Immunochemical characterization of neurotensin-like peptides in chicken

Using radioimmunoassay and 3 region specific antisera toward bovine neurotensin (NT), the NT-like peptides in chicken have been shown to differ from NT but to strongly resemble its COOH-terminal region. Three substances were identified, one of which resembled NT biologically and appeared to share 7 or 8 of its COOH-terminal residues. The two other peptides were smaller than NT but seemed to possess 4–6 residue homologies with it. Tissue distribution studies indicated that the chicken pancreas and thymus had unusually high levels of this material (>200 fold that in rat) and that the 3 substances were distributed differently in tissues. Chromatographic studies showed that the peptides obtained from brain, intestine, thymus, and pancreas were similar. These results, demonstrating evolutionary conservation of the COOH-terminal region of NT, are in keeping with the known importance of this region for biological activity. These findings also suggest the existence of an NT-family of peptides serving multiple biological roles.     

Stimulation of collagen synthesis in fibroblast cultures by superoxide.

Exposure of diploid fetal human fibroblasts (IMR-90) to superoxide generated by dihydroxyfumarate resulted in increased collagen synthesis. The synthesis of type III collagen was stimulated to a greater extent than the synthesis of type I collagen. The stimulation of collagen synthesis was abolished by superoxide dismutase. Our observations suggest that superoxide may play a role in the regulation of collagen synthesis and may modulate differential collagen gene expression. These observations may explain the increased synthesis of collagen in tissues following inflammation or exposure to oxidant conditions.