathyroids, also exhibiting only one cell variant, was achieved by microwave irradiation in the presence of 2.5% glutaraldehyde in Na-cacodylate followed by post-fixation with OsO4 in Na-cacodylate or s-collidine, both containing Ca2+ and Mg2+. Use of the appropriate buffer, as well as osmication, is essential for successful fixation utilizing microwave energy. The main effects are considered to be heating specimens within sufficient short periods and enhancement of subsequent osmium fixation. The results support the idea, arising after examination of perfusion-fixed parathyroid tissue, that parathyroid cell variants occur during improper aldehyde fixation rather than that they express functional diversity.
- Research Organization:
- Univ. of Zuerich, Switzerland
- OSTI ID:
- 5516464
- Journal Information:
- J. Histochem. Cytochem.; (United States), Journal Name: J. Histochem. Cytochem.; (United States) Vol. 35:12; ISSN JHCYA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALDEHYDES
ANIMALS
BIOLOGICAL EFFECTS
BODY
CATTLE
CYTOLOGICAL TECHNIQUES
DOMESTIC ANIMALS
ELECTROMAGNETIC RADIATION
ENDOCRINE GLANDS
FREEZING
GLANDS
HORMONES
MAMMALS
MICROWAVE RADIATION
MORPHOLOGICAL CHANGES
ORGANIC COMPOUNDS
ORGANS
PARATHYROID GLANDS
RADIATIONS
RATS
RODENTS
RUMINANTS
ULTRASTRUCTURAL CHANGES
VERTEBRATES