3 - Hemoglobin
Hemoglobin releases oxygen in exchange for carbon
dioxide and provides a prime example of a
mechanism that goes into action to protect centers of
high metabolic rate like the inferior colliculus.
Greater metabolism in the inferior colliculus
generates more carbon dioxide than in other brain
areas, thus forcing whatever amount of oxygen
carried by hemoglobin to be delivered to the inferior
colliculus first. Under hypoxic conditions, this can
leave insufficient oxygen available to less
metabolically active areas of the brain such as the
motor system of the cerebral cortex; thus the
association observed by Myers (1972) of cerebral
palsy with partial insufficiency of oxygen late in
gestation [1].
During an hypoxic episode hemoglobin provides
immediate adjustment that protects tissues of highest
metabolic rate, as described in the textbook of
biochemistry by White, Handler, and Smith (1968) [2]:
Hemoglobin releases oxygen in exchange for carbon
dioxide and provides a prime example of a
mechanism that goes into action to protect centers of
high metabolic rate like the inferior colliculus.
Greater metabolism in the inferior colliculus
generates more carbon dioxide than in other brain
areas, thus forcing whatever amount of oxygen
carried by hemoglobin to be delivered to the inferior
colliculus first. Under hypoxic conditions, this can
leave insufficient oxygen available to less
metabolically active areas of the brain such as the
motor system of the cerebral cortex; thus the
association observed by Myers (1972) of cerebral
palsy with partial insufficiency of oxygen late in
gestation [1].
During an hypoxic episode hemoglobin provides
immediate adjustment that protects tissues of highest
metabolic rate, as described in the textbook of
biochemistry by White, Handler, and Smith (1968) [2]:
"Primitive organisms rely on diffusion through
their environmental media to provide the
oxygen needed for their metabolism and to
remove the carbon dioxide produced.
The active metabolism of mammalian tissues
remote from the atmosphere is possible
because of a mechanism which provides
constant delivery of oxygen and removal of
carbon dioxide. The magnitude of this task
may be appreciated from the fact that a man
oxidizing 3000 Cal. Of mixed food per day
uses about 600 liters of oxygen (27 moles)
and produces about 480 liters of carbon
dioxide (22 moles).
Through the action of hemoglobin, oxygen is
abstracted from the air, carried within a few
seconds to the most distant parts of the
body, and delivered to the tissues at a
pressure only slightly less than that which it
existed in the atmosphere.
The CO2 produced daily by the tissues
becomes H2CO3, an acid, in an amount
equivalent to 2 liters of concentrated
hydrochloric acid; yet all this acid normally
pours from the tissues, through the blood,
and out of the lungs with a change in the pH
of blood of no more than few hundredths of a
pH unit. "
[2, p758 – Chapter 32. Chemistry of Respiration]
their environmental media to provide the
oxygen needed for their metabolism and to
remove the carbon dioxide produced.
The active metabolism of mammalian tissues
remote from the atmosphere is possible
because of a mechanism which provides
constant delivery of oxygen and removal of
carbon dioxide. The magnitude of this task
may be appreciated from the fact that a man
oxidizing 3000 Cal. Of mixed food per day
uses about 600 liters of oxygen (27 moles)
and produces about 480 liters of carbon
dioxide (22 moles).
Through the action of hemoglobin, oxygen is
abstracted from the air, carried within a few
seconds to the most distant parts of the
body, and delivered to the tissues at a
pressure only slightly less than that which it
existed in the atmosphere.
The CO2 produced daily by the tissues
becomes H2CO3, an acid, in an amount
equivalent to 2 liters of concentrated
hydrochloric acid; yet all this acid normally
pours from the tissues, through the blood,
and out of the lungs with a change in the pH
of blood of no more than few hundredths of a
pH unit. "
[2, p758 – Chapter 32. Chemistry of Respiration]
The delivery of oxygen by hemoglobin in exchange for
the metabolic end-product carbon dioxide is known as
the "Bohr Effect" [3]. Above is a picture of Christian
Bohr (1857-1911). He was the father of Nils Bohr,
who was awarded a Nobel Prize for determining the
electron-proton structure of hydrogen. Discovery of
the Bohr Effect of hemoglobin was certainly as great a
scientific achievement.
the metabolic end-product carbon dioxide is known as
the "Bohr Effect" [3]. Above is a picture of Christian
Bohr (1857-1911). He was the father of Nils Bohr,
who was awarded a Nobel Prize for determining the
electron-proton structure of hydrogen. Discovery of
the Bohr Effect of hemoglobin was certainly as great a
scientific achievement.
- Myers RE (1972) Two
patterns of perinatal brain
damage and their conditions
of occurrence. - White A, Handler P, Smith EL
(1968) Principles of
Biochemistry, fourth edition. - Jensen FB (2004) Red blood
cell pH, the Bohr effect, and
other oxygenation-linked
phenomena in blood O2 and
CO2 transport.
Christian Bohr (1855-1911)
- Myers RE (1972) Two patterns of perinatal brain damage and their conditions of
occurrence. American Journal of Obstetrics and Gynecology 112:246-276 - White A, Handler P, Smith EL (1968) Principles of Biochemistry, fourth edition. New York:
McGraw-Hill. - Jensen FB (2004) Red blood cell pH, the Bohr effect, and other oxygenation-linked
phenomena in blood O2 and CO2 transport. Acta Physiol Scand.182:215