Enhancement of aromatase activity by D-aspartic acid in the ovary of the lizard Podarcis s. sicula

Reproduction. 2001 May;121(5):803-8. doi: 10.1530/rep.0.1210803.


The present study investigated the role of D-aspartic acid (D-Asp) in ovarian steroidogenesis and its effect on aromatase activity in the lizard, Podarcis s. sicula. It was determined that D-Asp concentrations vary significantly during phases of the reproductive cycle: they vary inversely with testosterone concentrations and directly with oestradiol concentrations in the ovary and plasma. Experimental treatment showed that administration of D-Asp induces a decrease in testosterone and an increase in oestradiol, and that treatment with other amino acids (L-Asp, D-Glu and D-Ala) instead of D-Asp has no effects. Experiments in vitro confirmed these results. Furthermore, these experiments showed an increase in aromatase activity, as the addition of D-Asp either to fresh ovarian tissue homogenate or to acetonic powder of ovarian follicles induced a significant increase in the conversion of testosterone to oestradiol. Aromatase activity is four times greater in the presence of D-Asp than in its absence. However, almost equivalent values of the two K(m) values (both approximately 25 nmol l(-1)) indicate that aromatase has the same catalytic properties in both cases.

MeSH terms

  • Animals
  • Aromatase / metabolism*
  • Aspartic Acid / analysis
  • Aspartic Acid / metabolism
  • Aspartic Acid / pharmacology*
  • Estradiol / analysis
  • Estradiol / blood
  • Female
  • Kinetics
  • Lizards / metabolism*
  • Ovary / chemistry
  • Ovary / drug effects*
  • Ovary / enzymology*
  • Testosterone / analysis
  • Testosterone / blood


  • Aspartic Acid
  • Testosterone
  • Estradiol
  • Aromatase