The Sun Drenched Elastic Band
"From 0 to 80 in a blink of an eye!” Yes that is how life
progresses. The leaves form and fall, the flowers bloom and wither and the
spring is replaced by winter. The discontent of the cold and biting weather
is the common refrain that echoes and echoes.
From the soft, moist elasticity of the newborn skin to the
weathered, dry, fragile paper machete of the aged, lurks the rub of time. What
happens is a slow but progressive march.
From the fantasy of a future to the hope of accomplishments
to the mindset of invulnerability resides the essence of youth. Here all systems are
on full alert, all mechanisms are a go and all actions are unpredictable.
Somewhere in that beautiful garden of blossoms and birth lies the propagation
of the species. There is the elastic band that stretches and fires and the pebble of procreation hits the
mark.
But what happens with age?
Even though the whole play of life will take many a scene and act,
let us use some latitude of brevity to consider it.
If you are young, you wont know or for that purpose want to know, what this is all about, just
yet. But if you are older this will fit perfectly in that drawer where you keep
all your passports hidden. The same passports that have seen the image of you
perceptibly morph from the smiling, wide-eyed, wonder-struck youth to the
frowning, eyelids at half-mast, loss of enthusiasm elderly. It is not what has
happened but rather, why it happened?
From the inner workings of thought, to the whips and scorns
of time, to the slings and arrows of physical abuse that have encompassed the human
body, this is a story of the underpinnings of the basic mechanisms of life. I
will leave the “thought” and “enthusiasm” issues for another time. This will be
about some of the changes in the inner circuitry that underlie our being.
The Cell and its Interior
Cells are the basic component of the human body. There are
trillions of them that form the surface of the skin and the various organs
within. Each cell is endowed with thousands, if not millions, of bits of
functioning material within that interact with each other and outside of the
cell’s domain to continue the process of existence.
Mitochondrium:
One of those pieces inside the cell is called the
mitochondrium, an exquisite piece of machinery that governs and creates energy
from the foods that we eat and distributes it along the rest of the cell for
creation of the various hormones such as Insulin, Thyroid stimulating hormone
etc, chemicals as in acetylcholine, epinephrine etc, neurotransmitters in the
brain cells for electrical transmission of neural impulses (that which make the
muscles twitch, the eyes to see, the eyelids to blink, the heart to beat, the
liver to metabolize etc). All that is accomplished through creation and
liberation of energy.
The mitochondrium is a actually a cyanobacterium that was
incorporated into the unicellular organisms some 1.5*10^9 years ago as a
self-sufficient, independent, energy-producing unit. It was the merger of
plant-life and animal-life to achieve a self-contained unit. Due to it’s “Eve”
derived unmodified DNA, we are able to trace the human species evolution from
the oldest (African) to the newest (South American) based on the mitochondrial
DNA.
As we age, the mitochondrial function becomes “leaky,” for
lack of better word, and in doing so, there is nascent oxygen created in the
process of making energy, that is normally slurped up by an enzyme called SOD
(Superoxide Desmutase), which accumulates. As more and more nascent oxygen (Oxygen
radical or “free radical”) is not gathered up, it begins to cause damage. The
radical oxygen is O of the O2. It has an extra electron hanging out that
latches onto any other weak bond within the cell. Those weak bonds exist in the
nucleus of the cells in the form of DNA.
The DNA as is well known, is comprised of four nucleic acids, Adenine,
Thymine, Guanine and Cytosine. They have complimentary linkage with one
another. Adenine always links to Thymine and Guanine to Cytosine, or AT,
CG. Since each strand of the
double helix carries a nucleic acid, the other carries the complimentary one.
These bonds that unite the four to each other are extremely tenuous hydroxyl
groups, and easily broken. Imagine if a stray electron comes charging, it will
easily disrupt one of those hydroxyl groups and the break might change the
nucleic acid itself, thus changing the three nucleic acid code (codon) and that
single nucleotide substitution may change the entire composition of the
operating gene. SNPs (Single Nucleotide Polymorphisms) as they are called, are a well known entity
detected through a mechanism called polymerase chain reaction or PCR, whereby the
aberrant DNA portion of the target diseased cell is amplified many-fold for
study. This subtle change can convert a “pro” to an “anti” and a “helper” might
turn into a “suppressor” and all the while we go from “May I…?” to “Can I…?” to
“Am I...?” indicating a slow but
progressive loss of function.
True, that both young and old fare the same way in regards
to these hits, the free-radicals, the sun rays, the UV light, X-Rays, and all
the rest of the daily bombardment that constitute around 10,000 hits daily on
our DNA.
"A thousand natural shocks that the flesh is heir to." Shakespeare.
In the young however, the robustness of the Mis-Match Repair
mechanisms within the cell (that get rid of deranged DNA) protect very well, but as one ages and takes the
hits, eventually overwhelming the repair mechanism, ultimately the cellular
function does go awry. This then creates the mischief that wreaks havoc. It
creates disease, like cancer and other chronic ailments.
For more reading on Genetics please read:
Telomeres:
Another mechanism involved is more akin to a Mission
Impossible self-destruct mechanism that makes everything go up in smoke. These
entities are called Telomeres. At the end of each chromosome there is a tail
that wags the entire dog so to speak. And it is not the tiny vestigial coccyx
of the human tail either, this one is potent in its absence. These telomeres
are identified as “Caps” on each end of the chromosome.
Telomere is a series of
nucleic acids in the form of TTAGGG present in the form of tandem repeats.
These repeats are 3-20 kilobases long and have a100-300 kb overall length.
Their function is to prevent overall chromosomal integrity by not allowing
fusion between one another and also to safeguard against gene degradation
within the chromosome. These Telomeres were discovered as a follow up discovery
to the cellular Hayflick limit, which states that a cell placed in a culture
medium will divide for a finite number of times and then die. Telomeres were
actually discovered in 1978 by Elizabeth Blackburn and Joseph Gall and confirm
the causal basis of the Hayflick Limit.
In their discovery, was the inherent map of the gradual
shortening of the telomeres with each division of the cell -chop off a piece of
the Telomere tail at each cellular division, this then confirmed the Leonard
Hayflick’s finding and gave credence to the predefined demise of the organism.
The loss of telomere chain leads to chromosomal anomalies, such as fusion and
subsequent degradation of the genes contained within the chromosomes leading to the disharmony of aging of the cells (loss of pliability, loss of function, loss of
growth) and also the resulting uncontrolled disruptive influence
from these signals that culminate in cancer.
It makes perfect sense when one considers the rate of breast
cancer in the young vs. the old and the disruptive function of age. At 20 years the risk
of cancer is calculated at 1 in 22,000 and graduating to the age of 80, the risk
increases to 1 in 5.
Telomerase:
There is an enzyme that can continue the constant elongation
of the telomeric tail, called the Telomerase.
This enzyme, replicates the
Telomere chain and is found in the constantly dividing and replenishing germ
cells and skin cells. Both organs lose the ability to continue fostering this
enzyme as evidenced by the loss of sperm or ova production with age and the dry
crackling, abrasion-ready, paper-thin pock-marked with various small and large
benign and malignant growths, skin of the aged. The cancer cell on the other
hand being devious in its wayward behavior co-opts the ability to create
Telomerase enzyme by gerrymandering the gene-regulating abilities so that it can
continue its endless replication ability.
The linear dimension of time follows birth to its death and
has a life-limiting script writ large in the scroll of human life. These are
the definable limits of human survival.
The elastic band is stretched and with the heat and temper of sun-drenched aging, it snaps!
This, the is our destiny!
Postponed possibly, Eventuality inevitable.
