Reproductive implication of D-aspartic acid in human pre-ovulatory follicular fluid.
BACKGROUND
In the present study, we report that D-aspartic acid (D-Asp) occurs in human ovarian follicular fluid and that a relationship may exist between the concentration of this amino acid and oocyte quality.


METHODS
Samples of pre-ovulatory follicle fluid were obtained from 20 patients undergoing an IVF programme. The concentration of D-Asp was measured by using specific high-performance liquid chromatography (HPLC) combined with a d-aspartate oxidase.


RESULTS
D-Asp occurs in human follicular fluid at a mean concentration of 14.98 +/- 4.51 nmol/ml. A significant difference in the content of this amino acid in the follicular fluid in relation to patient's age exists. In younger women aged 22-34 years (group A), D-Asp was found at a concentration of 19.11 +/- 1.91 nmol/ml, whereas in patients aged 35-40 years (group B), it decreased to 10.86 +/- 1.22 nmol/ml (P < 0.01). In addition, this amino acid was linked to oocyte quality; a relationship exists between D-Asp follicular concentration and the percentage of good quality metaphase II oocytes (P < 0.01), as well as the fertilization rate.


CONCLUSIONS
In human follicular fluid, D-Asp is present at a relatively higher concentration in younger women than in older patients and there appears to be a relationship between the concentration of d-Asp and fertility outcome parameters. These findings suggest that follicular D-Asp concentration may be considered as an alternative or additional biochemical marker for oocyte quality in patients undergoing IVF programmes.
D'Aniello
G
G
Department of Obstetrics, Gynecology and Physiopathology of Human Reproduction, Hospital S. Luca, 84078 Vallo della Lucania SA, Italy. gdaniello@hotmail.com
Grieco
N
N
Di Filippo
M A
MA
Cappiello
F
F
Topo
E
E
D'Aniello
E
E
Ronsini
S
S
D000328:Adult; D000367:Age Factors; D015415:Biomarkers / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D026603:D-Aspartic Acid / Q000302:isolation & purification / Q000378:metabolism*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D015571:Follicular Fluid / Q000378:metabolism*; D005498:Follicular Phase / Q000378:metabolism*; D006801:Humans; D009865:Oocytes / Q000378:metabolism*
D015415:Biomarkers; D026603:D-Aspartic Acid