[Glycoprotein hormone alpha-subunit secretion in non-functioning pituitary adenomas].
The aim of the present study was to investigate the prevalence of elevated free glycoprotein hormone alpha-subunit in different pituitary adenomas, to establish the diagnostic value of the basal and stimulated free alpha-subunit secretion in non-functioning adenomas. Serum basal levels of alpha-subunit were increased in 1 of 22 untreated, in 1 of 16 operated patients with non-functioning adenoma, in 6 of 28 untreated, in 1 of 7 operated patients with acromegaly, in 0 of 5 untreated prolactinomas and in 0 of 1 untreated gonadotrop adenoma. Overall free alpha-subunit levels were increased in 9 of 79 cases (11.4%). In 6 of 9 patients with untreated non-functioning adenoma thyrotrop hormone releasing hormone caused an abnormal--paradox--elevation of serum alpha-subunit. These data indicate that measurement of basal and stimulated alpha-subunit is of relatively poor value in the diagnosis of non-functioning pituitary adenomas. The transsphenoidal surgery did not resulted in a change of alpha-subunit secretion neither in patients with non-functioning adenoma nor with acromegaly. The present data confirm the view that non-functioning pituitary adenomas are not homogeneous since this subset of tumors includes adenomas that either do not secrete measurable amounts of free alpha-subunit or produce normal or supranormal amounts of subunits as consequence of still undefined biosynthetic abnormalities.
Góth
M
M
Haynal Imre Egészségtudományi Egyetem, I. Belgyógyászati Klinika, Budapest.
Szabolcs
I
I
Czirják
S
S
Hubina
E
E
Kovács
L
L
Dohán
O
O
Szilágyi
G
G
D000236:Adenoma / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D005260:Female; D015292:Glycoprotein Hormones, alpha Subunit / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D015175:Prolactinoma / Q000378:metabolism* / Q000473:pathology / Q000601:surgery
D015292:Glycoprotein Hormones, alpha Subunit