Distribution and characterization of immunoreactive adrenomedullin in human tissue and plasma

TLDR

The study developed a specific, sensitive radioimmunoassay for human adrenomedullin and used it to map its distribution and characterize its presence in human tissues and plasma. The assay, which targets the carboxy‑terminal region and shows half‑maximal inhibition at 11 nM, was combined with reverse‑phase HPLC to identify adrenomedullin(1–52)NH₂ as the predominant immunoreactive form in tissues. Immunoreactive adrenomedullin was abundant in the adrenal medulla, present in all examined tissues, and measured at 17.2 ± 6.4 pg/mL in normal plasma, with adrenomedullin(1–52)NH₂ being the major form in adrenal medulla, atrium, and lung.

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)NH 2 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)NH 2 .