Ovarian Progestins in Masai Giraffe (Giraffa Camelopardalis)

Gombe, S.; Kayanja, F. I. B.

doi:10.1530/jrf.0.0400045

Cited by 10 publications

(9 citation statements)

References 7 publications

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“…Despite this regression, we found that fP4 levels were maintained or even rose until late pregnancy. These findings are in agreement with observations by earlier researchers [15,16,41]. Therefore, an extraovarian P4 origin (probably the placenta), similar to that found in the cow, ewe, and mare [15,42], is likely.…”

Section: Discussionsupporting

confidence: 93%

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Hildebrandt

Pootoolal²,

Rich³

et al. 2009

Biology of Reproduction

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Fecal and urinary progestin analyses have shown that giraffes express a short reproductive cycle, averaging 15 days, compared with other large ruminants. However, actual ovarian events have not been correlated with the hormonal pattern. In this study, mature cycling female Rothschild giraffes (Giraffa camelopardalis rothschildi) were repeatedly examined by transrectal ultrasonography to correlate ovarian function with changes in fecal progestin (fP4 [n(c) = 6]) and estradiol (fE2 [n(c) = 6]) and serum progestin (n(c) = 2) as measured by enzyme immunoassay. Five females became pregnant and were monitored during early gestation. In this study, we discovered that hormone values for fP4 in cycling giraffes do not correlate with the classic profile of follicular development, ovulation, and luteogenesis. The corpus luteum (CL) and the next dominant follicle were forming simultaneously. A mean +/- SD peak in fE2 of 254.92 +/- 194.76 ng/g and subsequent ovulation occurred as early as 1 day after the fall in fP4. In pregnant giraffes, the CL reached a diameter significantly larger (mean +/- SD, 41.02 +/- 2.70 mm; P = 0.0126) than that during the cycle (33.48 +/- 2.80 mm), while follicular activity and fluctuating fE2 were still present. With this research, we demonstrated that the progesterone profile typically used to characterize the ovarian cycle does not correlate with luteal development in the ovaries of this species. Furthermore, we conclude that the giraffe could have evolved a short reproductive cycle because of the almost parallel order of ovarian events.

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Section: Discussionsupporting

confidence: 93%

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Hildebrandt

Pootoolal²,

Rich³

et al. 2009

Biology of Reproduction

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“…A previous report demonstrated that progestins were present in the extracts of homogenised giraffe ovarian tissue, both maternal and fetal (Gombe & Kayanja 1974). The immunohistochemical demonstration in this study of 3b-HSD, the enzyme required to convert pregnenolone to progestagens in the steroidogenic pathway, in the granulosa cells of developing follicles and luteal cells of both the maternal and the fetal ovaries highlighted the ability of these tissues to synthesise progestagens.…”

Section: Discussionsupporting

confidence: 68%

“…The presence of these luteal structures in the fetal ovary was subsequently confirmed by Kayanja & Blankenship (1973), Gombe & Kayanja (1974) and Skinner & Hall-Martin (1975) and, more recently, Benirschke (2007) also noted multiple, small CL-like structures in the ovaries of an aborted giraffe fetus and a 3-day-old neonate. Such unusual developments in the fetal ovaries has led to speculation that the multiple CL-like structures may play a role in pregnancy maintenance, although the persistence of follicular growth and luteinisation after birth in the pre-pubertal giraffe (Kellas et al 1958, Kayanja & Blankenship 1973, Gombe & Kayanja 1974, Hall-Martin & Rowlands 1980, Lueders et al 2009a would seem to argue against such a possibility. Interestingly, the newborn Okapi (Okapia johnstoni), the only other living giraffid species, does not display the same ovarian activity as the giraffe neonate (Bernirschke 2007).…”

