TY - JOUR
T1 - Localization and structural charcterization of insulin-like growth factor receptors in mammalian retina
AU - Ocrant, Ian
AU - Valentino, Karen L.
AU - King, Michael G.
AU - Wimpy, Thomas H.
AU - Rosenfeld, Ron G.
AU - Baskin, Denis G.
PY - 1989/11
Y1 - 1989/11
N2 - Insulin-like growth factors (IGFs) are peptide mitogens, structurally related to insulin, whose biological actions in the CNS are incompletely known. The retina is largely uncharacterized with respect to IGF receptors. We, therefore, studied IGF receptors in bovine and murine retinal tissues by immunohistochemistry, autoradiographic localization, and affinity labeling. Notable IGF-II receptor immunoreactivity was found in retinal pigment epithelium (RPE), with intermediate levels in choroid, low levels in the inner and outer plexiform layers and outer nuclear layer, and very low levels in other regions. Autoradiographic localization using [125I]IGF-II confirmed the IGF-II receptor immunohistochemistry. Autoradiographic local ization using [125I]IGF-I labeled the nuclear layers and the photoreceptor region. Affinity labeling disclosed differences in the apparent mol wt of IGF-I and IGF-II receptors from bovine eye tissues and those from liver and brain. IGF-I receptor asubunits (the IGF-binding subunit) migrated at: liver, 139,000; brain, 125,000; RPE, 125,000 and 135,000 (two sizes); and retina, 125,000 and 135,000. IGF-II receptors migrated at: liver, 245,000; brain, 235,000; RPE, 240,000; and retina, 230,000. We conclude that mammalian retina contains both IGF-I and -II receptors, which differ from those found in other tissues and have a characteristic spatial distribution within the retina.
AB - Insulin-like growth factors (IGFs) are peptide mitogens, structurally related to insulin, whose biological actions in the CNS are incompletely known. The retina is largely uncharacterized with respect to IGF receptors. We, therefore, studied IGF receptors in bovine and murine retinal tissues by immunohistochemistry, autoradiographic localization, and affinity labeling. Notable IGF-II receptor immunoreactivity was found in retinal pigment epithelium (RPE), with intermediate levels in choroid, low levels in the inner and outer plexiform layers and outer nuclear layer, and very low levels in other regions. Autoradiographic localization using [125I]IGF-II confirmed the IGF-II receptor immunohistochemistry. Autoradiographic local ization using [125I]IGF-I labeled the nuclear layers and the photoreceptor region. Affinity labeling disclosed differences in the apparent mol wt of IGF-I and IGF-II receptors from bovine eye tissues and those from liver and brain. IGF-I receptor asubunits (the IGF-binding subunit) migrated at: liver, 139,000; brain, 125,000; RPE, 125,000 and 135,000 (two sizes); and retina, 125,000 and 135,000. IGF-II receptors migrated at: liver, 245,000; brain, 235,000; RPE, 240,000; and retina, 230,000. We conclude that mammalian retina contains both IGF-I and -II receptors, which differ from those found in other tissues and have a characteristic spatial distribution within the retina.
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U2 - 10.1210/endo-125-5-2407
DO - 10.1210/endo-125-5-2407
M3 - Article
C2 - 2551648
AN - SCOPUS:0024429269
SN - 0013-7227
VL - 125
SP - 2407
EP - 2412
JO - Endocrinology
JF - Endocrinology
IS - 5
ER -