Characterization of neuropeptides extracted from canine intestine. Neuropeptides 1993 Jun;24(6):359-65
Date
06/01/1993Pubmed ID
7688877DOI
10.1016/0143-4179(93)90007-wScopus ID
2-s2.0-0027175346 (requires institutional sign-in at Scopus site) 6 CitationsAbstract
Quantitative determination of neuropeptides in biologic tissues by radioimmunoassay requires both an efficient extraction of neuropeptides as well as maintenance of immunochemical reactivity. Vasoactive intestinal peptide, substance P, and met5-enkephalin were chosen for this study because they are neuropeptides which appear to be involved in multiple physiologic systems. Since all three neuropeptides have a methionine residue within their amino acid sequence, oxidation of methionine to methionine-sulfoxide during the extraction process could diminish their immunochemical reactivity. Multiple factors that might be important in extracting these neuropeptides from canine intestine, including pH of the solvent, tissue homogenization, heating, and addition of enzyme inhibitors, were examined. Concentrations of vasoactive intestinal peptide-like immunoreactivity and substance P-like immunoreactivity were significantly higher in acidic solvents, and tissue homogenization appeared to increase the concentrations of these two neuropeptides. Substance P-like immunoreactivity was increased by heating after tissue homogenization, suggesting heat-induced denaturation of tissue enzymes liberated by homogenization. Separation of acidic tissue extracts by high performance liquid chromatography followed by radioimmunoassay for all three neuropeptides revealed minor acid-induced oxidation of substance P. These results should be useful for planning the extraction of these three neuropeptides from other tissues.
Author List
Koch TR, Otterson MF, Roddy DR, Go VLAuthor
Mary F. Otterson MD Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AcetatesAcetic Acid
Animals
Chromatography, High Pressure Liquid
Dogs
Enkephalin, Methionine
Hot Temperature
Hydrochloric Acid
Hydrogen-Ion Concentration
Intestines
Oxidation-Reduction
Radioimmunoassay
Solvents
Substance P
Vasoactive Intestinal Peptide