Premium
Basic Fibroblast Growth Factor (bFGF) Immunoreactivity Is Present in Chromaffin Granules
Author(s) -
Westermann Reiner,
Johannsen Marianne,
Unsicker Klaus,
Grothe Claudia
Publication year - 1990
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1990.tb08850.x
Subject(s) - basic fibroblast growth factor , adrenal medulla , antiserum , polyclonal antibodies , medulla , biology , endocrinology , medicine , chromaffin cell , immunocytochemistry , microbiology and biotechnology , growth factor , antibody , biochemistry , immunology , receptor , catecholamine
Basic fibroblast growth factor (bFGF) has recently been isolated from bovine adrenal glands. Immunohistological data revealed its presence in both adrenal cortex and adrenal medulla. Using immuno‐electronmicroscopy, we found that in medullary chromaffin cells bFGF‐immunoreactivity is localized in the secretory granules. Immuno‐reactivity also was observed by electronmicroscopy in isolated granules. Western blot analysis revealed the presence of the typical 18‐kDa bFGF and additional immunoreactive materials with molecular masses of ∼ 24, 30, and 46 kDa in whole bovine adrenal, and in cortex and medulla. Similar results were obtained with proteins from bovine chromaffin granules, with the following two exceptions: the 46‐kDa immunoreactivity was found to be highly enriched when compared with medulla or cortex, and the 18‐kDa band could be detected with only an antiserum against a synthetic peptide comprising the 24 NH 2 ‐terminal amino acids of bFGF, and not with an antiserum against purified bovine pituitary bFGF. All fractions enriched for bFGF‐immunoreactivity showed neurotrophic activity for chick ciliary ganglion neurons, which could be blocked by antibodies. These results demonstrate for the first time the localization and occurrence of bFGF in a cellular secretory organelle, and present further evidence for the existence of higher molecular weight immunoreactive forms of bFGF.