[Endothelin-1 receptors of the normal adrenal gland and adrenal tumors in human].
Endothelin-1 (ET-1) receptors of normal adrenal gland (ADR, 6 cases), aldosterone-producing adenoma (APA, 5 cases), idiopathic hyperaldosteronism (IHA, 4 cases) and pheochromocytoma (PHE, 6 cases) in human were measured by radioligand binding assay (RBA) of receptors. Binding studies using 125I-ET-1 as a radio ligand showed the presence of a single class of high-affinity binding sites for ET-1 in all of the above tissues. The values of dissociation constant (Kd) of ET-1 for its receptor were similar in ADR, APA and IHA (28.3 +/- 2.5, 27.9 +/- 6.1, 27.7 +/- 1.9 pmol/L, respectively), but the maximal binding capacity (Bmax) of ET receptor tended to be lower in APA tissue (107.2 +/- 13.2 fmol/mg protein) in comparison with ADR (P < 0.01) and IHA (P < 0.05, 274.9 +/- 40.8, 247.0 +/- 19.8 fmol/mg protein, respectively). Both the Kd (50.8 +/- 5.1 pmol/L) and Bmax (675.3 +/- 93.7 fmol/mg protein) in PHE were higher than those in ADR (P < 0.01), APA (P < 0.01) or IHA (P < 0.05 for Kd, P < 0.01 for Bmax). Our data may suggest that there is the down-regulation for ET-1 receptor in APA and support the concept of an important role of ET-1 in the paracrine-autocrine regulation of aldosterone and catecholamine secretion in the adrenal and adrenal tumors.
Tang
X
X
Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing.
Zeng
Z
Z
Zhang
R
R
D000236:Adenoma / Q000378:metabolism; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000378:metabolism*; D000311:Adrenal Glands / Q000378:metabolism*; D000328:Adult; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000378:metabolism; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin / Q000378:metabolism*
D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin