Endocrinology of pregnancy in the orang-utan (Pongo pygmaeus) and its evolutionary significance

Urinary concentrations of estrone, estradiol-17Β, estriol, pregnanediol-3α-glucuronide, and chorionic gonadotrophin (CG) were measured by radio-immunoassy through five pregnancies in four multiparous orang-utans. The excretion of all three estrogen metabolites increased substantially during pregnancy. Although estrone was the major metabolite during early pregnancy, estriol excretion increased considerably, to reach 10 times the concentration of estrone at term. Estradiol-17Β was of comparatively minor importance. Maximum CG excretion occurred during the first trimester and low but constant levels were present in urine throughout the remainder of pregnancy. An early peak of pregnanediol-3α-glucuronide excretion coincided with the CG peak and then rose steadily to reach a plateau 8 weeks prepartum which was maintained until term. Urinary excretion of all five hormones decreased rapidly immediately following parturition. These data suggest that the pattern of urinary steroid and CG excretion during pregnancy in the orang-utan closely resembles that in the other great apes and women.     

Menstrual cycle characterization and artificial insemination in the black mangabey (Cercocebus aterrimus)

Concentrations of immunoreactive estrone conjugates, pregnanediol-3-glucuronide, and luteinizing hormone were measured and indexed to creatinine in daily urine samples from three female black mangabeys (Cercocebus aterrimus). Daily observations of menstruation and perineal tumescence were recorded. The mean ± SEM lengths of the menstrual cycle [apparent cycle length of 26.0 ± 0.8 days determined by observation of intermenstrual intervals (n = 26); physiologic cycle length of 31.3 ± 5 days determined by urinary endocrine analysis (n = 4)], follicular phase [16.5 ± 4 days (n = 4)], and luteal phase [14.8 ± 1 day (n = 4)] were determined. The apparent cycle length is probably more accurate. Perineal tumescence began during or shortly after menstruation, increased concomitantly with increasing follicular phase conjugated estrone values, and reached maximal size in the periovulatory period. Ovulation was closely followed by a drop in conjugated estrone levels, an increase in urinary pregnanediol-3-glucuronide, and perineal detumescence. Peak concentrations of conjugated estrone and luteinizing hormone values were coincident. Pregnanediol-3-glucuronide accurately reflected luteal function in the black mangabey. Knowledge of the menstrual cycle parameters and their correlation to perineal tumescence was used to time artificial inseminations. Semen was obtained by rectal electroejaculation. Coagulum and extended semen, or trypsin-digested coagulum, were used for insemination. One insemination of trypsin-digested coagulum at the external os of the cervix resulted in a probable conception, follówed by apparent abortion after 3 weeks.     

Urinary steroid evaluations to monitor ovarian function in exotic ungulates: V. Estrogen and pregnanediol-3-glucuronide excretion in the black rhinoceros (Diceros bicornis)

A study of female black rhinoceros (Diceros bicomis) urinary steroid and steroid metabolite excretion was performed to determine if techniques useful for monitoring reproductive events in the Indian rhinoceros (Rhinoceros unicornis) could be utilized to evaluate the black rhinoceros. Urine samples from 19 zoo-held black rhinoceros were analyzed for estrogen, estrone conjugates (EC), and pregnanediol-3-glucuronide (PDG) content by direct radioimmunoassays. Estrogen analysis revealed that >95% of the estrogens present in female black rhinoceros urine are conjugated, with estrone and estradiol accounting for virtually all of these estrogens. There is no observable difference in the amount of estrogen present in estrus; postestrus; and early-, mid-, and late-gestation urine samples. Analysis of serial urine samples for EC failed to reveal any discernible levels or patterns which reflected reproductive status. Neither nonpregnant nor early-gestational female black rhinoceros' urine samples contained detectable amounts of PDG. Urinary PDG concentrations became measurable in midgestation (9–12 months prior to parturition) and rose steadily throughout the remainder of gestation. PDG levels declined sharply and became nondetectable 1 day postpartum. Though a wide range in PDG levels was observed among individual pregnant animals, each female consistently excreted increasing amounts of PDG through latter pregnancy.     

