H. Abdelrazik

L-Carnitine decreases DNA damage and improves the in vitro blastocyst development rate in mouse embryos

OBJECTIVE To optimize the L-carnitine (LC) concentration as a supplement in embryo culture medium and to investigate the effect of LC on developing embryos. DESIGN Experimental study. SETTING Reproductive research center at a tertiary hospital. INTERVENTION(S) To optimize the LC concentration, 420 mouse embryos were divided into seven groups and incubated with different LC concentrations (0, 0.3, 0.6, 1.2, 2.5, 5.0, and 10 mg/mL). To investigate the effect of LC on the developing embryos, 500 mouse embryos were divided into three groups and incubated with either actinomycin-D (AD; 0.005 microg/mL), hydrogen peroxide (H(2)O(2); 500 micromol/L), or tumor necrosis factor alpha (TNF-alpha; 500 ng) with and without LC 0.3 or 0.6 mg/mL. Blastocyst development rate (%BDR) and DNA damage were examined for all groups. MAIN OUTCOME MEASURE(S) Effect of LC on embryogenesis. RESULT(S) Significant improvement in %BDR was seen at LC 0.3 mg/mL compared with the control (p = 0.006). L-Carnitine at 0.3 and 0.6 mg/mL significantly reduced the blocking effect of AD, H(2)O(2), and TNF-alpha and significantly decreased the level of DNA damage. CONCLUSION(S) Embryo culture medium supplementation with LC may offer a novel and a cost-effective technique to improve the embryogenesis of cultured embryos. This may be beneficial in improving IVF outcomes.

L-carnitine supplementation reduces oocyte cytoskeleton damage and embryo apoptosis induced by incubation in peritoneal fluid from patients with endometriosis

OBJECTIVE To investigate the protective effect of L-carnitine (LC) against deleterious substances present in the peritoneal fluid (PF) of patients with endometriosis, which may affect the oocyte cytoskeleton and embryogenesis. DESIGN Experimental study. SETTING Research embryology laboratory at an academic hospital. PATIENT(S) Frozen metaphase II mouse oocytes and embryos. INTERVENTION(S) One hundred metaphase II mouse oocytes were divided into five groups and incubated: PF from endometriosis patients; PF from endometriosis patients + LC; PF from tubal ligation patients (patient control); LC only; and human tubal fluid (HTF) alone. A total of 180 eight-cell mouse embryos were divided into: endometriosis only; tubal ligation only; endometriosis + LC; LC alone; and HTF alone. MAIN OUTCOME MEASURE(S) Protective effect of LC on oocytes and embryos. RESULT(S) Incubation of the oocytes and the embryos with PF from patients with endometriosis statistically significantly damaged the oocyte microtubules and chromosomes and increased embryo apoptosis compared with controls. Incubation with LC (0.6 mg/mL) statistically significantly improved microtubule and chromosome structure and decreased the level of embryo apoptosis. CONCLUSION(S) We propose the use of LC as a supplement in patients with endometriosis, a novel approach that may help improve in vitro fertilization outcome in these patients.

Evaluation of post-thaw DNA integrity of mouse blastocysts after ultrarapid and slow freezing

OBJECTIVE To evaluate the effect of vitrification and two other methods of slow cryopreservation on DNA integrity in expanded and nonexpanded blastocysts. DESIGN Prospective in vitro study. SETTING Tertiary care academic hospital. INTERVENTION(S) 1) Twenty-two expanded blastocysts (EB) and 17 nonexpanded blastocysts (NEB) vitrified in cryotips; 2) 15 EB and 16 NEB by slow freezing using propanediol; 3) 11 EB and 16 NEB by slow cryopreservation using glycerol; and 4) 14 EB and 13 NEB as fresh control samples. MAIN OUTCOME MEASURE(S) DNA fragmentation by TUNEL and confocal imaging. RESULT(S) Blastocysts slowly cryopreserved with glycerol showed DNA integrity of 94.76 +/- 4.70% and 90.87 +/- 6.16% for NEB and EB, respectively. Propanediol cryopreservation showed values of 72.63 +/- 13.44% and 56.19 +/- 25.49% and vitrification 84.36 +/- 8.7%6 and 77.61 +/- 16.65%, respectively, for the same groups. The NEB showed less DNA fragmentation than EB in all cryopreservation techniques, but this was significant only with slow freezing using propanediol. CONCLUSION(S) All cryopreservation techniques induce DNA damage to blastocysts. Damage is maximal with propanediol and minimal with slow freezing using glycerol. The more expanded the blastocyst, the greater is the susceptibility to DNA damage during cryopreservation.