Exposure to FSH before formation of the antral-like cavity had a positive effect on follicle survival and oocyte robustness.

No abstract

The fact that genetic effects were observed in irradiated animals suggests that these could also occur in humans. The probability of such events remains low compared with the 'spontaneous' risks of genetic effects.

Metabolic markers are potentially valuable for assessment of follicle development in vitro. Carbohydrate metabolism of murine preantral follicles grown to maturity over 13 days in vitro has been measured, and metabolism of resulting oocyte-cumulus complexes (OCCs) and denuded oocytes has been compared with in vivo ovulated control counterparts. Spent follicle culture media were analysed for glucose, lactate and pyruvate concentrations. During follicle in vitro growth, glycolysis accounted for a rise from w24 to 60% of all glucose consumed. Ovulation induction caused a significant increase in glucose uptake and lactate production by in vitrogrown follicles to 71.7G1.2 and 96.6G4.8 nmoles/day respectively. OCCs grown in vitro had significantly higher rates of glucose consumption and lactate and pyruvate production (110.1G3.5, 191.8G8.9 and 31.7G1.7 pmoles/h respectively) than in vivo ovulated controls (67.4G8.1, 113.9G17.1 and 20.2G4.0 pmoles/h respectively), but a reduced capacity for pyruvate consumption (1.13G0.06 vs 1.49G0.06 pmoles/h by in vivo ovulated oocytes). Metabolism of OCCs was affected by the quality of the original follicle. In vitro-grown oocytes had a reduced cytoplasmic volume when compared with controls (168.3G2.0 vs 199.0G3.2 proportionately respectively) but a similar rate of metabolism per unit volume. Meiotic status influenced metabolism of both OCCs and denuded oocytes. In conclusion, glucose consumption and lactate production by cultured follicles increased in tandem with developmental progression and were stimulated prior to ovulation. Additionally, the metabolic profiles of in vitro produced OCCs and the oocytes within them are affected by long-term exposure to the culture environment. Reproduction (2007) 134 415-424