Immunoreactive endothelin in Taiwanese thyroid cystic fluid.
Endothelin-1 is a major vasoconstrictor peptide, first found in endothelial cells and later in many other tissues, including the thyroid gland. It is well known that endothelins can act as autocrine and/or paracrine regulators of thyroid homeostasis and growth. Previously we have demonstrated that immunoreactive endothelins (IR-ET) are present in various human body fluids, and IR-ET has also been detected in pathologic breast and thyroid cystic fluids. In this study, the IR-ET in Taiwanese thyroid cystic fluid was measured by radioimmunoassay and characterized by chromatography. Human thyroid cystic fluid was obtained by fine needle aspiration, was centrifuged, and the supernatant was stored at -20 degrees C until IR-ET assay. IR-ET has been detected in 25 of 33 samples of thyroid cystic fluid [25 cases, 4.11 +/- 0.31 fmol/mL (mean +/- standard error of the mean); other eight cases, undetectable]. Gel permeation chromatography of the extract of pooled cystic fluid showed only one major peak at the elution position of human endothelin-1 standard. No difference in cystic IR-ET levels was found in our patients with cystic nodules in relation to differences in thyroid function. It is probable that endothelin-1 is produced by the epithelial cells lining the thyroid cysts, and the increased levels of IR-ET in cystic fluid found in our patients could either be secondary to cystic nodule development or have a role in goiter formation.
Lam
Hing-Chung
HC
Division of Medical Research, Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China. hclam@isca.vghks.gov.tw
Lee
Jenn-Kuen
JK
Lu
Chih-Chen
CC
Chu
Chih-Hsun
CH
Sun
Chun-Chin
CC
Chuang
Ming-Ju
MJ
Wang
Mei-Chun
MC
D044466:Asian People; D002850:Chromatography, Gel; D020420:Cyst Fluid / Q000737:chemistry*; D003560:Cysts / Q000737:chemistry* / Q000208:ethnology; D019332:Endothelin-1 / Q000032:analysis*; D019333:Endothelin-2 / Q000032:analysis; D019334:Endothelin-3 / Q000032:analysis; D006801:Humans; D011863:Radioimmunoassay; D013624:Taiwan; D013959:Thyroid Diseases / Q000208:ethnology / Q000378:metabolism*; D015854:Up-Regulation
D019332:Endothelin-1; D019333:Endothelin-2; D019334:Endothelin-3