Premium
In vitro secretion of FSH by cultured clinically nonfunctioning and gonadotroph pituitary adenomas is directly correlated with locally produced levels of activin A
Author(s) -
Wessels H. T.,
Hofland L. J.,
Van Der Wal R.,
Van Gastel L.,
Van Koetsveld P. M.,
De Herder W. W.,
De Jong F. H.
Publication year - 2001
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1046/j.1365-2265.2001.01194.x
Subject(s) - follistatin , endocrinology , medicine , pituitary adenoma , pituitary gland , adenoma , gonadotropin , biology , secretion , hormone
OBJECTIVE Expression of mRNAs encoding activin and its antagonists inhibin and follistatin has been described in human pituitary adenomas, including clinically nonfunctioning adenomas (NFAs) and gonadotroph adenomas (Gn‐omas). Since many of the NFAs and Gn‐omas secrete FSH in vitro , we hypothesized that locally produced activin may stimulate secretion of FSH in these pituitary adenomas. PATIENTS and METHODS Pituitary adenoma tissue was obtained from 38 patients diagnosed preoperatively as having NFAs ( n = 17), Gn‐omas ( n = 5), prolactinomas ( n = 6) or growth hormone (GH)‐producing adenomas ( n = 10). Actual protein levels of activin, inhibin, follistatin, FSH and LH were measured in media of these 38 cultured pituitary adenomas. In addition, we investigated correlations between concentrations of these growth factors and hormones in NFAs and Gn‐omas. RESULTS Gn‐omas were found to secrete significantly more activin A in their culture medium than PRL‐ and GH‐producing adenomas ( P < 0·05). Inhibin A and inhibin B protein levels in culture media were very low. A positive correlation between levels of activin A and FSH ( r = 0·56, P < 0·005) was found, while no correlation between activin A and LH could be detected. Furthermore, levels of follistatin were positively correlated with activin A levels ( r = 0·73, P < 0·0005). Comparison of the activin A:follistatin ratio with the measured FSH protein levels showed an even stronger relationship ( r = 0·79, P < 0·0005). CONCLUSIONS It is concluded that levels of activin A, follistatin and FSH in media of cultured nonfunctioning adenomas and gonadotroph adenomas are positively correlated. This suggests that these adenomas secrete FSH in response to the relatively high locally produced levels of activin A.