(1) A new and reliable method has been found for the
estimation of fructose in blood, which is not interfered with
to any great extent, by glucose. It is suggested that this
method might prove to be a valuable aid in the elucidation of
further facts bearing on the utilisation of fructose in the
(2) This method has been employed to follow the fate of
ingested and injected fructose in rabbits.
(3) The results obtained suggested that fructose was as
efficient, if not more so, than glucose in stimulating the
secretion of insulin.
(4) This conclusion was tested by studying the blood
sugar curves obtained after ingestion of glucose, and comparing them, with curves obtained after a similar oral dose
of glucose was followed by an injection of fructose.
(5) The conclusion that fructose was more effective, in
this direction, than glucose was tested by comparing the curves
obtained above, with curves given after oral ingestion of glucose
was followed by intravenous injections of glucose.
(6) These results and the work of other authors suggest
the hypotheses: that conversion to glucose does occur slowly
in normal animals; that the
takes place is the liver (although some evidence is given indicating
that other tissues can effect the same change); that this
conversion, of fructose to glucose, is independent of insulin;
and that direct synthesis of glycogen from fructose does not
(7) This theory is discussed in relation to the work of