Is the D-Aspartic acid implied in the control of gonads' steroidogenesis?

In female Podarcis s. sicula, D-Aspartic acid (D-Asp) is present in the ovary and significantly increases in females engaged in vitellogenesis. It, moreover, induces, either in vivo or in vitro, a decrease of testosterone level and an increase of 17beta-estradiol level, both in ovary and plasma. These findings let to assign an interesting regulatory role to D-Asp in lower vertebrate gonad's control. D-Asp, in fact, seems to act by inducing an enhancement of ovarian aromatase activity and, therefore, favours the conversion of testosterone into 17beta-estradiol. During reproduction, female lizard liver synthesised paramount amounts of vitellogenin, a process induced by ovarian 17beta-estradiol. Therefore, D-Asp helps to sustain an additional 17beta-estradiol availability, useful to lizard reproductive physiology.D-Asp, finally, is proposed as a new regulatory agent of steroidogenesis in vertebrates.