IGF-I mRNA Localization in Trigeminal and Sympathetic Nerve Target Zones During Rat Embryonic Development
In recent years evidence has accumulated suggesting that insulin-like growth factors may have significant autocrine or paracrine roles in regulating the rate of growth or state of differentiation of various types of normal and tumorous tissue (1,2). A paracrine/autocrine role for insulin-like growth factor-l (IGF-I) in embryonic development has been suggested by the following observations. IGF-I is secreted by cultured fetal cells and explants and binds to specific receptors in fetal tissue (3,4). IGF-I immunoreactivity is low in fetal serum (5) but both IGF-I immunoreactivity and mRNA are detected in fetal tissues during the course of gestation (6-11). The presence of the type-l IGF receptor during embryogenesis has been demonstrated by binding studies (12,13) and by detection of receptor mRNA (11,14).
KeywordsDorsal Root Ganglion Trigeminal Ganglion Sympathetic Ganglion Sympathetic Innervation Target Zone
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