MONITORING FECAL SAMPLES FOR ESTROGEN EXCRETION ACROSS THE OVARIAN CYCLE IN GOELDIS MONKEY (CALLIMICO-GOELDII)

In captive Goeldi's monkeys, estrogen concentration was determined in fecal samples collected from 4 cycling/unmated females and 4 postpartu m/mated females in order to ascertain the potential of fecal estrogen monitoring for providing basic information about reproductive status i n this endangered Amazonian monkey. Subjects were fed an omnivorous di et and first-void feces were collected in the home cage at 1-3-day int ervals for 30-50 days from the cycling females, and at 6-14-day interv als around the estimated time of the postpartum ovulation in each of t he 4 mated females. Estimates for the duration of ovarian cycles (22-2 6 days) and the timing of ovulation were based on cyclic profiles of e ither blood progesterone or urinary pregnanediol-3alpha-glucuronide. F ecal estrogen values were normalized using these plasma or urinary pro files. HPLC analysis of estrogen from postpartum fecal samples demonst rated the presence of unconjugated estrone and estradiol-17beta (''unc onjugated estrogen''). Unconjugated estrogen was extracted and its fec al concentration estimated via EIA. The correlation (r) between plasma estrone conjugates and fecal unconjugated estrogen across nonconcepti on ovarian cycles was 0.65 and measurement of the latter generated cyc lic profiles. A range of 4-36-ng unconjugated estrogen g-1 feces was i dentified for follicular phases of nonconception cycles. Fecal unconju gated estrogen first exceeded the concentration range of the follicula r phase 2-5 days after ovulation; the range was 49-402 ng g-1 feces in samples collected during the remainder of these nonconception luteal phases. Luteal phase concentrations were on average 10-fold higher tha n follicular phase concentrations. Each of the 4 mated females conceiv ed at its postpartum ovulation; concentrations of fecal unconjugated e strogen excreted by 3 of these females demonstrated a marked postovula tory increase. This study demonstrates that fecal unconjugated estroge n can be applied to monitor ovarian cyclicity in Goeldi's monkey. (C) 1994 Wiley-Liss, Inc.