Altered autophosphorylation of the insulin receptor in the ovary of a woman with polycystic ovary syndrome.
OBJECTIVE
To determine whether the tyrosine autophosphorylation of the insulin receptor (IR) in the ovary of a woman with polycystic ovary syndrome (PCOS) was reduced compared to normal.


METHODS
Experimental study.


METHODS
Tertiary care medical center.


METHODS
One woman with PCOS and one healthy control, both of whom underwent a hysterectomy and bilateral salpingo-oophorectomy.


METHODS
Plasma membrane fraction of ovarian tissue was isolated, and the IR was purified and concentrated.


METHODS
Western blots of the IR, which had been incubated with and without insulin, were prepared. Colorimetric and chemiluminescent methods were used to detect the presence of the IR beta-subunit and IR tyrosine autophosphorylation, respectively.


RESULTS
The presence of the beta-subunit of the IR was identified in both ovarian samples. The degree of insulin-stimulated IR tyrosine autophosphorylation, reflected by the mean (+/-SD) relative optical density of the 95 kd band, was 4.3-fold higher in the normal ovary compared to the PCOS ovary (0.56 +/- 0.18 optical density vs. 0.13 +/- 0.10 optical density, respectively).


CONCLUSIONS
Tyrosine autophosphorylation of the IR may be decreased in the ovaries of women with PCOS, similar to the findings in other tissues. The mechanisms through which insulin acts to produce an excess in ovarian androgen production in the face of a decrease in ovarian IR autophosphorylation remain to be determined.
Moran
C
C
Department of Obstetrics and Gynecology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
Huerta
R
R
Conway-Myers
B A
BA
Hines
G A
GA
Azziz
R
R
D000328:Adult; D015153:Blotting, Western; D003124:Colorimetry; D005187:Fallopian Tubes / Q000601:surgery; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008163:Luminescent Measurements; D008875:Middle Aged; D010052:Ovariectomy; D010053:Ovary / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011085:Polycystic Ovary Syndrome / Q000378:metabolism*; D011972:Receptor, Insulin / Q000378:metabolism*
D019000:Phosphotyrosine; D011972:Receptor, Insulin