Microdialysis combined with a sensitive radioimmunoassay. A technique for studying in vivo release of neuropeptides.
Microdialysis in combination with radioimmunoassay was used to study in vivo release of neuropeptides in the rat brain. Microdialysis is a novel brain perfusion technique, by which molecules in the extracellular space may be monitored. This study describes the application to neuropeptide research. A radioimmunoassay procedure was adapted so that substance P- and neurokinin A-like immunoreactivity could be measured in samples collected during in vivo release experiments. The detection limits of substance P and neurokinin A were below 0.1 fmol/100-microliters sample and the IC50 approximately 1 fmol/sample for both peptides. Potassium, introduced via the microdialysis probe, was found to induce a concentration-dependent increase of the extracellular concentration of neurokinin A-like immunoreactivity.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D003956:Dialysis; D008297:Male; D015288:Neurokinin A; D009479:Neuropeptides / Q000032:analysis* / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000032:analysis
D009479:Neuropeptides; D013373:Substance P; D011189:Potassium Chloride; D015288:Neurokinin A