Serum protein synthesis by the fetal rat.

Injection of C(14)-labeled amino acids intraperitoneally into rat fetuses in utero results in greater labeling of fetal serum proteins than when the amino acid is injected into the mother. Maternal partial hepatectomy leads to only minimal changes in serum protein synthesis. Rat fetuses synthesize at least some of their serum proteins during the last 3 days of gestation.