Pulsatile thyrotropin and prolactin secretion in a patient with a mixed thyrotropin- and prolactin-secreting pituitary adenoma.
The circadian and pulsatile thyrotropin (TSH) and prolactin (PRL) release was investigated in a patient with slight hyperthyroidism due to a mixed TSH- and PRL-secreting pituitary adenoma. Blood was withdrawn every 10 min for 24 h (before and after medical treatment); pulse characteristics were analyzed by Desade and Cluster programs (values as mean +/- SD). The inappropriately high mean 24-h TSH concentration of 3.55 +/- 0.31 mU/l was associated with a higher mean 24-h TSH pulse amplitude but unaltered mean 24-h TSH pulse frequency relative to healthy controls. The nocturnal TSH surge (absolute surge 0.5 mU/l, relative surge 16%) was low, related to a loss of the usual nocturnal increase of TSH pulse amplitude and TSH pulse frequency. Chronic treatment with octreotide resulted in a modest clinical and biochemical improvement of the hyperthyroid state; addition of bromocriptine at a later stage had no further beneficial effect. At the end of the follow-up period the mean 24-h TSH paradoxically had increased to 5.33 +/- 0.81 mU/l. The nocturnal TSH surge also increased (absolute surge 1.9 mU/l, relative surge 42%), but circadian changes in TSH pulsatility remained absent. In the untreated period the increased mean 24-h PRL concentration of 234 +/- 24 micrograms/l was associated with an increased mean 24-h PRL amplitude, whereas the 24-h PRL pulse frequency (N = 4) was lower relative to controls. No circadian PRL rhythm was present. After octreotide and bromocriptine treatment the mean 24-h PRL concentration and mean 24-h PRL pulse amplitude were unchanged, but a clear nocturnal increase of PRL now was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Adriaanse
R
R
Department of Endocrinology, Academic Medical Center, University of Amsterdam, The Netherlands.
Brabant
G
G
Endert
E
E
Bemelman
F J
FJ
Wiersinga
W M
WM
D000236:Adenoma / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D000328:Adult; D001971:Bromocriptine / Q000627:therapeutic use; D002940:Circadian Rhythm; D016000:Cluster Analysis; D005500:Follow-Up Studies; D006801:Humans; D006980:Hyperthyroidism / Q000209:etiology; D008297:Male; D015282:Octreotide / Q000627:therapeutic use; D010911:Pituitary Neoplasms / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D015175:Prolactinoma / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D011673:Pulsatile Flow; D013972:Thyrotropin / Q000378:metabolism*; D014792:Visual Acuity
D001971:Bromocriptine; D011388:Prolactin; D013972:Thyrotropin; D015282:Octreotide