Euprolactinemic Galactorrhea. Response of bioassayable prolactin to thyrotropin-releasing hormone.
OBJECTIVE
To define whether the pathophysiology of euprolactinemic galactorrhea (EuG) involves hyperresponsiveness to thyrotropin-releasing hormone (TRH).


METHODS
Basal and TRH-induced prolactin (PRL) patterns were examined in women with EuG (n = 7) and compared to those in controls (n = 10) with normal menstrual cycles. PRL activity was measured by radioimmunoassay (RIA) and Nb2 lymphoma cell bioassay (BA). The response of BA-PRL, RIA-PRL, the BA/RIA-PRL ratio and lactogenic activity to TRH given intravenously were studied.


RESULTS
The response of RIA-PRL, BA-PRL, lactogenic activity (representing both PRL and growth hormone in the Nb2 lymphoma cell bioassay) and BA/RIA-PRL ratio were not significantly different in EuG as compared to controls. In both groups the combined BA/ RIA-PRL ratio increased at 15 (P = .006), 30 (P = .011), and 90 minutes (P = .022) after TRH injection as compared to zero time. The level of serum progesterone at the time of TRH stimulation did not affect the response of any parameter studied.


CONCLUSIONS
The response of BA-PRL, RIA-PRL and the BA/RIA-PRL ratio to TRH was not significantly different in EuG as compared to controls. The mechanism of EuG did not involve hyperresponsiveness of BA-PRL, RIA-PRL, the BA/RIA-PRL ratio or lactogenic activity to TRH.
Ataya
K M
KM
Department of Obstetrics and Gynecology, Case Western Reserve University, Cleveland, OH 44109-1998, USA.
Subramanian
M G
MG
Lawson
D M
DM
Gala
R R
RR
D000328:Adult; D005260:Female; D005687:Galactorrhea / Q000097:blood*; D006801:Humans; D007275:Injections, Intravenous; D011388:Prolactin / Q000097:blood*; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage*; D013997:Time Factors
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin