in the in vitro monolayer pituitary cell culture system somatomedin-c and igf-i are practically equipotent to inhibit the secretion of growth hormone stimulated by hypothalamic growth hormone releasing factor ( grf ) or the synthetic peptide hpgrf-44 ( 3-200 x 10 ( -12 ) m ) .
C0020663
hypothalamic
C0037668
growth hormone releasing factor