Urinary androgen and corticoid levels in captive, male Western lowland gorillas (Gorilla g. gorilla): age- and social group-related differences.

Urinary androgen and corticoid levels were measured for 52 captive male Western lowland gorillas to examine age-related variance and potential differences resulting from various social situations. Significant diurnal variation was present in both hormones. Age-related differences in androgens revealed that males experienced two stages of androgen increase and one stage of decrease: increases occurred from juvenile (less than 10 yr of age) to subadult (between 10-13 yr) and subadult to young adult (14-20 yr), whereas decreases occurred from young adult to adult (> 20 yr). Age-related differences in corticoid levels varied depending on the time of day, but morning corticoids were greatest in juvenile males, followed by young adult males. The type of social grouping was associated with differences in corticoid levels, as animals housed socially (in either a heterosexual or all-male group) had similar corticoid levels, whereas solitary males showed greater corticoid levels than their socially-housed counterparts. The increased levels of corticoids in solitary-housed males suggest this management strategy might not be optimal, although more data are needed. Additionally, the significantly greater levels of androgens and corticoids in young adult male gorillas may present management challenges, and thus zoos may need to consider increasing the flexibility of their current management practices with respect to males.     

Declining and low fecal corticoids are associated with distress, not acclimation to stress, during the translocation of African rhinoceros

Concentrations of adrenal steroid metabolites in feces are routinely used to assess the welfare of animals that are the subject of conservation efforts. The assumption that low and declining corticoid concentrations indicate the absence of stress and acclimation, respectively, is often made without experimental support or wild-animal comparisons, although intrinsic control of adrenal steroids might occur even under ongoing stress and distress. We adopted the capture and 11-week captivity of 18 black ( Diceros bicornis : 11 males, seven females) and 52 white ( Ceratotherium simum : 22 males, 30 females) rhinoceros as an experimental test of the relationship between corticoid concentrations and stress (translocation) and measured for suppressed gonad function as an indicator of distress – the biological cost of cumulative stressors. Fecal samples collected from the rectum at capture and during captivity were stored frozen and their corticoid, and androgen (in males) or progestin (in females), concentrations determined by radioimmunoassay. Corticoid profiles followed the expected pattern of being two to five times pre-capture levels (ng g⁻¹: black rhino: female 24.5±3.7, male 23.9±2.2; white rhino: female 16.3±1.6, male 12.3±2.4) for up to 17 days after capture and declined with time in captivity. Black rhinoceros and male white rhinoceros corticoids declined below pre-capture values and were associated with suppressed levels of androgens and progestins with increased time in captivity. Declining corticoids could not be interpreted as acclimation or the absence of stressors, without also measuring for distress in African rhinoceros. White rhinoceros female corticoid values remained elevated, although their gonad steroid levels were also suppressed. We discuss our findings for the management of rhinoceros in the wild and captivity.     

Development of co-feeding relationships in immature free-ranging Japanese monkeys (Macaca fuscata fuscata)

The co-feeding relationships of immature Japanese monkeys in the provisioned situation were studied. The most frequent co-feeders for immature females were diversified as compared to those for immature males. The number of immature females who showed strong co-feeding relationships with their mothers gradually decreased with age in both high- and middle/low-ranking matrilines, but the percent decrease was greater for middle/low-ranking immatures. Almost all immature females who displayed strong co-feeding relationships with adult males were from middle/low-ranking matrilines. Strong co-feeding relationships with mothers among immature males from high-ranking matrilines remained until 4 years of age. In contrast, strong co-feeding relationships with mothers among middle/low-ranking immature males decreased rapidly in the first year of life, and most 1- to 4-year-olds showed no strong co-feeding relationships with other group members. It is considered that middle/low-ranking mothers may not provide their immatures with a secure base for obtaining food in the provisioned situation.     

