Production of pyruvate by isolated mouse cumulus cells.
Cumulus cells were isolated by hyaluronidase treatment of whole cumulus masses from superovulated, non-mated mice. The cells, in groups of approximately 200, were incubated for up to 4 h in 50 nl medium M2 at 37 degrees C, and serial 3-nl samples assayed for pyruvate using an ultramicrofluorescence technique. With 5.55 mM glucose, 23.3 mM lactate, or a mixture of the two substrates, the cumulus cells formed pyruvate at rates of 10.2, 9.6, and 8.9 fmol/cell/h, respectively. The concentrations of glucose, pyruvate, and lactate, as measured in 3-nl aliquots of rabbit oviduct fluid were 1.5 mM, 0.3 mM, and 3.7 mM, respectively. When incubated with 1 mM glucose and 3 mM lactate, mouse cumulus cells formed 7.5 fmol pyruvate/cell/h. The mean number of cumulus cells per ovum within a cumulus mass was 2,060. Intact cumulus masses from mated and non-mated superovulated mice, incubated with 1 mM glucose and 3 mM lactate, formed 22.6 and 23.3 pmol pyruvate/ovum/h, respectively. The results suggest that pyruvate production by cumulus cells may be important in supporting the nutrition of unfertilized and fertilized ova, and of spermatozoa, within the oviduct lumen.
D000818:Animals; D004734:Energy Metabolism; D005187:Fallopian Tubes / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D051379:Mice; D009865:Oocytes / Q000378:metabolism*; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism*
D007773:Lactates; D011773:Pyruvates; D005947:Glucose