Secretion of insulin-like growth factor II into milk.
125I-labeled insulin-like growth factor II (IGF-II) was infused directly into the pudic artery supplying one gland of lactating goats (n = 4). Maximum specific activity for [125I]IGF-II transferred into milk from the infused gland was reached 60 min after that in plasma and was 2.5 fold greater than in milk from the non-infused gland. Inclusion of either 67.5 nmoles unlabeled IGF-II or IGF-I had no influence on the amount or pattern of secretion of [125I]IGF-II into milk from either gland. While the temporal pattern of secretion of [125I]IGF-II into milk was consistent with a transcellular mechanism of transfer, the lack of competition by unlabeled IGF-II or IGF-I suggests a non-specific mechanism is operable, which contrasts to secretion of IGF-I.
Prosser
C G
CG
AFRC Institute of Animal Physiology and Genetics Research, Cambridge, U.K.
Fleet
I R
IR
D000818:Animals; D005260:Female; D006041:Goats; D007261:Infusions, Intra-Arterial; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008892:Milk / Q000378:metabolism*; D013997:Time Factors
D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II