INSULIN-LIKE GROWTH-FACTOR-1 (IGF-1) IN MULTINODULAR GOITERS - A POSSIBLE PATHOGENETIC FACTOR

In order to support previous in vitro studies which had stressed a pos sible autocrine role for Insulin-like Growth Factor 1 (IGF-1) in thyro id growth regulation, we have investigated the presence of IGF-1, as d etected by means of radioimmuno assay and of immunocytochemistry, in t hyrocytes from normal thyroid and from multinodular goiter. Our study revealed that IGF-1 is detectable in thyroid cells from multinodular g oiter and, to a lesser extent, from normal thyroid. Both techniques us ed in this study demonstrated that thyrocytes are the site of accumula tion of IGF-1 and that stromal cells contain lower amounts of this gro wth factor. The findings of the Present study seem to suggest that thy rocytes could produce IGF-1 in vivo. This feature gives further suppor t to the hypothesis that IGF-1 may regulate thyroid growth and therefo re it might be involved in the pathogenesis of multinodular goiter.