Abstract
The hormonal and metabolic factors which contribute to fetal growth are poorly understood. In the present experiments pregnant rats were continously infused from day 18 to 20 post conception with saline (S) or amino acids (AA: 2.5g/kg/day). After an overnight fast of 14 hours fetal body weight, fetal serum somatomedin (SM, porcine cartilage bioassay) and the "endogenous" fetal cartilage bioactivity were determined (=incorporation of 35SO4 into the fetal costal cartilage in response to 0, 5 or 10 per cent normal rat serum). Results: AA-compared to S-infusions increased fetal body weight (S:4.0±0.5*g, n=9; AA: 4.9±0.3*g, n=6; p<0.01), fetal SM (S:0.42±0.17 U/ml, n=9; AA:0.85±0.22 U/ml, n=6; p<0.001) and the fetal “endogenous” cartilage bioactivity (S:629±507 cpm/mg, n=33; AA:956±684 cpm/mg, n=21; p<0.01 = sum of the cpms in the presence of the various serum concentrations). Conclusions: As reported previously an increased serum somatomedin concentration, as in fetal hyperglycemic rats, may not be associated with an augmented fetal growth rate, while the results of the present study suggest that at least amino acids plus somatomedin are appropriate growth factors for the rat fetus.
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Heinze, E., Thi, C., Wagner, M. et al. The Effect of Amino-Acid-Infusions in Pregnant Rats on some Fetal Growth Parameters. Pediatr Res 15, 1549 (1981). https://doi.org/10.1203/00006450-198112000-00083
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DOI: https://doi.org/10.1203/00006450-198112000-00083