Abstract
Lectin-purified rat brain preparations demonstrate specific [125I]-insulin and [125I]-IGF-1 binding. Insulin-stimulable tyrosine kinase activity as mesured by exogenous substrate phosphorylation was present in brain and liver lectin purified preparations with the Δ kinase activity/B/F of brain -2.5 fold greater than that of liver. Insulin-stimulable tyrosine kinase activity was abolished in liver but decreased by only -50 percent in brain after immunodepletion with antiserum which recognizes insulin but not IGF-1 receptors. Insulin and IGF-1 dose responses for phosphorylation of the immunodepleted brain preparations suggested that the remaining tyrosine kinase activity was IGF-1 receptor mediated. Thus, functional IGF-1 receptors are present in rat brain, and the doses of insulin typically used to evaluate insulin receptor tyrosine kinase activity will stimulate IGF-1 receptor tyrosine kinase activity as well.
Original language | English |
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Pages (from-to) | 532-538 |
Number of pages | 7 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 134 |
Issue number | 2 |
DOIs | |
State | Published - 29 Jan 1986 |
Externally published | Yes |