Biochemical and histological studies were
undertaken of non -pregnant and pregnant rats
maintained on diets substantially free from
methionine and choline. The results of these
investigations were applied to the interpretation
of measurements made on the blood and urine of
normal and toxaemic pregnant 'omen, and were used
in the study of the histological sections of the
tissues of a number of maternal deaths.
The following conclusions were reached:
(1) For the rat, a severe deprivation of
choline and methionine produces a diminished
excre-Lion of these substances but does not
alter the composition of the blood or the
tissues of the body, except for a reduction
of the plasma protein concentration.
(2) Such a depletion produces significant
histological changes only in the liver,
kidney, and the mammary tissue of the pregnant
animal, and of these, the liver changes are the
most prominent. They consist of a variable
admixture of fatty degeneration, and
rarefaction of the cytoplasm of the liver
cells, and are the most sensitive index of this
specific depletion; they exist when no other
pathological changes can be found.
(3) Lactation in the rat is inhibited in the
absence of adequate supplies of choline and
methionine, and it is probable that methionine
is the important factor.
(4) In humans, a raised choline and methionine
excretion not correlated with toxaemic
manifestations, was found in the pregnant
state, and is regarded as further evidence of
defective re-absorption by the renal tubules
at this time.
(5) Liver sections from seven normal pregnant
women and five toxaemic pregnant women show no
evidence of fatty change and it is therefore
unlikely thati a shortage of choline is an
important feature of eclampsia. Changes in
the liver cells which are present in
eclamptics, but not present in the liver
sectiions of normal pregnant women, however,
suggest that a general protein depletion may
well play an important part in precipitating
the development of this condition.