endothelin-1 and Goiter--Nodular

Endothelin ET-1 plays an important, however not entirely identified role in physiology and pathology of thyroid gland. The aim of the study was to determine if in patients with non-toxic nodular goiter there is relationship between size of goiter and ET-1 concentration in plasma of peripheral venous blood and plasma of venous blood taken from thyroid vein in patients undergoing strumectomy. The study included 30 patients with non-toxic nodular goiter (29 women and 1 man, mean age 48 year) and 15 healthy persons of control group. In all ET-1 concentration in plasma of venous peripheral blood and T3, T4, TSH serum concentration were estimated using radioimmunologic methods, as well as size of thyroid gland were evaluated in ultrasonography. Patients with nodular goiter underwent strumectomy. During the operation, before strumectomy, blood from thyroid vein was sampled to estimate plasma ET-1 concentration. Patients were divided into two groups: with adenomatous goiter (14 patients) and colloid goiter (16 patients). The goiter size was similar in each group. In all of the groups there was no relationship between goiter size and ET-1 concentration in plasma of peripheral and thyroid vein. Lack of correlation between ET-1 concentration in plasma and goiter size does not exclude possible ET-1 role in goitrogenesis, it suggests that ET-1 may play a role in control of thyroid gland trophic regulation and vascularity as paracrine or autocrine factor. Significantly higher concentration of ET-1 in plasma of thyroid vein in comparison to plasma of peripheral venous blood and positive correlation between ET-1 concentration in thyroid and peripheral plasma were found in both studied groups of patients with goiter and this may speak for increased ET-1 production within the goiter.

Topics: Adult; Case-Control Studies; Endothelin-1; Female; Goiter, Nodular; Humans; Male; Middle Aged; Poland; Radioimmunoprecipitation Assay; Statistics, Nonparametric; Thyrotropin; Thyroxine; Triiodothyronine; Ultrasonography

Since the isolation of endothelin-1 (ET-1) in 1988, there has been tremendous interest in the pathophysiological roles of ET-1 as a vasoconstrictive and mitogenic peptide. Whereas ET-1 is mainly released by vascular endothelial cells, it also proved to be produced by various tissues including the thyroid. Because of its mitogenic properties in malignancy and its role as an inflammatory modulator, ET-1 could be involved in thyroid carcinogenesis and thyroiditis.. Studies were performed in human thyroid samples obtained at the time of surgery from 39 men and women aged 15-72 years. Thyroid samples were classified in four groups according to conventional histology: normal thyroid (n = 7) papillary thyroid carcinoma (n = 12), Hashimoto's thyroiditis (n = 9) and benign nontoxic nodular goitres (n = 11). Immunohistochemistry and real-time quantitative polymerase chain reaction were used to determine the expression of ET-1 and its receptors (ETAR and ETBR).. ET-1 and ETAR mRNA levels were, respectively, 3.8 +/- 1.3 and 4.1 +/- 1.5 times greater (P < 0.001) in papillary thyroid carcinoma than in normal thyroid. Expression of ETBR was unaltered. In Hashimoto's thyroiditis, ET-1 and ETAR were also overexpressed (P < 0.005). Furthermore, immunohistochemistry demonstrated a greater percentage of ET-1-positive follicular cells in these conditions (P < 0.001). In nodular goitres, the expression was increased by 1.7 +/- 0.7 times (P < 0.05) but expression of receptors remained unchanged.. ET-1 and ETAR overexpression observed in thyroid carcinoma suggest a mitogenic role of ET-1 that theoretically could be countered by ETAR antagonists. ET-1 and ETAR overexpression in thyroiditis supports a role of ET-1 in the inflammatory process.

Topics: Adolescent; Adult; Aged; Carcinoma, Papillary; Endothelin-1; Female; Goiter, Nodular; Humans; Immunohistochemistry; Male; Middle Aged; Receptors, Endothelin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thyroid Neoplasms; Thyroiditis, Autoimmune