Midcycle increase of prolactin seen in normal women is absent in subjects with unexplained infertility.
OBJECTIVE
To compare the bioactive and immunoactive PRL in normal and unexplained infertility subjects.


METHODS
Prospective study.


METHODS
Department of Obstetrics and Gynecology, Wayne State University and The University of Michigan.


METHODS
Twelve normal, fertile women compared with 12 patients with unexplained infertility.


METHODS
Serum samples were obtained across the menstrual cycle and for each subject, 5 pools were prepared by combining serum aliquots from the early follicular, late follicular, midcycle, and midluteal and late luteal phases of the cycle.


METHODS
Niobium lymphoma cell bioassay and an immunoradiometric assay were used to quantitate PRL.


RESULTS
A midcycle increase in PRL was seen in controls by both assays and these levels were greater compared with other cycle stages. Comparison of midcycle PRL between groups showed differences only between bioactive PRL (34.2 +/- 8.3 versus 19.2 +/- 3.4 ng/mL [conversion factor to SI unit, 1.00]). The ratios between bioactive and immunoactive PRL were comparable. Significant correlation between bioactive and immunoactive PRL was seen for both control (r = 0.616) and unexplained infertility (r = 0.660) groups.


CONCLUSIONS
The midcycle elevations of bioactive and immunoactive PRL seen in normal women were absent in women with unexplained infertility. This alteration in PRL dynamics may be a part of subtle differences in the reproductive hormone profile of women with unexplained infertility compared with their fertile counterparts.
Subramanian
M G
MG
Department of Obstetrics and Gynecology, Wayne State University, C. S. Mott Center, Detroit, Michigan 48201, USA.
Kowalczyk
C L
CL
Leach
R E
RE
Lawson
D M
DM
Blacker
C M
CM
Ginsburg
K A
KA
Randolph
J F
JF
Diamond
M P
MP
Moghissi
K S
KS
D000328:Adult; D001681:Biological Assay; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D007247:Infertility, Female / Q000097:blood*; D008597:Menstrual Cycle / Q000097:blood* / Q000502:physiology; D010928:Placental Lactogen / Q000097:blood; D011388:Prolactin / Q000097:blood* / Q000276:immunology; D011446:Prospective Studies; D012016:Reference Values
D011388:Prolactin; D010928:Placental Lactogen