M F Towle | PubMed Health

PubMed1992

Function-blocking antibodies against cholinergic neuronal differentiation factor.

Cholinergic neuronal differentiation factor, CDF, causes a transition from noradrenergic to cholinergic phenotype in cultured sympathetic neurons. Moreover, its identification with leukemia inhibitory factor has shown that CDF is a multifunctional cytokine. To examine the physiological role of CDF and to further elucidate the as yet unknown effects of CDF on the nervous system, two kinds of function-blocking antibodies were generated. One type, raised against whole native CDF, completely blocks CDF activity, whereas the other type, raised against a synthetic peptide corresponding to the N-terminal amino acid region of CDF, blocks activity partially. All three anti-CDF and two antipeptide polyclonal antibodies tested in this study significantly inhibit CDF function.

Animals↗

PubMed1991

Immunoaffinity purification and dose-response of cholinergic neuronal differentiation factor.

A glycoprotein from heart cell-conditioned medium, cholinergic neuronal differentiation factor (CDF), causes a transition from noradrenergic to cholinergic phenotype in cultured rat sympathetic neurons. Although the transition has been known to occur in a dose-dependent manner and CDF has been purified, the examination of a complete dose-response of neurons to CDF has not been possible because sufficient quantities of pure CDF have not been available. A complete dose-response curve is essential for evaluating the biological response of the neurons, for assessing the physiological role of CDF and for understanding the mechanism of action of CDF. We report here an immunoaffinity-purification procedure for CDF with a 73.1% recovery using antibodies raised against a synthetic peptide homologous with the N-terminal region of CDF. This method produced pure CDF in quantities sufficient for examination of the full dose-response range of the neurons. Our main findings are the following. The dose-responses of acetylcholine and catecholamine metabolisms to CDF are different, although the same molecule affects both transmitters. While the half-maximal concentrations for acetylcholine induction (0.20 nM) and for catecholamine suppression (0.28 nM) are similar, the response of catecholamine metabolism begins slowly and saturates at a CDF concentration (5-20 nM) considerably higher than that of acetylcholine (0.6 nM). This may indicate that CDF affects multiple processes in catecholamine metabolism.

Amino Acid Sequence↗