Thiobarbituric acid reactive substances (TBARs) in follicular fluid – relation with oocyte degeneration

Abstract

OBJECTIVE: Follicular fluid is comprised of a series of proteins, ions, growth factors, and metabolites which participate in oocyte maturation during the FSH-responsive antral stage. Exogenous FSH may allow development of incompetent oocytes, and thus generate follicular fluid with altered levels of metabolites. We wished to verify levels of TBARs – indicative of lipid peroxidation – in follicular fluid of women undergoing controlled ovarian stimulation.DESIGN: Prospective study.MATERIALS AND METHODS: Follicular fluid was retrieved following oocyte recovery, and separated for analysis. TBARs were measured using a spectrophotometric assay. In order to verify if TBARs were different in follicles with oocytes, 73 follicles were included. Subsequently, correlations were verified between TBARs levels and oocyte maturity and number of degenerated oocytes, according to cycle outcome.RESULTS: Although cluster analysis demonstrated two separate clusters: one with only follicles presenting oocytes and lower TBARs levels and the other with only follicles not presenting oocytes and higher TBARs levels, there was no difference between TBARs levels in oocyte or non-oocyte-containing follicles. Interestingly, TBARs levels were correlated with the number of degenerated oocytes in negative outcome cycles (r=0.549), but not in cycles leading to pregnancy (r=0.034).CONCLUSIONS: Although TBARs seem to be lower in follicles containing oocytes, this has yet to be demonstrated. However, the association between the presence degenerated oocytes and TBARs levels may be indicative that oxidative stress plays a role in decreasing oocyte quality. OBJECTIVE: Follicular fluid is comprised of a series of proteins, ions, growth factors, and metabolites which participate in oocyte maturation during the FSH-responsive antral stage. Exogenous FSH may allow development of incompetent oocytes, and thus generate follicular fluid with altered levels of metabolites. We wished to verify levels of TBARs – indicative of lipid peroxidation – in follicular fluid of women undergoing controlled ovarian stimulation. DESIGN: Prospective study. MATERIALS AND METHODS: Follicular fluid was retrieved following oocyte recovery, and separated for analysis. TBARs were measured using a spectrophotometric assay. In order to verify if TBARs were different in follicles with oocytes, 73 follicles were included. Subsequently, correlations were verified between TBARs levels and oocyte maturity and number of degenerated oocytes, according to cycle outcome. RESULTS: Although cluster analysis demonstrated two separate clusters: one with only follicles presenting oocytes and lower TBARs levels and the other with only follicles not presenting oocytes and higher TBARs levels, there was no difference between TBARs levels in oocyte or non-oocyte-containing follicles. Interestingly, TBARs levels were correlated with the number of degenerated oocytes in negative outcome cycles (r=0.549), but not in cycles leading to pregnancy (r=0.034). CONCLUSIONS: Although TBARs seem to be lower in follicles containing oocytes, this has yet to be demonstrated. However, the association between the presence degenerated oocytes and TBARs levels may be indicative that oxidative stress plays a role in decreasing oocyte quality.