CORTICOSTEROID 11-BETA-DEHYDROGENASE OF RAT-TISSUES - IMMUNOLOGICAL STUDIES

Monospecific polyclonal antibodies to purified homogeneous rat liver corticosteroid 11β-dehydrogenase were generated in rabbits. The antibodies were immunoprecipitins, but enzyme activity was not completely suppressed in the antigen-antibody complex. Two antibody preparations, 56-125 and 56-126, used to detect 11β-dehydrogenase antigen in Western blots, generated different staining patterns for kidney, liver, brain, and heart. Using the two antibodies together, the total number of antibody-reacting components in kidney was three, and that in liver was two. Based on rates of digestion with proteases, the two prominent immunoreactive proteins in kidney appeared to be structurally or conformationally different. A prominent immunostaining component was present in stomach. Tissues that showed immunochemical evidence of 11β-dehy-drogenase antigen showed corresponding levels of 11β-dehydrogenase activity. Most active were liver, testis, kidney, and lung. Lower levels of activity were found in prostate and epididymis, brain, and reproductive tract. We conclude that 11β-dehydrog-enase is widely distributed in rat organs and is present at low levels with significant exceptions. The data indicate that 11β-dehydrogenase may occur in several enzyme forms, and that the distribution of these forms is to some extent tissue specific. © 1990 by The Endocrine Society.