Secretion of insulin-like growth factor II into milk

• Published in: Biochemical and biophysical research communications Vol. 183; no. 3; p. 1230
• Main Authors: Prosser, C G, Fleet, I R
• Format: Journal Article
• Language: English
• Published: United States 31-03-1992
• Subjects: Animals; Female; Goats; Infusions, Intra-Arterial; Insulin-Like Growth Factor I - metabolism; Insulin-Like Growth Factor II - metabolism; Mammary Glands, Animal - metabolism; Milk - metabolism; Time Factors
• ISSN: 0006-291X
• DOI: 10.1016/S0006-291X(05)80322-5

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.