Gonadotropic Hormones in the Urine of the Giraffe

Wilkinson, John F.; Fremery, P. De

doi:10.1038/146491a0

Cited by 10 publications

(3 citation statements)

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“…The existence in the giraffe of some change in the endocrine milieu during mid-pregnancy is also probable. This view is supported by the biochemical observations of Gombe and Kayanja (1974), particularly the rising levels of luteal progesterone in the second half of and by the much earlier unconfirmed report of Wilkinson and de Fremery (1940), of the presence in the urine of the pregnant giraffe of a gonadotrophin similar to that excreted by pregnant woman (HCG). This hormone was not detected on day 243 but positive indications of its presence were first obtained on day 322 and 337.…”

mentioning

confidence: 66%

Observations on Ovarian Structure and Development of the Southern Giraffe,Giraffa Camelopardalis Giraffa

Hall-Martin¹,

Rowlands

1980

South African Journal of Zoology

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The occurrence of vesicular follicles and corpora lutea (CL), without evidence of ovulation, in late fetuses and during prepubertal life was confirmed in the southern giraffe. In this, and other respects, the pattern of ovarian development is similar in the southern giraffe to the northern subspecies. This early ovarian activity recedes during late prepubertal life. Numerous accessory CL were present in pregnant and nonpregnant giraffe but they did not attain the size-of the true CL of pregnancy. The latter undergo an initial phase of rapid enlargement lasting about 100 days, followed by a period of recession till mid-pregnancy and a second growth phase which persists until term (457 days). The CL of pregnancy rapidly regresses after parturition. The accessory CL regress slowly and form normal looking corpora albicantia (CA). These CA are most abundant during early adult life as also are vesicular follicles.

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mentioning

confidence: 66%

Observations on Ovarian Structure and Development of the Southern Giraffe,Giraffa Camelopardalis Giraffa

Hall-Martin¹,

Rowlands

1980

South African Journal of Zoology

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“…The extent to which fetal gonadal hypertrophy and CL formation can be attributed to maternal gonadotrophins or to those of the fetus itself has remained problematical when ovarian luteinization does not persist after birth. The find¬ ing of urinary gonadotrophins in pregnant giraffe (Wilkinson & de Fremery, 1940) led Kellas et al (1958) to postulate that these gonadotrophins stimulated the development of the fetal CL. In the giraffe, Kayanja & Blankenship (1973) d 46 S. Gombe and E. I. .…”

Section: Introductionmentioning

confidence: 97%

Ovarian Progestins in Masai Giraffe (Giraffa Camelopardalis)

Gombe¹,

Kayanja²

1974

Reproduction

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Gonadal progestins from fetal, juvenile, pregnant and non\x=req-\ pregnant Masai giraffe (Giraffa camelopardalis) were extracted, purified by TLC and measured by GLC or by competitive protein-binding assay. Progesterone was found in fetal ovaries and in a fibrotic CL from a nearterm fetus as well as in CL from juvenile animals. In pregnant animals, luteal progesterone probably increased with the duration of gestation.The values of 20\g=b\-hydroxyprogesterone were higher in juvenile giraffes than in the fetus or during early pregnancy. No 20\g=b\-hydroxyprogesterone was detectable in a CL from late pregnancy or a CL from a non-pregnant giraffe. The values tended to be inversely related to the progesterone levels.Detectable levels of 17\g=a\-hydroxyprogesterone were present in the fetal ovary, juvenile CL and in one pregnant animal with an early preimplantation blastocyst. In the later stages of gestation, the hormone levels were too low to be detected by TLC. Thus, it seems that the CL present in the ovaries of fetal and juvenile giraffes are endocrinologically active and similar in function to the CL of adult female giraffes.

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“…The modifications in the gonads of the foetal giraffe differ from those just described, for whereas the enlargement of the gonads of the aforementioned species can be ascribed almost entirely to the proliferation of the interstitial cells; the changes in the giraffe ovary are due to extensive and widespread follicular development and luteinization (Amoroso, 19557;Amoroso & Finn, 1962). Whether these changes reflect a genuine development of ovarian sensitivity to the gonad stimulating substances which appear in the urine of the pregnant giraffe (Wilkinson & de Fremery, 1940), or may be referred to some other cause, is not yet clear. At any rate, it would appear that the ovary, as judged by its histological appearance, is capable of adult secretory and gametogenic activity long before it is normally called upon to exercise these functions.…”

Section: The Prostatementioning

confidence: 99%

Reproductive and endocrine organs of foetal, newborn and adult seals

Amoroso

Bourne

Harrison

et al. 1965

Proceedings of the Zoological Society of London

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During late foetal life and at birth the gonads of both Grey and Common seals are enlarged, and there are indications of stimulation in the rest of the reproductive tract. The enlargement of the gonads is due mainly to the presence of very large numbers of cells resembling interstitial cells. The presence of groups of small round cells resembling lymphocytes and of cells intermediate between them and fully developed interstitial cells suggests that the small round cells may be the precursors of the latter. Whether these cells are lymphocytes or primitive mesenchymal cells cannot be stated with certainty. The ovaries of foetal Common and Grey seals contain no follicles beyond the stage where oocytes are ensheathed in a single layer of epithelial cells, but more marked follicular development was present in the ovaries of a still‐born Californian sea lion. No evidence of spermatogenesis was seen in the testes of any foetal or neonatal male seal. Regression occurs rapidly after birth and is nearly complete at the age of two weeks. The interstitial cells disappear by a process similar to fatty degeneration. Retrogression is accompanied by a remarkable obliteration of many blood vessels supplying the outer part of the medulla and the cortex of the ovary. The stimulus responsible for the precocious enlargement of the foetal gonads is removed with the birth of the young. The rapid decrease of endocrine influence after birth suggests that the placenta may be implicated. In the adult Common and Grey seal the corpus luteum persists until the end of pregnancy and begins to degenerate a few days after parturition. Follicular development occurs in the maternal ovaries towards the end of pregnancy and in the immediate post‐parturient period. The maternal ovaries are probably a source of oestrogens, both before, during, and after parturition, and such oestrogens could cross the placenta and affect foetal tissues. The prostate of all male foetuses of both species towards the end of pregnancy and immediately after birth is markedly enlarged. There is proliferation and hypertrophy of the prostatic alveoli, dilation of the tubules, and an increase in the size of the epithelial cells. A week after birth the weight of the gland is reduced by more than one‐half. Persistence and hyperplasia of the uterus masculinus occurs in some foetal and newborn pups of the Common seal, but no similar enlargement was seen in the Grey seal. The thyroid in the late foetal and neonatal Common and Grey seals showed wide differences in their histological appearances. The thyroid glands from an adult lactating seal of each species were widely different. In the Grey seal it was almost completely atropic but in the Common seal it appeared to be intensely active. The amount of medulla present in the adrenal of foetal seals is small by comparison with that of the cortex. A large number of cortical islands packed with lipid is present in the medulla, often containing more lipid than the cortex itself. The capsule of the adrenal varies considerably in thickness ...

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Gonadotropic Hormones in the Urine of the Giraffe

Cited by 10 publications

References 0 publications

Observations on Ovarian Structure and Development of the Southern Giraffe,Giraffa Camelopardalis Giraffa

Observations on Ovarian Structure and Development of the Southern Giraffe,Giraffa Camelopardalis Giraffa

Ovarian Progestins in Masai Giraffe (Giraffa Camelopardalis)

Reproductive and endocrine organs of foetal, newborn and adult seals

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