THE UNIVERSITY OF MANITOBA STUDIES ON OVINE PLACINTAL ...

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were obtained from pregnant and non-pregnant ewes-. Fr.g. fOA shows that oGH
inhlbited the blndïng of opl to corpus luteum in a para.lleì nanner,
whereas, oPRL and oLH did not fnhibit. Figure 208 shows that in the
ovary' oPRL and oLH slightìy inhibited the binding of opL in a non-
parallel manner, and oGH caused an inhibition of 20-30i. whJch ls at
least l0% lower than that observed in other tissues. Scatchard plots
of data obtained agaÍn are shown.
Liver
Figure 2l shows the inhibition of blnding by ovine pL,
GH, PRL, and LH to uterine preparations (obtained from non_pregnant
ewes) and to the preparations of fetal liver obtained from a mature
fetus at .l30-135 days of gestation. In both tissues (figure 2.lA for
uterus and B for fetal llver), onìy GH inhibÍted the binding of pL
whereas PRL and LH did not.
l^le have studied the binding of ovine proìactin to 7g0 x g,
.'5,000 x g, ðnd .'00,000 x g fractions of various ovine tissues. Specific
bindÍng of ì25FopRLwas less than 3l / mg proteln in all fractions of
the following tissues frrom the ewe (both pregnant and non_pregnant):
mammary gland, adrenal , kidney, spleenr pancreas, lung, heart, skeletal
mu6cle' brain(cortex)' and uterus ( non -pregnant and 20-60 days of gestation).
Less than 3 % specific binding was aiso found ln severaì fetal tissues