Background and purpose: Insulin-like growth factor (IGF)-1 has potent neuroprotective properties. We investigated the effects of intravenous administration of tissue plasminogen activator (tPA) on serum levels of IGF-1 and IGF-binding protein (IGFBP)-3 in patients with acute ischemic stroke.
Methods: Serum levels of total IGF-1, free IGF-1, and IGFBP-3 were measured by radioimmunoassay in 10 patients with ischemic stroke treated with intravenous tPA (0.9 mg/kg body weight) and 10 untreated controls.
Results: During tPA treatment, total IGF-1 and IGFBP-3 serum levels did not change, but there was an &70% increase in free IGF-1 serum levels from 0.98+/-0.25 at baseline to 1.69+/-0.18 nmol/L at the end of the 1-hour infusion (P=0.01).
Conclusions: Intravenous therapy with tPA enhances the bioavailability of IGF-1.