PROBLEM: Using an IVF model, the goal of the study was to investigate the r
elationship between follicular fluid (ff) NO and IL-1 beta levels, as well
as their correlation with fertilization of mature oocytes and embryo cleava
METHOD OF STUDY: Follicular fluid was collected from 17 patients at the tim
e of transvaginal oocyte retrieval following controlled ovarian stimulation
. Oocytes harvested from these follicles were followed through fertilizatio
n and embryo cleavage. The NO metabolites nitrate/nitrite (NO3/NO2) were me
asured using the Griess reaction as an indirect assessment of NO activity.
IL-1 beta was measured using a high sensitivity ELISA system (Amersham, UK)
. The Student's t-test was utilized for unpaired data with the means consid
ered significantly different when P less than or equal to 0.05.
RESULTS: Follicular fluid NO3/NO2 levels were significantly lower in follic
les containing mature oocytes that fertilized (n = 30; 9.7 +/- 1.0 muM), ve
rsus those that did not fertilize (n = 23; 15.4 +/- 2.4 muM; P < 0.05). Fol
licles that contained oocytes that fertilized and went on to divide beyond
the 6 cell stage had significantly lower ff levels of NO3/NO2 (n = 18; 7.5
+/- 0.9 <mu>M), as compared to ff that contained oocytes that did not ferti
lize or failed to develop beyond the 5 cell stage (n = 35; 14.6 +/- 1.7 muM
; P < 0.01). No correlation was found between ff NO3/NO2 levels (n = 28; 13
.8 +/- 2.0 <mu>M) and ff IL-1 beta levels (n = 28; 0.5 +/- 0.08 pg/mL). An
analysis of ff IL-IP levels in relation to fertilization and embryo cleavag
e rates revealed no correlation.
CONCLUSIONS: Lower ff NO3/NO2 levels at the time of oocyte retrieval are as
sociated with adequate fertilization and embryo cleavage rates. In our IVF
model, no correlation was found between ff IL-1 beta levels and ff NO3/NO2,
fertilization, or embryo cleavage rates.