THE UNIVERSITY OF MANITOBA STUDIES ON OVINE PLACINTAL ...

lJhen blood samples were taken four times daily for
days from four pregnant ewes starting at approxlmateìy day ì20
of gestation, it was found that there was no circadian variation
in serum oPL concentrafions, as shown ln Figure 2g.
oPL 'ln the I and Fetal C i rcul at
Table IV compares opl concentratîons in maternal ( perl pheral )
and in fetal sera at varÍous stages of gestation. The opl concentrations
in the fetaì sera were approximateìy nine ilmes higher ( 9.S t 5.3;
mean t SD of five sheep) than those in the maternal peripheraì sera
from day 46-70, but after day ilO-il2, fetal concentrations were
always l ower than the maternal
to approximate'ly 20?l of the maternal level .
OPL C.r..rt".ti ot
leveìs, amounti ng
Figure 29 shows opL concentrations in allantolc and amnfotic
fluid at various periods of gestation. opl was detected as early as
day l8( 2.5-3.5 ng/m'l ) in allantoic fluid and, thereafter, opL concentrations
increased to reach peak ìevels between day 3S_S0, followed by a sllght
decline in oPL concentrations throughout pregnancy. opl was detected in
amniotic ¡1ri¿ in,7 out of 9 specimens about day 40-50,but not thereafter.
0f 12 maternal urine samples collected between 110_130 days
of gestation, five had undetectable leve]s of opl (