title: Retention of plasma somatomedin activity in the foetal rabbit following decapitation in utero.
abstract: One rabbit foetus within each litter was decapitated in utero on day 24 of gestation. Plasma somatomedin activity and costal cartilage metabolism were studied 5 days later in the experimental foetuses and control litter-mates. Somatomedin was assayed by the uptake of [35S]sulphate in vitro into costal cartilage from intact foetuses. Uptake was proportional to logarithmic increases in the concentration of both foetal and maternal rabbit plasma. The mean (+/- 1 S.D.) somatomedin activity of four plasma pools, each pool being derived from the intact foetuses within each of four litters, was 1.3 +/- 0.3 compared with a potency of unity for the reference pool of maternal plasma. The plasma somatomedin activity of decapitated foetuses did not differ significantly from that of control litter-mates when analysed by rank test, but the costal cartilage of decapitated foetuses took up less [35S]-sulphate in basal medium when compared with that of intact litter-mates. The headless body weight of the decapitated foetueses did not rank in a position significantly different from the one expected. The concentration of plasma growth hormone in the decapitated foetuses was less than 5 ng/ml and that of the intact foetuses was more than 157 ng/ml. It is concluded that plasma somatomedin in the rabbit foetus is not dependent on foetal growth hormone.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002356:Cartilage / Q000196:embryology / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D013006:Growth Hormone / Q000097:blood; D007016:Hypophysectomy; D011247:Pregnancy; D011817:Rabbits; D013002:Somatomedins / Q000097:blood*; D013431:Sulfates / Q000378:metabolism
chemical_list: D013002:Somatomedins; D013431:Sulfates; D013006:Growth Hormone