Serum somatomedin C, bioassayable growth-promoting activity (thymidine activity), and transferrin in human fetuses: in utero study.
Serum somatomedin C, thymidine uptake stimulating activity, and transferrin were measured in fetal blood collected by ultrasound-guided puncture of umbilical vessels in utero during prenatal assessment for mother-to-fetus transmissible infections. Serum somatomedin C and transferrin were measured by immunoassay. Thymidine activity was measured by assay of [3H]thymidine incorporation into lectin-activated human lymphocytes. Studies were conducted in 48 healthy fetuses at gestational ages 21-28 wk. From 21-24 to 25-28 wk, serum somatomedin C significantly increased from 0.05 +/- 0.06 to 0.24 +/- 0.03 U/ml, while thymidine activity significantly decreased from 1.41 +/- 0.15 to 0.95 +/- 0.06 U/ml. Transferrin levels did not change. These data suggest that the humoral control of fetal growth at midpregnancy involves mechanisms other than direct regulation by somatomedin.
D001681:Biological Assay; D005260:Female; D005312:Fetal Blood / Q000502:physiology*; D005865:Gestational Age; D006133:Growth Substances / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000097:blood*; D008214:Lymphocytes / Q000378:metabolism; D011247:Pregnancy; D013002:Somatomedins / Q000097:blood*; D013936:Thymidine / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism*
D006133:Growth Substances; D013002:Somatomedins; D014168:Transferrin; D007334:Insulin-Like Growth Factor I; D013936:Thymidine