THE UNIVERSITY OF MANITOBA STUDIES ON OVINE PLACINTAL ...

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size, corresponding to the molecular weights of i9,500 to
2l,500. Agaìn a smaìl amount of contaminat.ing proteins were
apparent by this technique. Two bands were seen in the gel ,
the minor one is approximateìy l0% of the major band based
on the intensÍty of the stain.
In summary, ana'lysis of the opl preparat.ion
upon electrophoresis revealed that it t,ras not homogeneous.
The purlty of the oPL preparation is estÍmated to be approximately
80-90%. Molecu'lar weight estimation of opl is in the range of
19,500 to 2l ,500.
Dispìacement curve of oPL in the rad.i oreceptora s say for growth
hormone (RRA-GH) uslng rabbit tissue-
ln this assay, we empl oyed l2st-oeH äs tracer
and standard,respectìvely. The reason that we did this is that
oGH exhibits on'ly somatotropic and no lactogen.ic activity,
whereas hGH produces both activities in the receptor assays
(Shiu et al ,1973 and Tsushima et al ,.l973). Therefore, by using
125I-oeH and oGH as tracer and standard respectiveìy, we are
more confident of the estimate of growth hormone-like potency
of oPL.