Parathyroid oxyphil cells are one out of the two types of cells found in the parathyroid gland, the other being
parathyroid chief cell
Parathyroid chief cells (also called parathyroid principal cells or simply parathyroid cells, C-cells, or parafollicular cells) are one of the two cell types of the parathyroid glands, along with oxyphil cells. The chief cells are much more preva ...
. Oxyphil cells are only found in a select few number of species and humans are one of them.
These cells can be found in clusters in the center of the section and at the periphery. Oxyphil cells appear at the onset of puberty, but have no known function. It is perceived that oxyphil cells may be derived from chief cells at puberty, as they are not present at birth like chief cells. Oxyphil cells increase in number with age.
Structure
Oxyphil cells may be binucleated and proteins found within their cytoplasms are basic, resulting in acidophilic cytoplasms. Cytochemically, oxyphil cells and
C cells are fairly similar. Oxyphil cells are much larger in size (12–20 μm) compared with chief cells (6–8 μm) and also stain lighter than chief cells. Oxyphil cells have a cytoplasm filled with many, large mitochondria. Oxyphil cells have abundant cytoplasmic glycogen and ribosomes that are interspersed between the mitochondria. The endoplasmic reticulum, Golgi apparatuses, and secretory granules are poorly developed in oxyphil cells of normal parathyroid glands
Function
With
nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emitting ...
scans, they selectively take up the
Technetium
Technetium is a chemical element with the symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. All available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous ...
-
sestamibi
Technetium (99mTc) sestamibi (INN) (commonly sestamibi; USP: technetium Tc 99m sestamibi; trade name Cardiolite) is a pharmaceutical agent used in nuclear medicine imaging. The drug is a coordination complex consisting of the radioisotope techn ...
complex radiotracer to allow delineation of glandular anatomy.
Oxyphil cells have been shown to express parathyroid-relevant genes found in the chief cells and have the potential to produce additional autocrine/paracrine factors, such as
parathyroid hormone-related protein (PTHrP) and
calcitriol
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the ...
. Oxyphil cells have also been shown to have higher
oxidative
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
and
hydrolytic
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolysi ...
enzyme activity
Enzyme assays are laboratory methods for measuring enzymatic activity. They are vital for the study of enzyme kinetics and enzyme inhibition.
Enzyme units
The quantity or concentration of an enzyme can be expressed in molar amounts, as with a ...
than chief cells due to having more
mitochondria
A mitochondrion (; ) is an organelle found in the Cell (biology), cells of most Eukaryotes, such as animals, plants and Fungus, fungi. Mitochondria have a double lipid bilayer, membrane structure and use aerobic respiration to generate adenosi ...
.
Oxyphil cells have significantly more
calcium-sensing receptor
The calcium-sensing receptor (CaSR) is a Class C G-protein coupled receptor which senses extracellular levels of calcium ions. It is primarily expressed in the parathyroid gland, the renal tubules of the kidney and the brain. In the parathyroid ...
s (CaSRs) than chief cells.
More work needs to be done to fully understand the functions of these cells and their secretions.
See also
*
List of human cell types derived from the germ layers
This is a list of cells in humans derived from the three embryonic germ layers – ectoderm, mesoderm, and endoderm.
Cells derived from ectoderm
Surface ectoderm Skin
* Trichocyte
* Keratinocyte
Anterior pituitary
* Gonadotrope
* Corticotro ...
References
Endocrine cells
Human cells
Parathyroid
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