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Human Y‐79 Retinoblastoma Cells Exhibit Specific Insulin Receptors
Author(s) -
Saviolakis George A.,
Kyritsis Athanassios P.,
Chader Gerald J.
Publication year - 1986
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1986.tb02832.x
Subject(s) - proinsulin , insulin , receptor , insulin receptor , retinoblastoma , biology , endocrinology , medicine , insulin receptor substrate , chemistry , microbiology and biotechnology , biochemistry , insulin resistance , gene
The presence of insulin receptors was investigated in human Y‐79 retinobastoma cells grown in suspension culture. The binding of [ 125 I] insulin to these cells was time, temperature, and pH dependent, was competed for by insulin and proinsulin but not other peptides, and was inhibited by antibodies against the insulin receptor. The Scatchard plot of insulin competition data was curvilinear and was resolved into a high‐affinity ( K D ∼0.5 × 10 ‐ ‐ 9 M)/low‐capacity (∼3,000 sites/cell) and a low‐affinity ( K D ∼ 1 × 10 ‐ ‐ 7 M )/high‐capacity (∼155,000 sites/cell) component. Negative cooperativity was not found, in agreement with other studies in rodent neural cells. However, in contrast to studies with rodent cells, insulin specifically down‐regulated its receptor on human Y‐79 cells after prolonged exposure. In conclusion, these data show for the first time the presence of specific insulin receptors in human Y‐79 retinoblastoma cells. Because these cells were previously shown to have several characteristics typical of neural cells, we propose their use as a model to study the effects of insulin on neural and retinal tissues of human origin.