Evidence for chronic stress in captive but not free-ranging cheetahs (Acinonyx jubatus) based on adrenal morphology and function

The cheetah (Acinonyx jubatus) is highly endangered because of loss of habitat in the wild and failure to thrive in captivity. Cheetahs in zoos reproduce poorly and have high prevalences of unusual diseases that cause morbidity and mortality. These diseases are rarely observed in free-ranging cheetahs but have been documented in cheetahs that have been captured and held in captive settings either temporarily or permanently. Because captivity may be stressful for this species and stress is suspected as contributing to poor health and reproduction, this study aimed to measure chronic stress by comparing baseline concentrations of fecal corticoid metabolites and adrenal gland morphology between captive and free-ranging cheetahs. Additionally, concentrations of estradiol and testosterone metabolites were quantified to determine whether concentrations of gonadal steroids correlated with corticoid concentration and to assure that corticosteroids in the free-ranging samples were not altered by environmental conditions. Concetntrations of fecal corticoids, estradiol, and testosterone were quantified by radioimmunoassay in 20 free-ranging and 20 captive cheetahs from samples collected between 1994 and 1999. Concentrations of baseline fecal corticoids were significantly higher (p = 0.005) in captive cheetahs (196.08 +/- 36.20 ng/g dry feces) than free-ranging cheetahs (71.40 +/- 14.35 ng/g dry feces). Testosterone concentrations were lower in captive male cheetahs (9.09 +/- 2.84 ng/g dry feces) than in free-ranging cheetahs (34.52 +/- 12.11 ng/g dry feces), which suggests suppression by elevated corticoids in the captive males. Evidence for similar sulppression of estradiol concentrations in females was not present. Adrenal corticomedullary ratios were determined on midsagittal sections of adrenal glands from 13 free-ranging and 13 captive cheetahs obtained between 1991 and 2002. The degree of vacuolation of cortical cells in the zona fasciculata was graded for each animal. Corticomedullary ratios were larger (p = 0.05) in captive cheetahs; however, there was no difference (p = 0.31) in the degree of corticocyte vacnolation between the two populations. These data proxile both mnorphologic and functional evidence suggestive of chronic stress in captive cheetahs. Further research into the role of hypercortisolemia in the pathogenesis of the reproductive abnormalities and unusual diseases of captive cheetahs is needed.     

Endocrine and behavioral correlates of drought in wild olive baboons (Papio anubis)

As part of a long-term study in behavioral endocrinology, wild olive baboons (Papio anubis) living in the Serengeti ecosystem of East Africa have been under study since 1978. The present report documents behavioral and endocrine changes associated with the severe drought of 1984. During this time, the annual rainy season failed and grassland biomass was severely reduced in the Serengeti. Baboons were able to maintain body weight but spent significantly more time foraging for food. In four prior years of study, basal testosterone concentrations were remarkably stable in adult and subadult males. In contrast, during the drought, there was a highly significant 60% decline in basal concentrations of the steroid. This testicular suppression was apparent in males of all ranks (by approach-avoidance criteria). Prior studies with this population, which examined the role of acute and chronic stressors in similarly suppressing testosterone concentrations, suggested that the present instance was in response to the stress of the drought. The drought was also associated with significant reductions in the rates of escalated aggression among males. However, the distribution of fights between high-ranking males, between low-ranking males, and between high- and low-ranking males did not change from prior years, nor was the dominance hierarchy inordinately unstable during this time. These findings agree with previous evidence that indicates that suppressed testosterone concentrations in males can be associated with lower rates of aggressive behaviors but that the steroid plays a predominantly facilitative rather than activational role. Finally, rates of approach-avoidance interactions and of male sexual behaviors were unchanged during the drought. These findings agree with an endocrine literature that indicates that reproductive behavior or physiology in primates is rarely disrupted by suppression of testosterone concentrations of the magnitude of the present case.     

Noninvasive assessment of adrenal activity associated with husbandry and behavioral factors in the North American clouded leopard population

