DETERMINATION OF OVARIAN CYCLE IN GOELDIS MONKEY (CALLIMICO-GOELDII) VIA THE MEASUREMENT OF STEROIDS AND PEPTIDES IN PLASMA AND URINE

Goeldi's monkey (Callimico goeldii) is an endangered species of New Wo rld primate. The present study provides the first description of the n on-conception ovarian cycle in this species based on circulating repro ductive steroid and peptide hormones. The data obtained were used to v alidate a non-invasive system for monitoring cyclicity based on urinar y reproductive steroid metabolites. Nine sexually mature females were studied. In three females, matched blood and urine samples were collec ted once every 2-3 days for 90-120 days; in three other females, match ed blood and urine samples were collected daily for 14-20 days for one peri-ovulatory period; and in the remaining three females, urine samp les only were collected once every 1-3 days for 40-60 days. Plasma pro gesterone, oestrone-3-conjugates and bioactive LH were measured, in ad dition to urinary pregnanediol-3 alpha-glucuronide and oestrone-3-conj ugates. The mean maximum concentration of plasma LH occurred 1-2 days before a significant rise in plasma progesterone, which was considered to occur 1 day after ovulation. On the basis of plasma progesterone t itres, the duration of the ovarian cycle was estimated as 23.9 +/- 0.4 days (n = 9), and constituted a follicular phase of 10.7 +/- 0.3 days and a luteal phase of 13.5 +/- 0.3 days. Urinary pregnanediol-3 alpha -glucuronide demonstrated a high correlation with plasma progesterone (r = 0.8), and demonstrated a significant rise at the same time as pla sma progesterone. Application of this urinary progesterone metabolite to determine whether a female was in a follicular phase (pregnanediol- 3 alpha-glucuronide < 0.20 mu g mg(-1) creatinine) or a luteal phase ( pregnanediol-3 alpha-glucuronide > 0.20 mu g mg(-1) creatinine) provid ed an accurate and reliable non-invasive system for monitoring reprodu ctive state and timing ovulation in this endangered primate. Urinary o estrone-3-conjugates were less accurate and reliable than pregnanediol -3 alpha-glucuronide: while plasma and urinary oestrone-3-conjugates w ere generally higher during the Luteal phase than during the follicula r phase, a marked increase in their concentration did not occur until 3-5 days after inferred ovulation.