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).
KeywordsTyrosine Retina Hematoxylin Eosin
Unable to display preview. Download preview PDF.
- 5.Daughaday, W.H., Parker, K.A., Borowsky, S., Trivedi, B. and Kapadia, M. (1982) Measurement of somatomedin-related peptides in fetal, neonatal and maternal rat serum. Endocrinology 110:575–581.Google Scholar
- 10.Beck, F., Samani, N.J., Penschow, J. D., Thorley, B., Tregear, G.W. and Coghlan, J.P. (1987) Histochemical localization of IGF-I and -II mRNA in the developing rat embryo. Dev. 101:175–184.Google Scholar
- 12.Girbau, M., Bassas, L., Alemany, J. and de Pablo, F. (1989) In situ autoradiography and ligand-dependent tyrosine kinase activity reveal insulin receptors and insulin-like growth factor receptors in prepancreatic chicken embryos. Proc. Natl. Acad. Sci. USA 86:5868–5872.PubMedCrossRefGoogle Scholar
- 19.Heumann, R., Korsching, S., Scott, J. and Thoenen, H. (1984) Relationship of NGF and its mRNA in sympathetic ganglia and peripheral target tissues. EMBO 3:3183–3189.Google Scholar