Luteinizing hormone receptor disorder in endometriosis.

Luteinizing hormone (LH) receptor concentrations in ovarian follicles and corpora lutea were measured in 51 patients with histologically proven endometriosis and in 41 control patients. The LH receptor concentrations in cases of endometriosis were lower during the early (0.43 +/- 0.11 [mean +/- standard error] versus 1.31 +/- 0.27 fmol/mg protein; P less than 0.001) and late (0.48 +/- 0.10 versus 1.59 +/- 0.22 fmol/mg protein; P less than 0.001) follicular phase, and during the late luteal phase (2.62 +/- 0.55 versus 4.62 +/- 0.65 fmol/mg protein; P less than 0.05) of the cycle than in control patients. In contrast to the control patients, the LH receptor concentration during the follicular phase remained constant in endometriosis, being lower in patients with extensive or severe disease than in patients with moderate or mild disease (0.28 +/- 0.07 versus 0.61 +/- 0.21 fmol/mg protein; P less than 0.05). Endometriosis-associated infertility might be a consequence of a defect in the mechanism mediating LH action in the ovaries.