Urinary steroid evaluations to monitor ovarian function in exotic ungulates: III. Estrone sulfate and pregnanediol-3-glucuronide excretion in the Indian rhinoceros (Rhinoceros unicornis)

A study was undertaken to identify urinary estrogen and progesterone metabolites in the female Indian rhinoceros (Rhinoceros unicornis). Measurements of these metabolites were then used to monitor ovarian function and establish normal levels and patterns of steroid excretion during the estrous cycle and pregnancy. Urine samples were analyzed for estrone sulfate and pregnanediol-3-glucuronide (PDG) by direct radioimmunoassays. Both hormones produced discrete profiles reflecting ovarian activity in nonconceptive cycles. The estrous cycle was observed to be 48 days (range 39–64) with a mean follicular phase of 14.8 days (range 13–19), followed by a mean luteal phase of 19 days (range 17–21). Of the single gestation monitored, PDG levels rose above luteal phase levels by the third month after breeding and remained elevated throughout gestation. The combined estrogen and progesterone metabolite profiles present a complete evaluation of ovarian steriod production in the mature female Indian rhinoceros.     

Monitoring fecal samples for estrogen excretion across the ovarian cycle in Goeldi's monkey (Callimico goeldii)

In captive Goeldi's monkeys, estrogen concentration was determined in fecal samples collected from 4 cycling/unmated females and 4 postpartum/mated females in order to ascertain the potential of fecal estrogen monitoring for providing basic information about reproductive status in this endangered Amazonian monkey. Subjects were fed an omnivorous diet and first-void feces were collected in the home cage at 1–3-day intervals for 30–50 days from the cycling females, and at 6–14-day intervals around the estimated time of the postpartum ovulation in each of the 4 mated females. Estimates for the duration of ovarian cycles (22–26 days) and the timing of ovulation were based on cyclic profiles of either blood progesterone or urinary pregnanediol-3α-glucuronide. Fecal estrogen values were normalized using these plasma or urinary profiles. HPLC analysis of estrogen from postpartum fecal samples demonstrated the presence of unconjugated estrone and estradiol-17β (“unconjugated estrogen”). Unconjugated estrogen was extracted and its fecal concentration estimated via EIA. The correlation (r) between plasma estrone conjugates and fecal unconjugated estrogen across nonconception ovarian cycles was 0.65 and measurement of the latter generated cyclic profiles. A range of 4–36-ng unconjugated estrogen g^?1 feces was identified for follicular phases of nonconception cycles. Fecal unconjugated estrogen first exceeded the concentration range of the follicular 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 than follicular phase concentrations. Each of the 4 mated females conceived at its postpartum ovulation; concentrations of fecal unconjugated estrogen excreted by 3 of these females demonstrated a marked postovulatory increase. This study demonstrates that fecal unconjugated estrogen can be applied to monitor ovarian cyclicity in Goeldi's monkey. © 1994 Wiley-Liss, Inc.     

Steroid metabolism and validation of noninvasive endocrine monitoring in the African wild dog (Lycaon pictus)

The purpose of this study was to validate noninvasive endocrine monitoring techniques for African wild dogs (Lycaon pictus) and to establish physiological validity of these methods by evaluating longitudinal reproductive-endocrine profiles in captive individuals. To determine the primary excretory by-products of ovarian steroid metabolism, [¹⁴C]-progesterone and [³H]-estradiol were co-administered to a female and all excreta were collected for 80 hr postinjection. Radiolabel excretion peaked ≤ 18 hr postinfusion, and progesterone and estradiol metabolites were excreted in almost equivalent proportions in urine (39.7 and 41.1%, respectively) and feces (60.3 and 58.9%, respectively). Most of the urinary metabolites were conjugated (estradiol, 94.3 ± 0.3%; progesterone, 90.4 ± 0.5%), so that immunoassays for pregnanediol-3α-glucuronide (PdG) and estrogen conjugates (EC) were effective for assessing steroid metabolites. Two immunoreactive estrogens (estradiol and estrone) and at least one immunoreactive progesterone metabolite (3α-hydroxy-5α, pregnan-20-one) were detected in feces. Urine and fecal samples were collected (1–3 times per week) for 1.5 yr from one adult female and two adult males to assess longitudinal steroid metabolite excretion. Overall correlation of urinary PdG to matched, same-day fecal progesterone metabolites immunoreactivity was 0.38 (n = 71, P < 0.05). Similarly, urinary EC was correlated (P < 0.05) with same-day fecal estrogen immunoreactivity (r = 0.49, n = 71). During pregnancy and nonpregnant cycles, copulation occurred at the time of peak (or declining) estrogen metabolites and increasing progesterone metabolites concentrations. Estrus duration was 6–9 days and gestation lasted 69 days with parturition occurring coincident with a drop in progesterone metabolites. Males exhibited seasonal trends in fecal testosterone excretion with maximal concentrations from July to September coincident with peak mating activity. Although these limited longitudinal hormone profiles should be interpreted cautiously, noninvasive gonadal steroid monitoring suggests that: (1) both female and male wild dogs may exhibit reproductive seasonality in North America, (2) females are monoestrous, and (3) peak testicular activity occurs between August and October coincident with mating behavior. From a conservation perspective, noninvasive endocrine monitoring techniques should be useful for augmenting captive breeding programs, as well as for developing an improved understanding of the physiological mechanisms underlying reproductive suppression in response to social and ecological pressures. Zoo Biol 16:533–548, 1997. © 1997 Wiley-Liss, Inc.     

