Glucose and lactate in human follicular fluid: concentrations and interrelationships

The concentrations of glucose, lactate, progesterone and oestradiol have been measured in 122 follicular fluids obtained from women attending a natural cycle IVF programme. Some women received low-dose clomiphene. Fluids were recovered 28-35 h after the onset of the spontaneous LH surge. Mean follicular fluid volumes were greater for stimulated (4.46 ml) than spontaneous (3.11 ml) cycles. Mean glucose and lactate concentrations were similar in the two groups, with overall means of 3.29 mM (glucose) and 6.12 mM (lactate). Total glucose and lactate were greater in the fluids from stimulated (14.1 and 29.5 mol, respectively) than from the spontaneous cycles (11.5 and 20.2 mmol, respectively). There were negative correlations between follicular fluid volume and glucose concentration (r = -0.348) and between glucose concentration and lactate concentration (r = -0.367) but no relationship between follicular fluid volume and lactate concentration (r = 0.086). A model is presented to account for these findings in terms of the movement of pyruvate, glucose and lactate from the vascular theca into follicular fluid, and of glycolysis occurring in the granulosa cells.