title: Source of plasma adrenomedullin in patients with pheochromocytoma.
abstract: Controversy exists as to the origin of plasma adrenomedullin (AM). To elucidate the source of plasma AM, we measured two molecular forms of AM, an active form of mature AM (AM-m) and an intermediate inactive form of glycine-extended AM (AM-Gly), by immunoradiometric assay using specific kits in two female patients with pheochromocytoma before and 3 weeks after surgery. We also measured plasma AM-m, AM-Gly, and AM-T (AM-m + AM-Gly) levels, in addition to plasma epinephrine (E) and norepinephrine (NE) levels, in bilateral adrenal veins of one patient. Although plasma E and NE levels decreased markedly after surgery in these patients, changes in plasma AM appeared to be confined to the normal range. There were no obvious differences in plasma AM-T, AM-m, or AM-Gly levels in adrenal veins between healthy tissue and tumor sides. Furthermore, plasma AM-T, AM-m, or AM-Gly levels in adrenal veins were comparable with those in the infrarenal inferior vena cavae (IVC) or the suprarenal IVC. In contrast, plasma E and NE levels increased in the adrenal vein of the healthy side and increased further in the adrenal vein of the tumor side compared with those in the infrarenal IVC. These results suggest that the origin of plasma E and NE is the adrenal gland and that elevated plasma levels of E and NE in pheochromocytoma are due to excessive production of E and NE in the adrenal gland of the tumor side. In contrast, it is suggested that neither plasma AM levels in the adrenal vein of the healthy side nor those of the tumor side contribute to the systemic levels of plasma AM. The present results appear to be consistent with the hypothesis that the source of circulating AM is systemic vasculature.
authors.affiliation: Department of Hypertension and Cardiorenal Medicine, Dokkyo University School of Medicine, Mibu, Tochigi 321-0293, Japan. j-minami@dokkyomed.ac.jp
authors.forename: Junichi
authors.initials: J
authors.lastname: Minami
authors.forename: Toshio
authors.initials: T
authors.lastname: Nishikimi
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Todoroki
authors.forename: Chieko
authors.initials: C
authors.lastname: Kashiwakura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yagi
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Ono
authors.forename: Shigeo
authors.initials: S
authors.lastname: Horinaka
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ishimitsu
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsuoka
mesh_terms: D000293:Adolescent; D053607:Adrenomedullin; D015740:Calcitonin Gene-Related Peptide / Q000097:blood* / Q000235:genetics; D004837:Epinephrine / Q000097:blood; D005260:Female; D006801:Humans; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010455:Peptides / Q000097:blood* / Q000235:genetics; D010673:Pheochromocytoma / Q000097:blood* / Q000601:surgery; D011863:Radioimmunoassay
chemical_list: D010455:Peptides; D053607:Adrenomedullin; D015740:Calcitonin Gene-Related Peptide; D009638:Norepinephrine; D004837:Epinephrine