Detection of urinary estrogen conjugates and creatinine using near infrared spectroscopy in Bornean orangutans (Pongo Pygmaeus).

For promoting in situ conservation, it is important to estimate the density distribution of fertile individuals, and there is a need for developing an easy monitoring method to discriminate between physiological states. To date, physiological state has generally been determined by measuring hormone concentration using radioimmunoassay or enzyme immunoassay (EIA) methods. However, these methods have rarely been applied in situ because of the requirements for a large amount of reagent, instruments, and a radioactive isotope. In addition, the proper storage of the sample (including urine and feces) on site until analysis is difficult. On the other hand, near infrared (NIR) spectroscopy requires no reagent and enables rapid measurement. In the present study, we attempted urinary NIR spectroscopy to determine the estrogen levels of orangutans in Japanese zoos and in the Danum Valley Conservation Area, Sabah, Malaysia. Reflectance NIR spectra were obtained from urine stored using a filter paper. Filter paper is easy to use to store dried urine, even in the wild. Urinary estrogen and creatinine concentrations measured by EIA were used as the reference data of partial least square (PLS) regression of urinary NIR spectra. High accuracies (R(2) > 0.68) were obtained in both estrogen and creatinine regression models. In addition, the PLS regressions in both standards showed higher accuracies (R(2) > 0.70). Therefore, the present study demonstrates that urinary NIR spectra have the potential to estimate the estrogen and creatinine concentrations.

Spectral pattern of urinary water as a biomarker of estrus in the giant panda.

Near infrared spectroscopy (NIRS) has been successfully used for non-invasive diagnosis of diseases and abnormalities where water spectral patterns are found to play an important role. The present study investigates water absorbance patterns indicative of estrus in the female giant panda. NIR spectra of urine samples were acquired from the same animal on a daily basis over three consecutive putative estrus periods. Characteristic water absorbance patterns based on 12 specific water absorbance bands were discovered, which displayed high urine spectral variation, suggesting that hydrogen-bonded water structures increase with estrus. Regression analysis of urine spectra and spectra of estrone-3-glucuronide standard concentrations at these water bands showed high correlation with estrogen levels. Cluster analysis of urine spectra grouped together estrus samples from different years. These results open a new avenue for using water structure as a molecular mirror for fast estrus detection.

Urinary C-peptide as a method for monitoring body mass changes in captive bonobos (Pan paniscus).

In recent years methodological improvements have allowed for more precise estimates of nutrient intake in wild primates. However, estimates of energetic condition have remained relatively imprecise due to the difficulties of estimating digestive efficiency and energy expenditure in these animals. In the absence of a reliable intake-expenditure calculation, a method is needed that directly links changes in energetic condition, such as body mass, to physiological changes that can be detected via markers in body excretions such as urine or feces. One promising marker is C-peptide, a metabolic byproduct of insulin synthesis. Here we present the results of a food restriction experiment carried out in a group of captive bonobos (Pan paniscus). We measured changes in food availability and body mass and determined urinary C-peptide levels with the help of a time-resolved fluoroimmunoassay routinely used for measuring C-peptide in human blood. Urinary C-peptide levels decreased during a period of food restriction and increased again when food availability was continuously increased. During this refeeding phase an increase in body mass was significantly correlated with an increase in urinary C-peptide levels. Our results suggest that urinary C-peptide levels are an accurate indicator of individual energy balance. In conclusion, measuring C-peptide in urine is a promising method to quantify the energetic condition of wild apes.

Glucosuria in captive okapi (Okapia johnstoni).

Eighteen of 38 captive okapi housed in the United States were found glucosuric by dipstick analysis. To confirm these findings, urine glucose concentrations of captive okapi from one collection (n = 10) were analyzed by two methods: urine dipstick analysis and quantitative analysis. Seven of these urine samples were positive for glucose by dipstick, with comparable glucose measurements by quantitative analysis. For a presumed normal control, okapi (n = 10) held in captivity within their native home range were tested for glucosuria by urine dipsticks; all were negative. Serum fructosamine (221-362 micromol/L) and insulin (9-45 pmol/L, 1.17-5.85 microU/ml) concentrations were determined from okapi (n = 6) with and without glucosuria with the use of results considered within normal limits for other ruminants. We conclude that glucosuria is a true finding in many apparently healthy captive okapi in the United States.

Validation of urinary cortisol as an indicator of hypothalamic-pituitary-adrenal function in the bearded emperor tamarin (Saguinus imperator subgrisescens).

The use of cortisol levels as a measure of stress is often complicated by the use of invasive techniques that may increase hypothalamic-pituitary-adrenal (HPA) axis activity during sample collection. The goal of this study was to collect samples noninvasively and validate an enzyme-immunoassay (EIA) for the measurement of cortisol in urine to quantify HPA axis activity in the bearded emperor tamarin (Saguinus imperator subgrisescens). Urine samples were collected from trained subjects between 0700 and 0730 hr during a 1-month period, and were pooled for immunological validation. We validated the assay immunologically by demonstrating specificity, accuracy, precision, and sensitivity. For biological validation of the assay, we showed that levels of urinary cortisol (in samples collected between 0700 and 1700 hr) varied significantly across the day. Cortisol concentration was lowest at 0700 hr, increased to a mid-morning peak (0900 hr), and declined across the remainder of the day in a typical mammalian circadian pattern. We thus demonstrate that urinary cortisol can be used to quantify HPA activity in S.i. subgrisescens.

Urinary testosterone-metabolite levels and dominance rank in male and female bonobos (Pan paniscus).

