1. Ms. Eileen Rodriguez Seminar
We should know that the physiology, morphology and anatomy have an intimately
relationship between them and in that same way the neurology and the healthy functions of
the human body depend of each other. An example of the quote established previously is
the relationship that we found between the relaxation and contraction of the muscles and
sphincters of the Gastrointestinal (GI) tract with the production of Nitric Oxide. Nitric
Oxide (NO) is a very simple compound that is found like a gas in the human body and it
functions like a mediator of diverse functions of the organisms. These functions may
include: secondary intracellular messenger and intracellular messenger. These introductions
of this expositive essay have the objective to provide to the audience facts (that had been
learns by the author of this same essay) that are very important to understand the Seminar:
From the Gut to Graduate School provided by Ms. Eileen Rodriguez.
First we should know statistics about the GI problems that affect the population of
the United States of America: 41% of the population suffer of GI problems and of that
41%, 25% are caused by motility disorders like:
a. Diabetic Gastroparesis- a disease which cause that the stomach takes too
long to empty.
b. Achalasia- consists of the incapacity of fiber to relax
c. Dyspepsia- impaired of digestion
d. Chronic Constipation
e. Bowel Incontinence
f. Irritable Bowel Syndrome
g. Chaga’s Diseases- caused by a parasite
h. Hirshprung’s Disease
i. Infantile Hypertophic Stenosis
j. Gatroesophagic Reflux
Peristalsis, contractions that are like rhythmic wave that move the food along the GI,
is regulated by the nerve system that it’s found in the GI tissues of the organ’s walls
specifically in the myenteric plexus. The myenteric plexus is like a concentration of nerve
that may function like a nucleus for the productions of neurotransmitters. In this myenteric
plexus we found the NANC (Non Adrenergic and non-cholinergic inhibitory nerves that
functions with adrenaline) and the actuation of these nerves relax the smooth muscles along
the GI tract. There are four neurotransmitters that can mediate the action of inhibition and
they are:
a. Nitric Oxide
b. ATP
c. Carbon Monoxide
d. Vasoactive Intestinal peptide
The Nitric Oxide is the one that Ms Eileen Rodriguez chose because it was the more
suspect neurotransmitter agent that cause the peristalsis (relaxation of the muscle
specifically) On the other hand she expressed that ATP may also be a good one suspect but
previous studies have shown that Nitric Oxide have more relation with the peristalsis
reaction.
NO is synthesize by the Nitric Oxide Neuronal Synthetase in the myenteric plexus an
it is produce by demand of the GI tract (that may have reference to metabolic pathway
inhibitors and activators) This NO can’t be stored in the secretory vesicles. That is the

2. reason of why it has to be constantly produce. It’s important to mention that NO synthetase
is regulated by the R type Calcium Channels that are controlled by a specific type of
Calcium. With this information we can establish that Calcium is the activator and that
antagonist factor of NOS.
But the problem is that this information is inconclusive because we have to know
how the process is. To solve that problem Ms Eileen Rodriguez established the next
question for her research: Do activation of R type Calcium Channels lead to activation off
inhibitory nerves and relaxation of the intestines? Then she conceives this hypothesis:
Calcium Channel was activated, that activation initiates the NOS to produce NO and that
cause the relaxation of the muscle. After that she created a procedure that consist in the use
of 10 centimeters of the Guinea Pig intestine (that is functional for the experiment at least 6
hours) and put the intestine in a Pexiglas Organ Bath with Krebs Solution in a temperature
of 37 Celsius Grades and then measure the relaxation or contraction of the muscle with an
isometric force transducer. Also the researcher must apply the drugs to the solution. In this
case Eileen used the next drugs: histamine, Nickel Chloride and Nitrite L Argenine. The
results was that the histamine cause an increase of tension, the Nickel Chloride block the
R type Calcium Channels and for that reason the synthesis of NO and the Nitrite L
Argenine cause the inhibition of the NOS. We can conclude of this research that the
Calcium Channels are essential to the NO synthesis. If we don’t have Calcium Channels
working properly then we will have an instability in our peristalsis activity because the
absent of NO (that cause that the muscle contractile)
As an answer to that research results, Ms Eileen Rodriguez, that is candidate for a
PhD in the Michigan State University, did a research of: What is the effect of Nickel
Chloride, Nitrite L Argenine and Apamin on the contractile response of the intestine? The
results were that if use the three at the same time may cause a higher potassium levels in the
GI tract and will cause the muscle to contractile for a longer type. She said that in this way:
a. NiCl- cause a significant contractile act
b. NiCl+ Nitrite L Argenine- Cause a non significant change in
comparison wwith NiCl
c. NiCl+ Nitrite L Argenine+ Apamin- cause a significant
contractile activity
Some additional data that she provides was that: Sumatriptan is an activator of NO
neurons and that Amyl Nitrate is a donor of NO.
These researches were important because the scientist may use it to understand in a
better way all of this motility disorders and create better treatments. In 2007 the FDA shut
down the production of the antispasmodic call Tegasered because this medicine causes
several secondary reactions that affect the patients liver and kidneys.