Monitoring ovarian function in marmosets and tamarins by the measurement of urinary estrogen metabolites

Practical aspects of urinary estrogen analysis were considered with regard to establishing simple and reliable methods for monitoring ovarian function in marmosets and tamarins. Changes in the hormone:creatinine ratio in small volumes of urine from the common marmoset were significantly correlated with changes in 24-h excretion. Comparison of the metabolism and excretion of estrogens during the ovarian cycle in the common marmoset and cottontop tamarin revealed interesting species differences. High concentrations of conjugated estrone were measured in marmoset plasma, but estradiol 17β was the predominant estrogen in urine. In contrast, estrone was the most abundant estrogen measured in tamarin urine. Both species excreted very little estriol. Sulfates and glucuronides were present in urine in similar proportions before ovulation in the marmoset, although after ovulation sulfates were the more abundant. Conversely, most of the estrogens in tamarin urine appeared to be conjugated as glucuronides. Direct assay for estrone sulfate was applied to the measurement of urinary estrogen excretion during the ovarian cycle in a marmoset. The results compared well with those for total estradiol 17β after hydrolysis and ether extraction. The use of direct assays for conjugated estrogens in small volumes of urine is suggested as a practical method for monitoring ovarian function in marmosets and tamarins.     

Direct measurements of urinary estrone conjugates during the normal menstrual cycle of the gorilla (Gorilla gorilla)

A direct immunoassay for urinary estrone conjugates (estrone sulfate and estrone glucuronide) was used to assess the preovulatory estrogen rise in normal gorilla menstrual cycles. Immunoreactive estrone conjugates in samples concomitantly assessed for total estrogen immunoreactivity reflected similar profiles throughout the cycle; however, the speed and resolution of the direct assay for conjugates indicate this method to be more accurate in monitoring ovulation than the measurement of total immunoreactive estrogens. In a single conceptive ovarian cycle, urinary estrone conjugate continued to rise in the luteal phase, indicating that this test may also be useful for detecting early pregnancy. The application of this technique provides clear profile of ovarian function in gorillas as well as in other primate species.     

Sexual behavior and urinary ovarian hormone concentrations during the lowland Gorilla menstrual cycle

Sexual behaviors were recorded and urinary concentrations of total estrogens and pregnanediol-3-glucuronide (Pdg) measured during six normal menstrual cycles from two female lowland gorillas in a stable, captive group. Frequencies of female presentations, mounts, and copulations were positively associated with peak estrogen values but not with elevations of Pdg. These results support the observation that sexual behaviors in the gorilla occur most frequently in the periovulatory period and that copulations serve primarily a sexual function.     

Use of monoclonal antibodies to pregnanediol-3α-glucuronide for the development of a solid phase chemiluminescence immunoassay

Monoclonal antibodies to pregnanediol-3α-glucuronide were produced by hybridomas between P3-X63-Ag8 variants and spleen cell of mice immunized with a bovine serum albumin conjugate of the homologous hapten. The ascites fluid collected from mice inoculated with the cloned hybridoma cells contained antibodies with high specifity and affinity to pregnanediol-3α-glucuronide. A sensitive solid-phase chemiluminescence immunoassay for urinary pregnanediol-3α-glucuronide was established utilizing these antibodies. The assay was validated in terms of specificity, accuracy, sensitivity and precision. When urine samples were assayed for pregnanediol-3α-glucuronide, the results obtained by the solid-phase chemiluminescence immunoassay method and the conventional gas liquid chromatographic method agreed well (n = 30, r=0.96). The method may be of value for monitoring luteal function since it is fast, sensitive and does not require the use of radioisotopes or purification of the biological sample. Monoclonal antibody preparations facilitate rigorous standardization of the assay.     