The North American clouded leopard (Neofelis nebulosa) population is far from self‐sustaining. Breeding success is poor and behavioral problems (i.e., fur‐plucking, tail‐chewing, excessive hiding or pacing, and intersexual aggression that results in mate killing) are common. This study was undertaken to investigate whether some of these problems may be indicators of chronic stress (as reflected by persistently elevated glucocorticoid levels) and whether they are associated with specific management factors. A fecal corticoid metabolite assay was validated to monitor adrenal activity in clouded leopards. Adrenocorticotropic hormone (ACTH) challenges conducted in four clouded leopards established the biological relevance of the assay system. Fecal corticoid concentrations increased 14‐fold above baseline within 24 hours after ACTH administration. Adrenal activity then was monitored in 72 (36 males; 36 females) clouded leopards (65% of the North American Species Survival Plan population) during a 6‐week period and compared to husbandry and behavior data. There was a significant (P < 0.01) gender difference in fecal corticoid concentrations, with females producing higher concentrations than males. Multiple regression analyses revealed negative associations (P < 0.01) between enclosure height, number of hours keepers spent with each animal per week, and corticoid concentrations. A positive correlation (P < 0.001) was found between the number of keepers caring for an individual and corticoid concentrations. Higher fecal corticoid concentrations (P ≤ 0.05) were measured in clouded leopards kept on public display or near potential predators compared to individuals maintained off exhibit or in the absence of predators. Individuals that performed self‐injuring behaviors also had elevated fecal corticoids (P < 0.01). Spearman‐rank correlation analysis of keeper ratings and hormone data revealed positive associations (P ≤ 0.05) between some behaviors (pace, sleep, hide, and fearful/tense) and fecal corticoid concentrations. Overall these results indicate that noninvasive fecal corticoid monitoring has enormous potential for investigating how management and behavioral problems are related to animal well‐being. If conducted under carefully controlled experimental paradigms, this technique could allow researchers and managers to identify problem areas of captive management for clouded leopards (e.g., enclosure height, keeper time) and evaluate the efficacy of strategies designed to promote animal welfare and increased reproductive success. Zoo Biol 21:77–98, 2002. © 2002 Wiley‐Liss, Inc.     

Hormonal changes in the mare and foal associated with oxytocin induction of parturition.

Oxytocin was used to induce parturition in 6 mares and to determine the hormonal changes occurring during and for 72 h after parturition in the mares and their foals. Normal, healthy foals were born shortly (about 34 min) after a single i.m. injection of 40 or 60 i.u. oxytocin. There was no retention of fetal membranes and all mares produced ample milk. Immediately after foaling oestrogen and progesterone levels in the dam were 36 and 29% of preinjection means while the total corticoid levels remained relatively constant throughout the sampling period. The systemic levels of total oestrogens, progesterone and total corticoids immediately after birth were significantly (P less than 0.01) greater for the foal than the dam, and all declined in the foal throughout the 72-h sampling period. The levels of oestrogens and progesterone were greater (P less than 0.05) in the umbilical vein than umbilical artery, indicating the endocrine function of the placenta. However, total corticoids were greater in the umbilical artery than in the umbilical vein. The corticoid level in the jugular vein of the foal at birth was greater than that of the umbilical vein suggesting a fetal contribution to the total corticoid level.     

Plasma corticoids and brain tryptophan after acute and tolerance dosage of LSD.

The effect of acute and tolerance dosage schedules of LSD on plasma corticoids and brain tryptophan in normal, adrenalectomized and hypophysectomized rats was examined. Plasma corticoids increased 20-fold after one dose of LSD and the time course of this effect paralleled the increase in brain tryptophan. Both effects of LSD were abolished in adrenalectomized animals; after hypophysectomy the drug-induced tryptophan increase did occur but only after a significant delay. After multiple daily injections of LSD there was a significant degree of tolerance both to the plasma corticoid and brain trytophan response.     

Comparative analysis of gonadal and adrenal activity in the black and white rhinoceros in North America by noninvasive endocrine monitoring

