Oxidative stress markers in preovulatory follicular fluid in humans

Intensified peroxidation in the Graafian follicle may be a factor compromis ing the normal development of the oocyte. The aim of this study was to meas ure concentrations of three oxidative stress markers: conjugated dienes, li pid hydroperoxides and thiobarbituric acid-reactive substances, in preovula tory follicular fluids and sera of 145 women attending an in-vitro fertiliz ation programme, and to correlate these concentrations with pregnancy outco me. Determinations were conducted either with or without an antioxidant (10 mu M butylated hydroxytoluene) and an iron chelate (10 mu M deferoxamine m esylate) to examine peroxidation associated with the methods used. Concentr ations of conjugated dienes, lipid hydroperoxides and thiobarbituric acid-r eactive substances in follicular fluid were all significantly lower than th ose in serum, both in the presence or absence of the antioxidant and iron c helate. These concentrations did not correlate with pregnancy outcome. In c onclusion, the intensity of peroxidation in the Graafian follicle is much l ower than that in serum. This gradient is the result of the lower rate of i nitiation of peroxidation in the follicular fluid, suggestive of the presen ce of efficient antioxidant defence systems in the direct milieu of the ooc yte before ovulation. The concentrations of investigated oxidative stress m arkers in follicular fluid do not reflect the reproductive potential of ooc ytes.