Analysis of urinary immunoreactive steroid metabolites and gonadotropins for characterization of the estrous cycle,breeding period,and seasonal estrous activity of captive killer whales (Orcinus orca)

To increase the basic understanding of killer whale (Orcinus orca) reproductive physiology necessary for the development of artificial breeding programs, we utilized radioimmunoassays (RIA) to detect urinary immunoreactive steroid metabolites (pregnanediol-3α-glucuronide [PdG] and estrone-conjugates [EC]) and gonadotropins (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]) in urine samples from six female killer whales. Urine samples were collected from the whales by voluntary presentation behavior over a 2- to 4-year period. All urinary hormone values were corrected for intersample urine concentration variations by indexing with creatinine. Daily urine samples from four whales were collected during two conceptions and 18 complete estrous cycles. LH, FSH, EC, and PdG immunoreactive levels were determined and combined with observed copulatory activity in five cycles, including two conceptive cycles from two whales. Mean luteal phase lengths ranged from 9.7 to 19.2 days. Mean follicular phase lengths ranged from 6.5 to 16.8 days. Mean estrous cycle lengths based on the first detectable PdG levels were 41.6 ± 6.72 S.E.M. days. After PdG nadir, immunoreactive FSH levels showed a bimodal pattern with the first peak being greater in size, and both preceding a follicular phase EC increase. LH levels > the 95% confidence interval of the mean were considered significant. Combined LH immunoreactive values from whales 2 and 6 during two and three estrous cycles, respectively, had significant LH peak concentrations on day minus 2. These significant LH peaks were assumed to represent the preovulatory LH surge. Eight copulations during two conceptive cycles were observed between whales 2 and 6 and a breeding male. Six of these copulations (3 with each female whale) occurred within 72 hours of the beginning or the end of the presumptive preovulatory LH surge. Estrous activity was seen throughout the year for the herd. However, individuals had varying periods of anestrus that could not be linked to environmental, social, or nutritional influences. The whales that were reproductively successful had anestrus intervals that were usually influenced by gestation, postparturient period, or lactation. The information obtained during this research enhances the foundation for future artificial reproductive management techniques. © 1993 Wiley-Liss, Inc.     

Radioimmunoassay of 16 alpha-hydroxyestrone in human urine

A radioimmunoassay for the quantitation of the sum of free, glucuronidated and urine is described. The method is reliable and accurate. Using this method, urinary excretion of 16 alpha-hydroxyestrone was determined in normal men, premenopausal women, and postmenopausal women. The values were compared to the urinary excretion of estrone and estradiol. In two women, the urinary excretion of the three estrogens was measured in daily samples throughout a normal menstrual cycle. We conclude that 16 alpha-hydroxyestrone is a quantitatively important urinary estrogen. Inclusion of the measurement of 16 alpha-hydroxyestrone should yield a more accurate assessment of estrogen metabolism.     

Urinary concentrations of ovarian steroid hormone metabolites and bioactive follicle-stimulating hormone in killer whales (Orcinus orchus) during ovarian cycles and pregnancy

Reproductive hormone profiles of six captive killer whales (Orcinu orcus) from three Sea World aquaria were studied for intervals up to 2 yr. Daily urine samples and bimonthly blood samples were collected and analyzed for hormone concentration. Immunoreactive estrone conjugates, pregnanediol-3-glucoruonide, 20-alpha-hydroxyprogesterone as well as bioactive follicle-stimulating hormone (FSH) were measured in urine samples and indexed by creatinine concentrations of the same sample. In selected cases, serum progesterone concentrations were also measured. Three of the animals in the study became pregnant during the study period and two of these animals were evaluated during the time of conception and throughout most of gestation. From the data of the three animals that conceived, hormone profiles of the complete ovarian cycle, early pregnancy, and mid- to late gestation are described. The remaining three animals did not conceive and only one of these demonstrated hormone changes that indicated regular ovarian activity. The female reproductive pattern of the killer whale is characterized by a gestation of 17 mo and an ovarian cycle of 6-7 wk in duration. The hormone changes associated with the ovarian cycle of the killer whale are similar to those of most other mammalian species. A bimodal pattern of bioactive FSH with a pronounced rise of estrogen predominates the preovulatory hormone profile. After ovulation, increased progesterone production is observed for approximately 4 wk in the nonconceptive ovarian cycle. During the luteal phase and early pregnancy, when progesterone metabolites are elevated, estrogen metabolite excretion remains low. These data extend the application of urine collections for longitudinal studies involving hormone changes, particularly those involving nondomesticated species.(ABSTRACT TRUNCATED AT 250 WORDS)     