Patterns of fecal reproductive steroid metabolites and adrenal corticoids were characterized for 12‐ to 24‐month periods in black (n = 10 male, 16 female) and white (n = 6 male, 13 female) rhinoceroses at 14 institutions. All black rhinoceros females exhibited at least some ovarian cyclicity on the basis of fecal progestogen analysis (range, 2–12 cycles/yr). However, cycles often were erratic, with many being shorter (<20 days; 18% of cycles) or longer (>32 days; 21%) than the average of 26.8 ± 0.5 days (n = 104 cycles). Five females exhibited periods of acyclicity of 2–10‐month duration that were unrelated to season. One complete and seven partial pregnancies were evaluated in the black rhinoceros. Fecal progestogens increased over luteal phase concentrations after 3 months of gestation. Females resumed cyclicity within 3 months postpartum, before calves were weaned (n = 5). Approximately half of white rhinoceros females (6 of 13) showed no evidence of ovarian cyclicity. Of the cycles observed, 5 were “short” (32.8 ± 1.2 days) and 24 were “long” (70.1 ± 1.6 days). Only two females cycled continuously throughout the study. One had both long (n = 9) and short (n = 2) cycles, whereas the other exhibited long cycles only (n = 5). Fecal estrogen excretion was variable, and profiles were not useful for characterizing follicular activity or diagnosing pregnancy in either species. Males of both species showed no evidence of seasonality on the basis of fecal androgen profiles. Androgen metabolite concentrations were higher (P < 0.05) in the black (27.6 ± 6.9 ng/g) than in the white (16.8 ± 3.1 ng/g) rhinoceros. An adrenocorticotropin hormone challenge in four black rhinoceros males demonstrated that the clearance rate of corticoid metabolites into feces was ～24 hours. Fecal corticoid concentrations did not differ between males and females, but overall means were higher in the black (41.8 ± 3.1 ng/g) than in the white (31.2 ± 1.7 ng/g) rhinoceros. In summary, fecal steroid analysis identified a number of differences in hormonal secretory dynamics between the black and white rhinoceros that may be related to differences in reproductive rates in captivity. Most black rhinoceros females exhibited some cyclic ovarian activity. In contrast, few white rhinoceroses demonstrated evidence of regular estrous cyclicity, and those females that were active had comparatively long cycles. Results also suggest that fecal corticoid concentrations reflect adrenal activity and may be species specific. Continued studies are needed to determine whether fecal corticoid measurements will be useful for understanding the cause of inconsistent gonadal activity in these two species. Because all but three (15.8%) of the white rhinoceroses evaluated in this study were less than 20 years of age compared to 73.1% (19 of 26) of the black rhinoceroses, the impact of age on reproductive and adrenal activity also needs to be evaluated further. Zoo Biol 20:463–486, 2001. © 2002 Wiley‐Liss, Inc.     

The short-term effect of cortisol, dexamethasone and ACTH administration on the serum levels of hexuronic acids and monosaccharides in man

The levels of serum monosaccharides (SMO) and hexuronic acids (SHA) were measured in subjects without any metabolic or endocrine disease after a short-time administration of cortisol, dexamethasone and ACTH. The effects of the three hormones were evaluated in regard to the urinary excretion of free cortisol and cortisone at basal conditions. In thirteen subjects a significant increase of SMO during cortisol treatment was registered after 24 hours. A distinct difference in the response of SMO to cortisol treatment was observed in patients with normal or increased cortisol excretion, respectively. In the subjects with high urinary free corticoids a peak of SMO occurred soon after 4 hours after cortisol administration, in the next 48 hours no tendency of return towards basal levels was observed. In the subjects with normal urinary free cortisol excretion only a slight increment was seen after 24 hours. Soon after 4 hours in eight subjects dexamethasone administration resulted in an increase of SMO without regard to the excretion of urinary free corticoids. The highest values were obtained after 28 hours of dexamethasone treatment. Ten hours after cessation of dexamethasone the levels of SMO reached the basal values. In the study in which ACTH was administered, an increment of SMO was registered only in the first four hours. In the group of subjects treated with ACTH a slight difference between subjects with normal and increased corticoid excretion was seen. The levels of SHA successively increased after the administration of all three hormones, without regard to the basal excretion of urinary free corticoids. This increase persisted also 10 hours after cessation of cortisol and dexamethasone, and 40 hours after the last dosis of ACTH, respectively. The possibility of an altered metabolism of glucose through the glucuronate pathway under conditions of glucocorticoid excess is discussed.     

