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Fractional protein synthesis rates of skin proteins are dramatically decreased in fed pigs during the postnatal development
Author(s) -
Yang Xiaojian,
Fan Ming Z
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a160-b
Subject(s) - protein biosynthesis , biology , chemistry , medicine , andrology , biochemistry
We investigated the postnatal changes in skin protein fractional synthesis rates (FSR) and their correlations with serum levels of hormones (insulin, growth hormone and cortisol), [growth factors insulin‐like growth factor‐I (IGF‐I) and glucagon‐like polypeptide‐2 (GLP‐2)] and plasma concentrations of free amino acids (AA) in fed pigs. Thirty‐six purebred Yorkshire gilts were used for sampling at d 1, 4, 6, 12, 20 and 28 (1 wk post‐weaning) of age. These pigs received an intraperitoneal injection of a flooding dose of Phe containing L‐[ring‐2H5]Phe (40 molar%) in saline. Serum samples prior to the tracer injection and plasma and skin samples at 30 min post‐injection were collected for the determinations of tracer Phe enrichments by GC‐MS, free AA by HPLC, and hormones and growth factors by RIA. Tracer Phe enrichments in the plasma and skin free AA pools were 26–27 molar%. Skin protein FSR (%/d) were 22.0, 16.1, 19.9, 11.0, 9.6, and 3.0 at the ages of d 1, 4, 6, 12, 20 and 28, respectively, with a 7‐fold decrease (P<0.05) from d 1 to 28. Of all the hormonal factors examined, postnatal changes of FSR were (P<0.05) positively correlated with serum insulin concentrations and negatively related with serum GLP‐2 levels. Postnatal changes of skin FSR were positively correlated (P<0.05) with the plasma concentrations of Asn, Gln, His, Leu, Phe, Ser, Tyr and Val (r=0.33–0.58) and negatively correlated (P<0.05, r=−0.42) with Gly. These results suggest that skin protein FSR decreases rapidly in fed pigs during the postnatal development and this reduction is well associated with some extracellular free AA concentrations as well as serum insulin and GLP‐2 levels. Supported by NSERC and OMAF of Canada.