Section: Introductionmentioning

confidence: 80%

“…Progestins have been isolated from the ovaries of fetal, juvenile, pregnant and non-pregnant giraffe (Gombe & Kayanja 1974), and it was originally postulated that a placental gonadotrophin might be responsible for the follicular activity and luteinisation seen in the fetus (Kellas et al 1958) following a report of gonadotrophic hormones in the urine of a pregnant giraffe by Wilkinson & De Fremmery (1940). However, Hall-Martin & Rowlands (1980) were unable to find any gonadotrophic activity in giraffe placental tissue and the continuation of follicular and luteal development in pre-pubertal giraffe ovaries also argues against involvement of a placental gonadotrophin (Gombe & Kayanja 1974, Lueders et al 2009a. Although the adrenal gland of the giraffe fetus has not been investigated endocrinologically, Benirschke (2007) mentioned that it is unusually large and has a remarkably wide zona fasciculata.…”

Section: Introductionmentioning

confidence: 99%

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Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis)

Wilsher¹,

Stansfield

Greenwood

et al. 2013

Reproduction

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Gross, histological and immunocytochemical examinations carried out on maternal and fetal reproductive tissues from two pregnant giraffes at an estimated 8 and 13.5 months of gestation (termZ15 months) revealed a typically ruminant macrocotyledonary placenta with binucleate trophoblast cells scattered sparsely in the placentome where they stained intensely with a prolactin antiserum. Binucleate cells were present in greater numbers in the intercotyledonary allantochorion where they did not stain for prolactin whereas the uninucleate trophoblast still did. A single large corpus luteum of pregnancy and several small luteinised follicles were present in the maternal ovaries while the fetal ovaries at 13.5 months gestation showed an assortment of enlarging antral follicles and partially and completely lutenised follicles, the granulosa and luteal cells of which stained positively for 3b-hydroxysteroid dehydrogenase (3b-HSD), 17,20 lyase, prolactin, progesterone receptor and androgen receptor, but negatively for aromatase. The uninucleate trophoblast of the placentome and intercotyledonary allantochorion, the epithelium of the maternal endometrial glands, the seminiferous epithelium in the fetal testis at 8 months of gestation and the zonae fasciculata and reticularis of the fetal adrenal at 13.5 months also stained positively for 3b-HSD and negatively for aromatase. Endocrinologically, it appears that the giraffe placenta is more similar to that of the sheep than the cow with a placental lactogen as the likely driver of the considerable degree of luteinisation seen in both the maternal and the fetal ovaries.

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“…Information on the reproductive performance of the giraffe is limited [6][7][8][9]. Recently, del Castillo et al [10] measured fecal pregnane concentrations during pregnancy and the postpartum period and found them to be high during pregnancy, especially during the last third of pregnancy.…”

mentioning

confidence: 99%

Fecal Progestagen and Estrone During Pregnancy in a Giraffe: A Case Report

Isobe

Nakao

Shimada

et al. 2007

Journal of Reproduction and Development

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Abstract. The present study was carried out to measure fecal progestagen and estrone concentrations during pregnancy in a giraffe and examine the possibility of utilizing this assay system for pregnancy diagnosis. Fecal samples were collected from a giraffe during her third and fourth parities and mixed with methanol to prepare a fecal solution. Diluted fecal solution was used for direct enzyme immunoassay for progestagen and estrone. The newborn calf from the third parity was viable, although that from the fourth parity died 5 days after calving. In the third parity, the giraffe's progestagen and estrone concentrations increased transiently from days 30 to 120 of pregnancy. Then, they decreased and remained low until day 330. This was followed by a drastic rise in both concentrations as parturition approached. Parturition caused a reduction in the progestagen and estrone concentrations of the feces. In the fourth parity, the progestagen concentration increased gradually after mating until day 320. This was followed by a reduction in the concentration until parturition. However, the estrone concentration fluctuated, and the duration and extent of the prepartum rise in concentration were shorter and lower than those of the third parity. The hormone dynamics of the third parity suggest the possibility of early pregnancy diagnosis by measuring progestagen or estrone between days 30 and 120 after mating.

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Ovarian Progestins in Masai Giraffe (Giraffa Camelopardalis)

Cited by 10 publications

References 7 publications

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Ovarian Ultrasonography Correlated with Fecal Progestins and Estradiol During the Estrous Cycle and Early Pregnancy in Giraffes (Giraffa camelopardalis rothschildi)1

Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis)

Fecal Progestagen and Estrone During Pregnancy in a Giraffe: A Case Report

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