Age-related differences in social grooming among adult female Japanese monkeys ( Macaca fuscata)

The present study investigated the influence of dominance rank in combination with kinship on age-related differences in social grooming among adult females in a free-ranging group of Japanese monkeys (Macaca fuscata). Eighty-three adult females were divided into six sub-groups according to age-class (younger: 5–9 years old; middle: 10–14 years old; older: 15–22 years old) and dominance rank (high and low rank). The ratio of the number of unrelated females that each female groomed to the total number of available unrelated females and grooming bouts which she gave to unrelated females decreased with increasing age for both high- and low-ranking females, whereas age did not appear to affect corresponding values for related females. On the other hand, compared with low-ranking females, high-ranking females of all age-classes received grooming more often from a larger number of unrelated females. Moreover, older females of low rank received grooming less often from a smaller number of unrelated females than younger females of low rank. These results indicate that with increasing age females are more likely to concentrate on related females when they have grooming interactions with other females. This tendency seems to be more apparent for low-ranking females. Moreover, the present findings also indicate that older high-ranking females could maintain their social attractiveness as high as younger high-ranking females.     

Reproduction in wild female olive baboons

The purpose of this paper is to evaluate several factors that influence female reproduction in a large troop of wild olive baboons (Papio cynocephalus anubis) based on 4 consecutive years of demographic data. Interbirth intervals were significantly shorter for females whose infants died before their next conception than for females whose infants survived. High-ranking mothers of surviving infants had significantly shorter birth intervals than comparable low-ranking mothers, independent of maternal age. This occurred mainly because the interval from resumption of cycling to conception was significantly shorter for high-vs. low-ranking females. Dominance rank did not influence sex ratio at birth, infant survival in the first 2 years, or adult female mortality. Age was also significantly related to interbirth intervals, with older females having shorter intervals. Primiparous females had consistently longer reproductive intervals than did multiparous females, but this difference reached statistical significance only for females whose infants died before the next conception. Primiparous females also experienced significantly higher infant mortality. Data on body size and estrous cycle length indicated no differences between high- and low-ranking females. Nutritional and stress-related mechanisms that may underlie the reproductive advantages of high rank are discussed.     

Effects of dibutyryladenosine 3',5'-monophosphate on steroid biosynthesis in humans

The effects of dibutyryladenosine 3', 5'-monophosphate (DBcAMP), a nucleotide analogue, on blood pressure, serum electrolytes and plasma corticoid concentrations were investigated in 10 normotensive healthy subjects who received a constant diet containing 5-8 g sodium chloride in hospital. The systolic blood pressure did not change after infusion of 0.25 or 0.33 mg/kg/min of DBcAMP for 20 min. On the other hand, the diastolic blood pressure was significantly decreased after the infusion of DBcAMP. The levels of serum sodium and potassium were significantly decreased after the infusion of DBcAMP. After infusion of 0.25 mg/kg/min of DBcAMP for 20 min, the changes in plasma levels of 6 corticoids [progesterone, deoxycorticosterone (DOC), 18-hydroxy-deoxycorticosterone (18-OH-DOC), corticosterone, cortisol and dehydroepiandrosterone sulfate (DHEA-S] revealed no significant changes. After infusion of 0.33 mg/kg/min of DBcAMP for 20 min, the plasma levels of cortisol, corticosterone and 18-OH-DOC were significantly increased and the changes in plasma levels of aldosterone showed a tendency to increase but this was not significant. The plasma levels of DOC and DHEA-S were not appreciably changed, while the plasma levels of progesterone were significantly decreased after the infusion of 0.33 mg/kg/min of DBcAMP. It is speculated therefore that DBcAMP may act to enhance the activity of the sodium-potassium pump and to promote steroid biosynthesis dose-dependently in humans.     

短尾猴和日本猴雄性性行为的比较研究

本文比较研究了短尾猴和日本猴的雄性性行为。短尾猴属单次爬跨射精型种类,每次交配平均持续23.2秒,日本猴属多次爬跨射精型种类,每次交配平均持续8.2分,交配期间雄性平均爬跨雌性lO.6次才能达到射精。短尾猴第1顺位雄性是群中的主要交配者,它占有交配总数的70.9 %;而日本猴第5顺位以下的雄性占交配总数的64%。交配中,两种猴雄性间相互打搅行为的发生频率大致相当。短尾猴高顺位雄性的打搅行为能使低顺位雄性的交配中断,但日本猴高顺位的打搅行为只能使低顺位雄性交配的54.3%中断。     

