Re: Sleep Apnea . . could it be low Glutathione?

[Guest guest]

Hi, Matt.

Yes, they do. But their CO2 production rate is low compared to the

total capacity of the lungs to exchange CO2 from the blood to the

air to be exhaled. The major contribution that the skeletal muscles

would normally make to the total CO2 production rate is not being

made in these PWCs. To cut down the lung's rate of removal of CO2

from the blood to a level where the blood CO2 concentration and

partial pressure will be in the normal control range, the

respiratory center concomitantly has to cut down the rate of oxygen

intake to a level below the low oxygen alarm threshold. That's

because the lungs both bring in oxygen and take out CO2. You can't

change one without changing the other. Normally there is enough

leeway in the CO2 level in the blood before the oxygen level in the

blood gets too low, so the respiratory center can control on the CO2

level and the oxygen level will automatically be sufficient so that

the cells that need oxygen can get enough from the blood. However,

in the group of PWCs who have this type of apnea, this is not the

case. In order to try to compensate for the muscles not producing

enough CO2, the respiratory center ends up lowering the oxygen level

to a point where the cells that " want " it, can't get enough. It's a

result of the mismatch in metabolic rates between the muscle cells

and the cells of the vital organs.

The diffusion of carbon dioxide from the blood to the air in the

alveoli of the lung is more rapid than the diffusion of oxygen in

the other direction, for the same difference in partial pressures of

these gases between the blood and the air in the alveoli. There is

an inherent difference in the diffusivity of these two gases through

the alveolar and capillary membranes. It's basically a Fick's first

law problem. In the normal operating range of the system, this

difference doesn't matter, because the partial pressure of oxygen in

normal atmospheric air is around 21% of total atmospheric pressure,

while for CO2 it is only about 0.03%, but when the respiratory

center is cutting down the breathing rate and depth in order to

raise the CO2 level in the blood without decreasing the O2 level too

much, this difference works against it.

Rich

> >

> > Hi, Matt.

> >

> > The oxygen level in the blood drops because the respiratory

center

> > slows and shallows the breathing. Thus, oxygen is not drawn

into

> > the lungs as fast as normal, and it is therefore not put into

the

> > blood as fast as normal. Since other organs are still using

> oxygen

> > at near normal rates, the oxygen level in the blood drops.

>

>

> ******And don't these organs likewise produce near normal rates of

> CO2?

>

>

>

> >

> > Thus, in an effort to raise the carbon dioxide level in the

blood,

> > the respiratory center lowers the oxygen level until it hits the

> > alarm level.

> >

> > Rich

>

>

>

> *******I wasn't asking why O2 drops. I asked why you think that

O2

> drops faster than CO2 rises--so much so that for select PWCs it is

> low O2 that has to trigger breathing, not elevated CO2.

>

>

> Matt

>

[Guest guest]

Hi, .

I looked into the operation of the respiratory center, and the

carbon dioxide partial pressure in the blood is the more important

factor in controlling the respiration. The reason is that hydrogen

ions do not cross the blood-brain barrier readily. Once the carbon

dioxide reaches the respiratory center, though, it causes the

formation of hydrogen ions by reacting with water to form carbonic

acid and then ionizing to form hydrogen ions and bicarbonate ions.

The respiratory center actually senses these hydrogen ions, but they

are produced secondarily in this way, and are not those that are

found in the blood flowing to the brain (realizing of course, that

they are in dynamic equilibrium, so that the actual individual ions

are constantly ionizing and associating, and it's the average

concentration of them over time that gives the pH).

I guess we don't know what your blood carbon dioxide partial

pressure is or was, so we can't reach a conclusion about whether

this model fits your case or not.

Rich

> >

> > Hi Rich,

> >

> > Does this all then imply that those with this problem (metabolic

> sleep

> > disorder) would have alkaline pH due to low carbon dioxide ? I

ask

> b/c

> > I have this and my blood pH is not alkaline, if anything, it is

a bit

> > too acidic. Is the low carbon dioxide the main factor or the pH ?

> >

> >

> >

> >

>

>

>

>

>

>

[Guest guest]

Hi, .

That's a good question. I haven't been able to find any information

about the O2 and CO2 levels in the blood when someone has a patent

foramen ovale, but it would certainly seem as though they would be

affected. As I understand it, depending on the case, the flow can be

either from the left atrium to the right atrium, or vice versa. In the

first case, some blood is returned to the lungs before it has passed

through the body, and in the second case, some blood is returned to

the peripheral circulation without passing through the lungs to pick

up oxygen. I think the first case would involved lowered cardiac

output, and though the oxygen level might be normal in the arterial

blood, I think it would be low in the venous blood, and the CO2 level

would be higher than normal there. In the second case, I would think

that the oxygen level in the peripheral blood would be lower than

normal, and the carbon dioxide level higher than normal. But as I

say, my standard medical books don't mention these levels.

The respiratory center in the brain does not directly measure the

oxygen level in the blood. It measures the carbon dioxide level, and

controls the breathing based on that. Oxygen level is measured by

chemoreceptors in the carotid arteries and in the aorta. It isn't

known how these chemoreptors measure the oxygen level.

In your last statement, I think you are referring to factors that

affect the binding of oxygen to hemoglobin. These include the pH and

the concentration of 2,3 BPG. If a person hyperventilates, the CO2

level in the blood goes down, and this makes the blood more alkaline

(higher pH). The Bohr effect then causes the oxygen to be more tightly

bound to the hemoglobin and not as easily released to tissues. The

same is true if the level of 2,3 BPG is too low for some reason.

One other interesting thing is that in hyperventilation the low carbon

dioxide has a direct effect in constricting the cerebral arteries.

This is why a person who hyperventilates becomes lightheaded and dizzy

and has parasthesias. I wonder if the same thing might be going on in

CFS, if the CO2 level gets too low because of the low production of

CO2 by the muscle cells and the respiratory center isn't able to raise

it enough.

Rich

>

> Vis-a-vis the relative levels of O2 and CO2 in the blood, would this

> not also be affected by the perforated foramena ovales (PFOs)

posited

> by Dr. Cheney - where, if I understand, correctly, some of the blood

> goes back out to the lungs before ever being circulated through the

> body? Also, I'm not clear how the brain monitors the O2 - it appears

> in some cases that oxygen is freely available in the blood but does

> not dissociate into the tissues, thus resulting in low CO2

production

> but continuing ample O2 in the blood and a deficit of O2 reaching

the tissues.

>