Direct measurements of urinary estrone conjugates during the normal menstrual cycle of the gorilla (<i>Gorilla gorilla</i>)

Czekala, Nancy M.; Mitchell, W. R.; Lasley, Bill L.

doi:10.1002/ajp.1350120210

Cited by 13 publications

(8 citation statements)

References 12 publications

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“…However, the comparison of our hormonal findings in the free-ranging mountain gorilla to the captive lowland gorilla suggests some differences in hormonal excretion. The peak EC concentration of the mountain gorilla in the one conception cycle (Pp) was elevated above either the conceptive or nonconceptive cycles of the captive lowland gorillas [Czekala et al, 1987]. The PDG profile of the captive lowland gorilla also differs from the mountain gorilla.…”

Section: Discussionmentioning

confidence: 99%

Reproductive monitoring of free-ranging female mountain gorillas by urinary hormone analysis

Czekala

Sicotte

2000

Am. J. Primatol.

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Frequent urine samples from three habituated free‐ranging adult female mountain gorillas were collected during a four‐week period in order to characterize, by analysis of urinary hormones, their ovarian cycle, and to diagnose pregnancy. A conceptive cycle and two cycles that did not result in full term pregnancy were monitored. Behavioral and physiological observations of mating and labial swellings were correlated to urinary hormone results. Mating occurred on days with elevated estrogens. Labial swelling was maximum near or at peak estrogen levels. Pregnancy was diagnosed at the field site by measurement of chorionic gonadotropin using commercially available human pregnancy detection kits. In one pregnancy, gestation length was 254 days. The pregnanediol glucuronide concentrations of the mountain gorilla did not change during the nonconceptive cycle. During the conceptive cycle, the concentrations did not increase until the approximate time of implantation. This finding suggests marked differences in steroid production or metabolism between the mountain gorilla and the captive lowland gorilla. Am. J. Primatol. 51:209–215, 2000. © 2000 Wiley‐Liss, Inc.

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Section: Discussionmentioning

confidence: 99%

Reproductive monitoring of free-ranging female mountain gorillas by urinary hormone analysis

Czekala

Sicotte

2000

Am. J. Primatol.

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“…I analyzed samples for urinary E1C samples using RIA, following Shideler et al [1983], Czekala et al [1987Czekala et al [ , 1991, and Ellison [1988]. For samples that had been eluted in methanol, ethanol, ether, and acetylnitrile, and dried down, aliquots of 0.1 ml of sample reconstituted in 2 ml of Tris buffer (thus equivalent to 0.01 ml of undiluted urine) were combined with 0.3 ml of Tris assay buffer.…”

Section: Ria Methodologymentioning

confidence: 99%

“…I tested the ability of filter paper to retain Cr after drying, and the ability of methanol to serve as an effective solvent, using procedures modified from those described by Czekala et al [1987Czekala et al [ , 1991 and Shideler et al [1983]. Shideler et al [1995] used hole punches to sample pieces of urine-soaked filter paper disks.…”

Section: Creatinine (Cr) Validationmentioning

confidence: 99%

Radioimmunoassay of estrone conjugates from urine dried on filter paper

Knott

2005

American J Primatol

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Hormonal analysis of urine from free-ranging primates has been limited due to the difficulty of preserving samples under field conditions. Drying urine on filter paper is an alternative for field preservation. This study describes a new laboratory method for eluting steroids from filter paper with methanol, along with a series of experiments used to develop and validate this method. The overall elution recovery of estrone sulfate (ES) from filter paper was 86.4%. Estrone conjugate (E1C) levels in humans and captive orangutans were analyzed by radioimmunoassay (RIA). Values from samples dried on filter paper were significantly correlated with values from matched frozen samples, with elution efficiencies ranging between 97.1% and 102.4%. Creatinine (Cr) measurements from frozen urine compared to urine dried on filter paper were also significantly correlated (r=0.96) with an elution efficiency of 101.7%. After the samples were stored for 2 years, the absolute values of E1C and Cr were significantly lower but were still significantly correlated with frozen urine values. These data demonstrate the effectiveness of filter paper as a medium for preserving urinary steroid samples, and the efficiency of methanol as a solvent for eluting E1C and Cr. This method thus provides a viable alternative to the traditional procedure of freezing urine for field studies, where freezers are not available.

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“…Where daily urine collection is possible, ovulation test kits, i.e., dipsticks that detect the high levels of luteinizing hormone characteristic of impending ovulation, such as the Ovuquick test (Quidel, San Diego, CA), can reliably indicate reproductive status and timing of ovulation in apes (Czekala et al 1987;Knott 1996;Stumpf and Boesch 2005). One can also derive ovulation time from hormonal profiles through measuring ovarian hormones (estrogen and progesterone) or their metabolites noninvasively via urine or feces (Emery Thompson 2005;Fox 1998;Knott 1998Knott , 2005.…”

Section: Determining Reproductive Phasementioning

confidence: 99%

A Comparison of Female Mating Strategies in Pan troglodytes and Pongo spp.

2008

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Orangutans and chimpanzees differ in many aspects of their mating and social systems. Nevertheless, because both great apes require enormous maternal investment in offspring and because female reproductive potential is limited, female orangutans and chimpanzees should be selective of their mates, yet expected to exhibit anti-infanticide strategies such as mating with multiple males. We review and compare mating patterns in orangutans and chimpanzees to understand how these critical pressures are filtered through the different demands of the socioecology of each species. We highlight the variation in female mating behavior as a function of the proximity of ovulation. We conclude that both genera pursue tactics for paternity confusion by mating with multiple males and by mating cooperatively or even proceptively with nonpreferred partners when conception is unlikely. Mating selectivity is suggested by variation in proceptive behavior toward particular partners and by increased resistance of nonpreferred partners during the periovulatory period. Thus, data for both species support a mixed mating strategy whereby females shift their mating behavior in accordance with ovulatory status to accommodate the competing demands of mate selectivity and paternity confusion.

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

Cited by 13 publications

References 12 publications

Reproductive monitoring of free-ranging female mountain gorillas by urinary hormone analysis

Reproductive monitoring of free-ranging female mountain gorillas by urinary hormone analysis

Radioimmunoassay of estrone conjugates from urine dried on filter paper

A Comparison of Female Mating Strategies in Pan troglodytes and Pongo spp.

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