THE UNIVERSITY OF MANITOBA STUDIES ON OVINE PLACINTAL ...

IBB
OVINE CHORI0NIC MEMBRANES ln vltro
Fígure 37 shows the percentage or l,2st_op¡- preclpltated
by 20 ul of anti-opl in the presence of lncreasÍng anounts.of
unlabeled oPL, indicating that the equivarence zone of this precipitatìon
curve is between 500 to 2000 nanograrn (ng). tf less than SOOng of opl was
present, incomplete precipitation occurrud. l,lhen I microgram (ug) of
unlabeled oPL was added as carrler to the reaction mixture after overnÍght
{ncubation, Bb-901 of l25I-opL was precipitated ,, , .. , provlded
that the amount of opl Ín the lnitial solutfon did not exceed 2 ug.
In subsequent precipitatÍon studies of 3H_opL, we first determîned the
total amount of opl by RIA, and then added carrîer opl lnto the
incubation medium ensuring that the opL amount did not exceed 2 ug.
Gestational period
Table VIII shows the amount of radioactivity which êould be precipitated
by TCA and antf-opl ln various lncubatÍon media. It is apparent from
this tabte that ovine chorronlc membranes nnere abre to.synthesÍze and
to secrete opL as early as 26 days of.the gestational period.
Ge] Fi I trä
ion Medium on Grl00
The distribufion of protein and opt¡. when a,n aliquot
(3 ml) of 24 h incubation medium was fractionated ona Sephadex G_100