The correlation between testosterone (T) and dominance rank may vary among species, and is expected to become stronger as the importance of aggressive competition for rank increases. However, it may also vary among social situations within a species, showing a stronger correlation during socially unstable periods. Knowledge on this topic in great apes, especially in females, is scant. This study presents the first data on the relationship between T and dominance rank in both sexes of the bonobo ( Pan paniscus). For each period (four socially unstable and two stable ones), linear rank orders were determined and subsequently correlated with the accompanying mean urinary T-metabolite concentrations (measured as immunoreactive 5alpha-androstan-17alpha-ol-3-one). No correlation between these two variables was found for either sex among individuals during socially unstable or stable periods. Also, within an individual over the six periods, no relationship of T with rank could be demonstrated. These results suggest that either the outcomes of aggressions have no influence on T levels, or such clear outcomes appear insufficiently frequent to affect T levels over longer periods. Even during the unstable periods, the rate of aggressions was not higher than during stable periods, suggesting that frequencies of aggression have little effect on rank. Further analyses indeed demonstrated no correlation between frequencies of overall aggressions or any type of aggressive behavior separately, or rank. Perhaps factors other than the frequency of displayed aggressions alone have a marked influence on a bonobo's rank, for example, coalition partners. Overall, in bonobos, T apparently does not form a physiological reflection of social status.

Annual changes of urinary progesterone and estradiol-17beta of the Dugong (Dugong dugon) in captivity.

Levels of urinary progesterone and estradiol-17 beta were measured twice a week in a female dugong, Dugong dugon, in captivity for two years from April 1996 to April 1998. The dugong showed 14 ovarian cycles during the period of study. Concentrations of progesterone ranged from 0.01 ng/mg creatinine (Cr) to 1.94 ng/mg Cr and the length of estrous cycle was 53.6+/-8.6 (mean+/-SEM) days based on intervals of urinary progesterone peak-to-peak measurements. Concentrations of urinary estradiol-17 beta ranged from 0.9pg/mgCr to 23.7pg/mgCr, and tended to peak just prior to elevations of progesterone during the first year of study. This is the first report demonstrates that the ovulatory cycle of the dugong is about 50 days. The present findings suggest that measurement of urinary progesterone is a useful method to detect ovarian cycle of the dugong in captivity.

Chemosignalling of musth by individual wild African elephants (Loxodonta africana): implications for conservation and management.

Elephants have extraordinary olfactory receptive equipment, yet this sensory system has been only minimally investigated in wild elephants. We present an in-depth study of urinary chemical signals emitted by individual, behaviourally characterized, wild male African elephants, investigating whether these compounds were the same, accentuated, or diminished in comparison with captive individuals. Remarkably, most emitted chemicals were similar in captive and wild elephants with an exception traced to drought-induced dietary cyanates among wild males. We observed developmental changes predominated by the transition from acids and esters emitted by young males to alcohols and ketones released by older males. We determined that the ketones (2-butanone, acetone and 2-pentanone, and 2-nonanone) were considerably elevated during early musth, musth and late musth, respectively, suggesting that males communicate their condition via these compounds. The similarity to compounds released during musth by Asian male elephants that evoke conspecific bioresponses suggests the existence of species-free 'musth' signals. Our innovative techniques, which allow the recognition of precise sexual and musth states of individual elephants, can be helpful to managers of both wild and captive elephants. Such sampling may allow the more accurate categorization of the social and reproductive status of individual male elephants.

Cystinuria in the maned wolf of South America.

Of 42 maned wolves in zoos or live-trapped in Brazil, 34 had excessive cystine in their urine. Renal clearance studies of five of the affected wolves revealed a variable defect for the reabsorption of cystine and dibasic amino acids. The renal tubular handling of other solutes including glucose, phosphate, sodium, potassium, and uric acid was considered normal. Urinary calculi composed of cystine were found in four wolves and proved fatal in three of them. With the exception of the high incidence in this species, this hereditary disease resembles the disorder described in dogs and humans.

Estrogen excretory patterns in the Indian rhinoceros (Rhinoceros unicornis), determined by simplified urinary analysis.

Daily urine samples obtained at random from 3 mature Indian rhinoceroses (Rhinoceros unicornis) were evaluated for immunologic estrogen concentration and were indexed by creatinine (Cr) concentration. Chromatographic separation and enzyme hydrolysis of the estrogenic components indicated that the major urinary estrogen in this species is immunoreactive estrone (greater than 95%). Cyclic variations of immunoreactive estrogens (basal values of 0.1 to 0.3 microgram/mg of Cr. peak values of 5.8 to 12.5 microgram/mg of Cr) were observed at an interval of 43 +/- 2 days (4 cycles) which appear to reflect the apparent ovarian cycles. The method presented offers a practical approach for the monitoring of ovarian events in large, nontractable species.

Monitoring the estrous cycle of the Asian elephant (Elephas maximus), using urinary estrogens.

The estrous cycle of the Asian elephant (Elephas maximus) was monitored by analysis of urinary estrogens. Daily morning urine samples were analyzed for estrone (E1), estradiol (E2), and total immunoreactive estrogen (ET). The ET values were shown to correlate poorly with E1 and E2 values and failed to reveal any patterns of reproductive cycling. Daily E1 and E2 values, indexed by creatinine concentrations, demonstrated cyclic profiles in those samples of sufficient concentration. The technique offered a simple, noninvasive method of documenting ovarian function in the elephant.

Amylase iso-enzymes in primates of the families Lemuridae, Cebidae, Cercopithecidae, Hylobatidae and Pongidae.

This paper presents the first data in the alpha-amylase iso-enzymes in primates of the families: Lemuridae, Cebidae, Cercopithecidae, Hylobatidae and Pongidae. By means of agar-gel electrophoresis of urine samples from 33 individuals belonging to ten species of the above mentioned families a total of 14 different variants of amylase heterogeneity were found.