Production of antisera to des Asn28 Thr29 Homoser27-glucagon; the development of radioimmunoassay for total glucagon-like immunoreactivity in human plasma.
Antisera having a strong and strictly constant cross-reactivity for gut-GLI were raised in seven rabbits immunized with immunogen, a conjugate of BSA and des-Asn28, Thr29, Homoser27 -glucagon (CNBr-glucagon). All of the anti-CNBr-glucagon sera exhibited titer and affinity for glucagon sufficiently high enough to develop a sensitive radioimmunoassay. The relative crossreactivity of the antisera to gut-GLI was comparable to that of antiserum K-4023 which strongly crossreacted with gut-GLI. One of the anti-CNBr-glucagon sera, OAL-196, did not react with the glucagon 19-29 fragment at all. The intra- and inter-assay coefficients of variation were 3.8-5.0 and 6.0-7.3%, respectively, in the radioimmunoassay system for total GLI in human plasma using OAL-196. The fasting plasma total GLI was 374 +/- 18 pg/ml. The plasma total GLI during 50 g oral glucose load in normal subjects increased significantly, whereas the plasma IRG level measured with the anti-glucagon 19-29 serum, OAL-123, assay system was lowered. In the gastrectomized subjects, plasma total GLI measured with the present assay system elicited a marked increase following an oral glucose load. These results suggest that the radioimmunoassay using anti-CNBr-glucagon sera will be useful in measuring plasma total GLI.
D000818:Animals; D003429:Cross Reactions; D004285:Dogs; D005743:Gastrectomy; D005934:Glucagon / Q000031:analogs & derivatives / Q000276:immunology*; D004763:Glucagon-Like Peptides; D006801:Humans; D007106:Immune Sera / Q000032:analysis / Q000276:immunology*; D007114:Immunization; D007422:Intestines / Q000276:immunology; D010455:Peptides / Q000097:blood*; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*; D014020:Tissue Extracts / Q000276:immunology
D007106:Immune Sera; D010455:Peptides; D014020:Tissue Extracts; D004763:Glucagon-Like Peptides; C015236:glucagon-like-immunoreactivity; D005934:Glucagon