44
PHYSIO-CHEMICAL INVESTIGATION ON PLACENTAL FLUIDS [Vol. XXV, Part 1,
It may be suggested here that the creatinine N : total N ratio is perhaps correlated
with the growth rate during the pre-natal life.
There is always a physiological balance between the rate of secretion and of
absorption of placental fluids. The rate of increase in the amniotic and allantoic
fluids varies throughout pregnancy and amongst species. In the buffalo, the ratio
of amniotic to allantoic volume is 1 : 30 in early pregnancy and 5 :1 during mid-
pregnancy [Hafez, 1955]. In the cow, the placental fluids increase rapidly until
about the fifth month of pregnancy, after which the amount remains fairly constant
[Bergmann, 1921 ; Hammond ; 1927] ; the increase, if any, occurs in the allantoic
fluid while the amniotic fluid shows a decrease after this time. Similar is the case
in women (Minot, 1892]. In the guinea pig the amniotic fluids increase rapidly up
to the 44th day after which there is little or no further increase [Draper, 1920],
although Ibsen [1928] finds a drop at the 55-day stage with subsequent increase.
In some species such as the rabbit, the placental fluids are absorbed by the foetus.
A comparative study of the physio-chemical properties of the placental fluids
in different species correlated with their respective curve of absorption of placental
fluids throughout pregnancy would be of great interest. The presence of certain
substances in the placental fluids or certain concentrations of some substances may
indicate evolutionary changes with increase in duration of gestation in these species.
Changes in the physio-chemical properties in relation to interruption of pregnancy
would be of great academic interest in veterinary obstetrics.
Morphological evidence into the functioning of the uterus and placenta has been
gained by histochemical studies [Weeth and Herman, 1952]. It is fitting that so
vital a link in the preservation of placental mammals as the uterus and its functioning
should receive thorough investigation. It is also imperative for a more complete
knowledge of the biological mechanisms involved in an adequate intrauterine life
that all resources and techniques of the various researches be utilized. Localization
of metabolites, hormones, enzymes of pregnancy, estimates of their quantitative
variations, and interpretation of their inter-relationships in maintaining the environ-
ment of the conceptus will materially aid the understanding of pregnancy.
SUMMARY
1. The placental fluids (amniotic and allantoic fluids) were obtained from 23
pregnant uteri of Egyptian buffaloes. They represented five different stages of
the first half of pregnancy. Qualitative tests for reduced sugars, glycogen, acetone
bodies, creatinine and six amino acid tests were carried out in both fluids. Total,
amino and creatinine nitrogen were also determined.
2. The specific gravity of the fluids varied from 1.0040 to 1.0120. A slight
increase was observed in the allantoic fluids in PIV and PV uteri.
3. Reduced sugars were more abundant in the allantoic fluid than in amniotic.
4. Glycogen was absent in the allantoic and doubtful in the amniotic.
5. Acetone bodies were not detected in both the fluids.
6. Creatinine was found only in the allantoic ; if increased throughout pregnancy.
7. Deeper colour reactions were obtained for the amino acids in the allantoic
than in the amniotic fluid. The allantoic fluid contained larger quantities of tyrosine
than of amino acids of benzene ring and glycoproteins.