The effect of male tenure and female mate choice on paternity in free-ranging Japanese macaques

In this study, the paternity of all the infants born in 2002 and 2003 in a free-ranging Japanese macaque (Macaca fuscata) group at Arashiyama in Kyoto, Japan, was analyzed in relation to males' age, dominance rank, and tenure and females' mate choice. The fathers of 20 out of 23 infants were determined by DNA analyses. Central adult (high-ranking) males sired two infants, whereas peripheral adult (low-ranking) males sired 14 infants. Young males sired only one infant. Among adult males, tenure was the most dominant factor that negatively affected male reproductive success. The mating behavior of females who gave birth was also analyzed. The number of male copulations in the peri-fertilization period was positively correlated with the number of infants that they sired. Females copulated with central males with a long tenure only when fertilization was unlikely or impossible. The females probably avoided insemination by males with a long tenure and selected males with a shorter tenure as their mating partners during the ovulation period.     

Allogrooming Behavior and Grooming Site Preferences in Captive Bonobos (Pan paniscus): Association with Female Dominance

I tested the utility of Seyfarth's (1977) model of rank-related attractiveness to explain the distribution of allogrooming behavior among captive bonobos (Pan paniscus). Adult female bonobos generally have high social status and may be dominant over males. As predicted by the model, I found that high-ranking adult females received most allogrooming within each of the four investigated groups. Among adult female-adult female dyads, however, allogrooming was not clearly associated with dominance rank. Contradictory to predictions of the model, the highest-ranking females were responsible for most displacements over allogrooming, and grooming competition is positively correlated with dominance rank. In the second part of this study, I investigated the social significance of allogrooming body site preferences. Bonobos direct significantly most allogrooming to the face of conspecifics, and high- and low-ranking individuals, as well as males and females, differ significantly in their preferences for certain allogrooming sites. Subordinates and males tended to avoid facial grooming and preferred the back and anogenital region, while high-ranking individuals and females directed most allogrooming to the face and head of grooming partners. Data from this study support the hypothesis that high-ranking females are the most attractive grooming partners within a female-centered bonobo society. Many other aspects of allogrooming behavior, however, are not consistent with the model of rank-related attractiveness.     

The effects of polychlorinated biphenyls on plasma steroid levels and hepatic microsomal enzymes in fish

Aroclor 1254 was administered intraperitoneally (25 mg kg body wt⁻¹ in 1 ml of arachis oil) at weekly intervals for 4 weeks to trout and carp; arachis oil was used as the control. Activities of the following hepatic microsomal enzymes, aminopyrine demethylase, p-nitroreductase, UDP-glucuronyl-transferase and 1-leucyl-β-naphthylamide splitting enzyme were measured in both species; cytochrome P₄₅₀ and microsomal protein contents were also determined.
The changes in the levels of androgens, oestrogens and corticoid hormones were measured in the circulating blood of control and treated groups at weekly intervals. The blood was obtained by cardiac puncture.
Results indicated (a) a significant increase in the activities of all the enzymes measured except 1-leucyl-β-naphthylamide splitting enzyme, (b) cytochrome P₄₅₀ and microsomal protein contents were increased in trout, but not in carp, (c) a significant reduction in the plasma levels of androgens, oestrogens and corticoids in the treated groups, particularly at the end of the fourth week and (d) there was a correlation between increased enzyme activities and a decrease in plasma hormone levels.     

Hormonal patterns during heat stress following PGF(2)alpha-tham salt induced luteal regression in heifers

