THE CONCENTRATIONS OF COLLAGEN-ASSOCIATED AMINO-ACIDS ARE HIGHER IN GNRH AGONIST-TREATED UTERINE MYOMAS

Objective: To test the hypothesis that the effects of estrogen reducti on on uterine leiomyoma regression are mediated through changes in cel l density or the extracellular matrix. Methods: Uterine myomas were ob tained from 20 women who had received randomly either the GnRH agonist leuprolide acetate depot for 3 months or placebo. The biochemical and morphologic characteristics studied included: total protein, DNA, and amino acid concentrations; histologic appearance; collagen content; a nd nuclear density. Results: The absolute and relative concentrations of hydroxylysine, hydroxyproline, glycine, and proline were significan tly greater (P < .05) in uterine myomas from patients pretreated with a GnRH agonist compared with placebo-treated controls. The GnRH agonis t was also associated with trends toward increased mean total protein, DNA, and nuclear density, but the differences did not reach statistic al significance. Conclusions: The concentrations of the amino acids co ntained in collagen were significantly greater in uterine myomas from patients treated with the GnRH agonist compared to myomas from placebo -treated controls. In addition, our observations suggest that the redu ction in uterine myoma volume associated with GnRH agonist therapy is associated with alterations in the extracellular matrix.