Monitoring ovulation and implantation in the cynomolgus macaque (Macaca fascicularis) through evaluations of urinary estrone conjugates and progesterone metabolites: a technique for the routine evaluation of reproductive parameters

Investigations were undertaken to determine the applicability of recently reported specific radioimmunoassays for urinary estrone conjugates and progesterone metabolites for monitoring ovarian function in the cynomolgus macaque (Macaca fasciularis) and other macaque species. Mean estrone conjugate measurements appear to accurately reflect the preovulatory estrogen peak in both conceptive (n = 5) and nonconceptive (n = 6) cycles, as well as to indicate early pregnancy through increases which are significantly elevated by Day + 15 (p less than 0.049) post estrone conjugates peak. The mean luteal phase levels of these progesterone metabolites are significantly elevated by Day + 14 (p less than 0.012) in conceptive cycles when compared to the mean values for nonconceptive cycles.     

Measurement of glucuronometabolites of 17 beta-estradiol and progesterone in diluted overnight urine. An approach to the study of luteal insufficiency

The determination of the concentrations of estrone-3-glucuronide, pregnanediol-3-glucuronide and luteinizing hormone has been performed in early morning urine samples of 14 normal menstruating women using a timed and measured volume urine collection procedure. In order to investigate the variability of the urinary hormonal concentrations due to day-to-day differences in diuresis, the absolute hormonal concentrations have been corrected either for the urinary creatinine excretion or for the volume of urine voided during the night. The results demonstrate that both correction factors are able to reduce substantially the coefficient of variation values in comparison to the absolute hormonal concentrations. The urinary test of ovarian function has been performed in 11 infertile women affected by luteal insufficiency using the same procedure, and the hormonal profiles showed some alterations in both estrone-3-glucuronide and pregnanediol-3-glucuronide concentrations in comparison to the hormonal profiles of the normal subjects. Such alterations were significant in the single subject when integrated values of the hormonal data in defined time intervals were investigated.     

Urinary hormone analysis as a diagnostic tool to evaluate the ovarian function of female gorillas (Gorilla gorilla)

Daily urine samples were collected from 4 adult female gorillas over 7 menstrual cycles. Urinary oestrone conjugate and pregnanediol-3-glucuronide (PDG) were measured by radioimmunoassay; LH was measured by enzyme immunoassay and each hormone was indexed by creatinine. The quantity of urinary LH during the ovulatory surge was positively correlated with the quantity of PDG excreted during the luteal phase (r = 0.87, P = 0.0013). The observations indicate a relationship between the quality of the LH surge and the levels of PDG in the luteal phase and suggest that both the LH surge and subsequent luteal phase function may be predictable from the oestrogen excretion profile during the follicular phase.     

Measurement of urinary and fecal steroid metabolites during the ovarian cycle in captive and wild Japanese macaques, Macaca fuscata

We measured the concentration of steroid hormones from urine, feces, and blood samples of two captive Japanese macaques, Macaca fuscata, during nonconceptive ovarian cycles to compare the patterns of the excreted steroids with those of circulating steroids. Urine and feces were analyzed for estrone conjugates (E1C) and pregnanediol-3-glucronide (PdG) using enzyme immunoassays (EIAs), while plasma was analyzed for estradiol-17beta(E2), progesterone (P), and luteinizing hormone (LH) using radioimmunoassays (RIAs). Urinary and fecal E1C and PdG levels were approximately parallel to plasma E2 and P levels, respectively. The E1C profiles of daily urinary and fecal samples revealed a midcycle peak, followed by a sustained PdG increase lasting up to two weeks from the E1C peak. A fecal E1C peak was one day later than the urinary E1C peak. One of the captive females exhibited a discrete plasma LH peak, one indicator that ovulation has occurred, on the day following the urinary E1C peak, i.e., the same day of fecal E1C peak. We measured excreted steroids in nine wild females and determined the timing of ovulation by comparing fecal steroid profiles to those obtained in captive monkeys. Data from wild females indicated that eight of nine females conceived during their first ovulatory cycle of the sampling period, whereas the remaining female failed to conceive during the sampling period even though she ovulated. In the eight females that conceived, E1C increased again following the detected or estimated E1C peak, with levels comparable to the preovulatory peak levels, and sustained elevations of PdG for over 40 days. These data illustrate that the urinary and fecal profiles of ovarian steroid excretion obtained through the application of these noninvasive techniques provide an accurate approach for monitoring conceptive and nonconceptive ovarian cycle in captive and free-living Japanese macaques.     

