Association of I 131 -Labeled Lactogenic Hormone with Cytoplasmic Nucleoprotein of Mammary Gland Cell. ∗

Abstract

Summary

Studies have been carried out with lactogenic hormone labeled with radioactive iodine in pseudo-pregnant rabbit mammary gland which indicate that the labeled hormone becomes associated with the cytoplasmic particulate nucleoprotein. Other data suggests that the particulate lipids are probably not involved in the lactogenic hormone-particulate association. These findings have been discussed in terms of their relation to the shift in synthesis which occurs in the mammary gland with the initiation of lactation.