Journal
JOURNAL OF NUTRITION
Volume 139, Issue 9, Pages 1677-1684Publisher
OXFORD UNIV PRESS
DOI: 10.3945/jn.108.103549
Keywords
-
Categories
Funding
- Michigan State University Agricultural Experiment Station
Ask authors/readers for more resources
To test the hypothesis that under restricted and surfeit protein intake the mammary gland undergoes adaptive regulation, changes in mammary tissue mRNA abundance of cationic amino acid (AA) transporter (CATH, CAT-2B, alanine/serine/cysteine/threonine transporter 1 (ASCT1), and broad specificity transporter for neutral and cationic AA (ATB(0,+)), and CAT-1 protein abundance were investigated at 2 stages of lactation. Eighteen sows were allocated to a 2 X 3 randomized incomplete block design with 2 stages of lactation (early and peak) and 3 protein levels: deficient (D), adequate (A), or in excess E) of lactation requirement. In early lactation, compared with A, sows fed E had lower (P = 0.05) piglet growth rate and sows fed D or E had lower P:5 0.05) casein yield. In early lactation, piglet growth rate and milk protein and casein yield increased from D to A and decreased from A to E (quadratic, P = 0.095, P < 0.05, and P < 0.01, respectively). Protein intake did not affect CAT-1, ASCT1, ATB(0,+) mRNA abundance, or CAT-1 protein level. Overall, CAT-2B mRNA abundance decreased linearly with increasing protein intake (P < 0.05). Compared with A, E decreased CAT-2B mRNA abundance (P < 0.05). Compared with early lactation, peak lactation did not increase CAT-1 mRNA abundance or relative CAT-1 protein content, but increased abundance of ASCT1 and ATB(0,+) mRNA (P < 0.01). Mammary CAT-2B appears to be adaptively regulated in vivo at the transcription level, whereas ASCT1 and ATB(0,+) mRNA abundances are associated only with stage of lactation. Neither protein intake nor stage of lactation affects porcine mammary CAT-1 gene expression in vivo. J. Nutr. 139: 1677-1684, 2009.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available