Ten, normally cycling, Holstein heifers were assigned to one of two environmental treatment groups (21.3 C, 59% RH or 32.0 C, 67% RH). PGF(2)alpha was used to induce luteal regression and synchronize estrus in order to evaluate temperature effects on various hormonal and physiological responses during the proestrous through metestrous periods. Environmental temperature (32.0 C) evoked a 1.4 C increase in rectal temperature and a 3.6 C increase in skin temperatures. Length of estrus was shorter (P<.10) for heifers at 32.0 C (16 vs 21 hr.). Average plasma progestin concentration between treatments was not different (P>.10). Mean estradiol concentrations were significantly (P<.10) lower in heifers at 32.0 C. No differences (P>.10) were detected in mean concentrations of LH between heifers at 21.3 C and 32.0 C. Preovulatory peak LH concentrations were 32.2 and 33.2 ng/ml plasma, respectively. All animals had a preovulatory surge of LH, suggesting that hyperthermia did not alter factors which regulate hypothalamic control of LH release. Mean basal concentrations of prolactin and corticoids were not different between temperature treatments (P>.10). However, mean corticoid response following ACTH was of lower magnitude, earlier to peak, and of shorter duration in heat stressed heifers. Heat stress did not appear to affect the hormonal milieu in peripheral plasma associated with corpus luteum regression (decrease in progestin) and ovulation (LH surge). However, duration of estrus, concentrations of estradiol at proestrus and corticoid response to injection of ACTH were reduced.     

Noninvasive monitoring of adrenocortical function in captive jaguars (Panthera onca)

Jaguars are threatened with extinction throughout their range. A sustainable captive population can serve as a hedge against extinction, but only if they are healthy and reproduce. Understanding how jaguars respond to stressors may help improve the captive environment and enhance their wellbeing. Thus, our objectives were to: (1) conduct an adrenocorticotrophic hormone (ACTH) challenge to validate a cortisol radioimmunoassay (RIA) for noninvasive monitoring of adrenocortical function in jaguars; (2) investigate the relationship between fecal corticoid (FCM) and androgen metabolite (FAM) concentrations in males during the ACTH challenge; and (3) establish a range of physiological concentrations of FCMs for the proposed protocol. Seven jaguars (3 M, 4 F) received 500 IU/animal of ACTH. Pre‐ and post‐ACTH fecal samples were assayed for corticoid (M and F) and androgen metabolites (M) by RIA. Concentrations of FCMs increased (P80.01) after ACTH injection (pre‐ACTH: 0.90 ± 0.12 µg/g dry feces; post‐ACTH: 2.55 ± 0.25 µg/g). Considering pre‐ and post‐ACTH samples, FCM concentrations were higher (P80.01) in males (2.15 ± 0.20 µg/g) than in females (1.30 ± 0.20 µg/g), but the magnitude of the response to ACTH was comparable (P>0.05) between genders. After ACTH injection, FAMs increased in two (of 3) males; in one male, FCMs and FAMs were positively correlated (0.60; P80.01). Excretion of FCMs was assessed in 16 jaguars (7 M, 9 F) and found to be highly variable (range, 80.11–1.56 µg/g). In conclusion, this study presents a cortisol RIA for monitoring adrenocortical function in jaguars noninvasively. Zoo Biol 31:426–441, 2012. © 2011 Wiley Periodicals, Inc.     

Benzoquinone levels as a function of age and gender of the red flour beetle, Tribolium castaneum

Liquid chromatography with both photodiode array and electrochemical detection was used to analyze as a function of age and gender the levels of two ρ-quinones, methyl-1,4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ), which are found in defensive secretions of the red flour beetle, Tribolium castaneum. We developed a method to simultaneously analyze quinones and hydroquinones excreted from or in homogenates of individual beetles. The major components present in beetle extracts were the benzoquinones and not free or conjugated forms of the hydroquinones. Greater than 95% of the quinone/hydroquinone mixture in extracts was present in the oxidized form. Because of their lability, however, the quinones were quantified indirectly as their hydroquinone derivatives after extraction in dilute acid supplemented with ascorbic acid as a reducing agent. Comparisons of whole body rinses and homogenates revealed that rinses recovered only up to 60% of the total quinones that were extracted after homogenization. The levels recovered also depended on the age and sex of the individual beetles sampled. ρ-Benzoquinones in both male and female beetles increased after adult eclosion and cuticle sclerotization for 40–50 days and then remained at their highest levels (15–21 μg MBQ and 22–32 μg EBQ per beetle) through 80 days posteclosion. Virgin females that were collected 40–80 days after eclosion contained approximately 40% more of these compounds than males of the same age. The build-up of ρ-benzoquinones subsequent to cuticle sclerotization apparently reflects the need for an adequate cuticular barrier for self-protection from these defensive compounds.