Distribution and characterization of immunoreactive adrenomedullin in human tissue and plasma

Abstract

A specific and sensitive radioimmunoassay for human adrenomedullin has been developed and distribution and characterization of immunoreactive adrenomedullin in human tissue were investigated. The radioimmunoassay specifically recognizes its carboxyterminal region and half maximal inhibition of binding of radioiodinated adrenomedullin(40–52)NH₂ was observed at 11 . Immunoreactive adrenomedullin was abundant in adrenal medulla (47.7 ± 26.1 , mean ± S.D.) and was ubiquitously found in all tissue examined. The mean plasma concentration of adrenomedullin in three normal individuals was 17.2 ± 6.4 (mean ± S.D.). By analysis with reverse‐phase high‐performance liquid chromatography coupled with the radioimmunoassay, most immunoreactive adrenomedullin in the adrenal medulla, atrium and lung was found to be adrenomedullin(1–52)NH₂.