title: Development of an enzyme-linked immunosorbent assay for serum 11-dehydrocorticosterone in rat and mouse.
abstract: We have developed an enzyme-linked immunosorbent assay (ELISA) for serum 11-dehydrocorticosterone (4-pregnen-21-ol-3,11,20-trione). The antiserum against 11-dehydrocorticosterone 21-hemisuccinate-conjugated bovine serum albumin was raised in rabbits. As an enzyme-labeled antigen, 11-dehydrocorticosterone 21-hemisuccinate was conjugated to horseradish peroxidase. Two ELISA systems were established: one without the extraction of steroids from serum (direct method), and another that used an HPLC purification step (HPLC method). The cross-reactivity of all steroids tested against the antibody was low except cortisone (92%); however, since cortisone levels in rats and mice are negligible, cortisone does not interfere with this direct ELISA. The measurable range of serum 11-dehydrocortiocosterone in both the direct and HPLC methods was 0.3-250 ng/ml and 0.78-400 ng/ml, respectively. Both methods displayed satisfactory parallel dilution, recovery and reproducibility; moreover, the values obtained with each method significantly correlated with the alternate method. To evaluate the two ELISA systems, the serum concentrations of 11-dehydrocorticosterone in normal rats and mice were determined by these two systems. The levels in Wistar rats fluctuated from 3 to 14 weeks of age (7.8+/-2.6 ng/ml) but at 1 week (1.7+/-1.2 ng/ml) were significantly low compared to other ages. No sex differences were found in rats and mice. Further, using the proposed direct method, chronological changes of rat serum 11-dehydrocorticosterone levels after 11-dehydrocorticosterone administration have been investigated together with corticosterone levels. These results verify that the proposed ELISA for 11-dehydrocorticosterone is useful for measuring 11beta-HSD activities in combination with the determination of serum corticosterone in rats and mice.
authors.affiliation: Department of Medical Biochemistry, Kobe Pharmaceutical University. t-noriko@kobepharma-u.ac.jp
authors.forename: Noriko
authors.initials: N
authors.lastname: Tagawa
authors.forename: Nao
authors.initials: N
authors.lastname: Ikariko
authors.forename: Keiko
authors.initials: K
authors.lastname: Fukumura
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D042842:11-beta-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000284:Administration, Oral; D000367:Age Factors; D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D003345:Corticosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006735:Horseradish Peroxidase / Q000378:metabolism; D007106:Immune Sera / Q000276:immunology; D007201:Indicator Dilution Techniques; D008297:Male; D051379:Mice; D011247:Pregnancy; D011485:Protein Binding; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013997:Time Factors
chemical_list: D007106:Immune Sera; D012710:Serum Albumin, Bovine; D042842:11-beta-Hydroxysteroid Dehydrogenases; D006735:Horseradish Peroxidase; C003552:11-dehydrocorticosterone; D003345:Corticosterone