title: Nerve growth factor in skeletal tissues of the embryonic chick.
abstract: This study demonstrates, via immunohistochemistry and bioassay, the presence of NGF in embryonic bone and cartilage of the chick. Embryos were killed on days 6-9 of incubation at 12 h intervals, and on days 10-18 at 24 h intervals. Paraffin-embedded sections of hind limbs or buds were immunostained with a polyclonal antibody against NGF and the biotin-avidin-horseradish peroxidase technique. Immunostaining was positive in both bone and cartilage, with cartilage staining more intensely. For bioassay, bones from the hind limbs of 9- and 12-day embryos were fast-frozen, lyophilized, and homogenized with Medium 199 (M199). Dorsal root ganglia from 8-day embryos were cultured for 24-36 h with rooster plasma, M199, and varying concentrations of bone homogenate. Significant neurite outgrowth was seen, with the greatest response elicited by 12-day bone homogenate. Addition of anti-NGF to the cultures abolished neurite outgrowth. The results indicate that NGF is present in cartilage and bone of the chick embryo; it may determine the density of sympathetic innervation to the developing skeletal tissues.
authors.affiliation: Department of Anatomy, New York University Dental Center, NY 10010.
authors.forename: S R
authors.initials: SR
authors.lastname: Frenkel
authors.forename: L A
authors.initials: LA
authors.lastname: Guerra
authors.forename: O G
authors.initials: OG
authors.lastname: Mitchell
authors.forename: I J
authors.initials: IJ
authors.lastname: Singh
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000196:embryology / Q000378:metabolism*; D002356:Cartilage / Q000196:embryology / Q000378:metabolism*; D002642:Chick Embryo; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects; D007150:Immunohistochemistry; D009414:Nerve Growth Factors / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D009414:Nerve Growth Factors