Urinary steroid evaluations to monitor ovarian function in exotic ungulates: VIII. Correspondence of urinary and plasma steroids in the llama (Lama glama) during nonconceptive and conceptive cycles

Ovarian function was evaluated in mature female llamas (n = 2) during seven ovulations in 2 conceptive and 5 nonconceptive ovarian cycles by measuring urinary and plasma hormone concentrations. Ovulation was induced by three different methods; administration of gonadotropin-releasing hormone (GnRH), copulation with a vasectomized male and copulation with an intact male. Plasma estradiol and progesterone concentrations, and urinary concentrations of estrogen conjugates and two progesterone metabolites, pregnanediol-3-glucuronide (PdG), and immunoreactive (iPdG), concentrations were compared to determine their value in monitoring ovarian function. Estrogen concentrations in urine corresponded to estradiol levels in plasma and accurately reflected changes in follicular activity when evaluated over several daily samples. Plasma progesterone and urinary iPdG were reliable indicators of luteal function. These data represent the first comparison of blood and urinary hormone measurements for monitoring the complete ovarian cycle of an ungulate, and demonstrates that either can be used to assess changes in ovarian activity in this species.     

Changes of urinary steroid conjugates and gonadotropin excretion in the menstrual cycle and pregnancy in the Yunnan snub-nosed monkey (Rhinopithecus bieti).

The Yunnan snub-nosed monkey (Rhinopithecus bieti) is one of the most endangered species in the world, and it is endemic to China. According to our knowledge, there was no information on reproduction for this species. The present study was designed to understand the characteristics of reproductive hormone secretion during the menstrual cycle and pregnancy of this species by monitoring urinary estrone conjugate (E1C), pregnanediol-3-glucuronide (PdG), bioactive follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The urine samples were collected each day from four adult females for eight menstrual cycles, and once in 3 days during pregnancy (three full-term pregnancies, one mid-term abortion). The steroid conjugate was tested by radioimmunoassays (RIAs), and bioactive FSH and LH levels were measured in vitro by the sensitive bioassays granulosa cell aromatize bioassay (GAB) and rat interstitial cell testosterone (RICT), respectively. The results showed that: 1) E1C presented a preovulatory peak (183.9 +/- 8.6 ng/mgCr) followed by a definite elevation of PdG; 2) PdG in the luteal phase (754.4 +/- 30.6 ng/mgCr) was three- to fivefold higher than during the corresponding follicular phase (198.3 +/- 11.4 ng/mgCr); 3) the peaks of bio-LH and bio-FSH were on the same day, while the E1C peak was 1 or 2 days before the peaks for these two hormones; 4) bio-FSH levels were higher in the follicular phase than in the luteal phase, and bio-LH levels elevated slightly in the luteal phase; 5) the mean cycle length was 23.6 +/- 3.5 days (n = 3) based upon successive urinary LH peaks; 6) based on the interval from the day of E1C peak to the day of parturition, the gestation was 203.7 +/- 2.5 days (n = 3); and 7) both E1C and PdG increased and remained high after pregnancy, with a sharp decrease in basal levels following parturition or mid-term abortion. The results suggested that the pattern of reproductive hormones for R. bieti is similar to that of other Old World monkeys, but the concentration of the hormones is different from that of other species. This species has a longer progestation period, which may be related to its classification status.     

The use of a urinary estrone conjugates assay for detection of optimal mating time in the cynomolgus macaque (Macaca fascicularis)

Forty-four female cynomolgus macaques (Macaca fascicularis) were examined to determine the optimum fertile period for mating. Daily urinary estrone conjugates (E1C) were measured, beginning on day 7 of the menstrual cycle, until a 1.5-gold E1C rise above the baseline was detected. The females were bred the next morning. Pregnancies were verified in all animals at day 18 postbreeding, and/or on day 25 postbreeding. Serum progesterone levels were used to correlate the relationship between ovulation and the E1C peak. Forty-four of the 57 cycles indicated a urinary E1C peak between days 10-15 of the menstrual cycle; this peak occurred on the day following the initial 1.5-fold to twofold rise in 90% of the cycles. A single 2-hr mating period the day before, the day of, or the day after the E1C peak resulted in conception in 17 of 44 (38.6%) animals.