Quantitation of Neuropeptides by Radioimmunoassay

The current growth of interest in peptides arising within, or having biological effects on, the nervous system has resulted in a broader application in neurobiology of radioimmunoassay (RIA), a technique that combines great simplicity and sensitivity with the inherent specificity of immunological reactions. Two general strategies in which RIA is a central tool for the study of neuropeptides can be developed, each having its own special considerations and problems. In the first, RIA procedures already developed for well-characterized peptides from other anatomical sites in the same or different species can be applied to the detection of identical or immunologically related peptides within the nervous system. The second approach involves the identification of newly described neuropeptides, development of RIA systems to assist in further characterization, and/or purification of the peptides and then application to the study of their distribution and physiological role. This chapter will deal with specific problems involved in the application of each of the general strategies outlined above. No attempt will be made here to