Rapid radioimmunoassay for guanosine 3',5'-cyclic monophosphate using tritiated ligand.
A radioimmunoassay procedure for guanosine 3',5'-cyclic monophosphate (CGMP) is described. The procedure is based on competitive binding between [3H]CGMP and non-radioactive CGMP, with separation of bound and unbound CGMP by Millipore filtration. The binding reaction showed very high specificity to CGMP, had a broad pH optimum, and reached equilibrium within a short time. A simple procedure for the pruification of assay samples using Dowex AG 50W-X2 resin is also described. CGMP contents in urine samples were assayed without purification. Injection of glucagon into healthy human volunteers resulted in a small but significant reduction in urinary CGMP level, whereas CAMP excretion increased dramatically.
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D000242:Cyclic AMP / Q000652:urine; D006152:Cyclic GMP / Q000032:analysis* / Q000378:metabolism / Q000652:urine; D005934:Glucagon / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008851:Micropore Filters; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D012492:Salts / Q000494:pharmacology; D014316:Tritium
D012492:Salts; D014316:Tritium; D006160:Guanosine Triphosphate; D005934:Glucagon; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D006152:Cyclic GMP