Phenoptosis
From Wikipedia, the free encyclopedia
Phenoptosis (pheno - showing or displaying a type, ptosis - programmed death) signifies the programmed death of an organism, ie that its biology includes features that under certain circumstances will cause it to degenerate and die off. Phenoptosis is a common feature of living beings, whose ramifications for humans is still being explored.
A common route for phenoptosis is breakdown of glucocorticoid regulation and inhibition, leading to massive excess of these corticosteroids in the body. [1]
The process affects many species, from yeast to salmon.
[edit] More
Robert Sapolsky discusses phenoptosis in his book Why Zebras don't get Ulcers, 3rd Ed., p.245-247. He states that:
- "If you catch salmon right after they spawn... you find they have huge adrenal glands, peptic ulcers, and kidney lesions, their immune systems have collapsed... [and they] have stupendously high glucocortocoid concentrations in their bloodstreams. When salmon spawn, regulation of their glucocortocoid secretion breaks down... But is the glucocorticoid excess really responsible for their death? Yup. Take a salmon right after spawning, remove its adrenals, and it will live for a year afterward.
- "The bizarre thing is that this sequence... not only occurs in five species of salmon, but also among a dozen species of Australian marsupial mice... Pacific salmon and marsupial mice are not close relatives. At least twice in evolutionary history, completely independently, two very different sets of species have come up with the identical trick: if you want to degenerate very fast, secrete a ton of glucocorticoids."
[edit] See also
 |
This biology article is a stub. You can help Wikipedia by expanding it. |
