This is an attempt to answer Jeremy Cohen's question, "Is it true to
say the liver obtains the majority of its oxygen requirement from the
portal rather than the hepatic arterial supply? If this is the case is
there a reason; it would seem to be illogical."
Surprising, but apparently true.
I'm far from being an expert on this, but I asked a colleague, Maria
Luz Cardenas, and she directed me to Louis Hue at Louvain
(hue at horm.ucl.ac.be), who confirmed what the question implies. The
appropriate text for this is B. D. Ross (Clarendon Press, Oxford,
1972), which contains useful information around pp. 144-145. Some
relevant quotations from this book are as follows:
"There are two sources of blood supply to the liver, the portal vein
(80%) and the hepatic artery (20%)"
and
"The hepatic artery provides only a minor part of the total blood
which is received by the liver. The remainder, various estimated at
66-86% (Fisher 1963), is derived from the splanchnic bed, via the
hepatic portal vein, and is relatively desaturated of oxygen. However,
an oxygen content of only 3.3 volumes % below that in the arterial
circuit is observed in the portal venous blood of the dog. The liver
therefore receives oxygen in considerable excess of its requirements
from this source."
Regards,
Athel Cornish-Bowden (athel at ir1cbm.cnrs-mrs.fr)
