Localization of inhibin/activin subunits in normal pituitary and in pituitary adenomas.
The localization of inhibin/activin (I/A) subunits was investigated in human normal adenohypophysial cells and in 87 pituitary adenomas of different types, using immunohistochemistry. Monoclonal antibodies directed against alpha, beta A and beta B subunits of I/A were employed. In normal pituitary, alpha subunit of inhibin was detected only in FSH-positive gonadotrophs, while beta A subunit of I/A was expressed in FSH-positive gonadotrophs, GH-cells and in a few PRL-cells. beta B subunit was found in FSH-positive gonadotrophs, TSH-cells and a few LH-positive gonadotrophs. The three subunits of I/A were detected in the majority of nonfunctioning tumors, while functioning adenomas showed a significantly lower expression. This study shows that alpha, beta A and beta B subunits of I/A are expressed by specific adenohypophysial cell types and that they are characteristically present in nonfunctioning adenomas. These results suggest that inhibins and activins may play a role in the local regulation of pituitary hormonal secretion both in normal adenohypophysial cells and in pituitary adenomas.
Uccella
S
S
Department of Clinical and Biological Sciences, University of Insubria, Varese, Italy.
La Rosa
S
S
Genasetti
A
A
Capella
C
C
D028341:Activins; D000236:Adenoma / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007265:Inhibins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D014018:Tissue Distribution
D020033:Protein Isoforms; D028341:Activins; D007265:Inhibins