Receptor autoradiographic localization of insulin-like growth factor-I (IGF-I) binding sites in human fetal and adult adrenal glands.
We report here the first evidence of insulin-like growth factor-I (IGF-I) binding sites in human fetal and adult adrenal glands, obtained at autopsy. Sections of tissue were incubated with 0.1 nM [125I]IGF-I and analyzed using [3H]Ultrofilm autoradiography with image analysis coupled to computerized microdensitometry. Specific binding sites of [125I]IGF-I were found to be localized in the definitive zone, fetal zone, and fetal medulla of the fetal adrenal glands. In the adult adrenal glands, the entire cortex and medulla were specifically labeled with [125I]IGF-I. Specific binding obtained at a concentration of 0.1 nM [125I]IGF-I to areas in the fetal and adult human adrenal glands was competitively displaced by unlabeled IGF-I, with an IC50 value of 0.34-2.54 nM, and 0.38-0.73 nM, respectively, whereas insulin was much less potent in displacing the binding. Acquisition of this knowledge will aid in studies on cell growth and steroid-catecholamines biosynthesis of the human adrenal gland.
Shigematsu
K
K
Department of Pathology, Nagasaki University School of Medicine, Japan.
Niwa
M
M
Kurihara
M
M
Yamashita
K
K
Kawai
K
K
Tsuchiyama
H
H
D000302:Adrenal Cortex / Q000378:metabolism; D000311:Adrenal Glands / Q000196:embryology / Q000378:metabolism*; D000313:Adrenal Medulla / Q000378:metabolism; D000368:Aged; D001345:Autoradiography / Q000379:methods; D005865:Gestational Age; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000378:metabolism*
D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I