High Gonadotropic Hormone Concentration in Pregnant Ponies

Cole, H. H.

doi:10.3181/00379727-38-9788p

Cited by 11 publications

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“…Cole (1938) noted an inverse relationship between the size of the mare and the maximum concentration of PMSG in the serum, and he found that a fourfold difference could exist between small ponies and larger breeds of horses.…”

Section: Resultsmentioning

confidence: 99%

The Immunological Measurement of Pregnant Mare Serum Gonadotrophin

Allen¹

1969

Journal of Endocrinology

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A quantitative haemagglutination\p=m-\inhibition assay was used to measure pregnant mare serum gonadotrophin (PMSG) concentration in six Welsh Mountain pony mares and ten thoroughbred mares during early pregnancy. In both groups of animals PMSG was first detected in the serum between 35 and 41 days of gestation, the limit of sensitivity of the assay being 0\m=.\6i.u. PMSG/ml. The levels rose sharply to reach a maximum at 55\p=n-\60 days of gestation in the ponies and 60\p=n-\65 days in the thoroughbreds. The highest concentrations recorded in both groups were 100\p=n-\112 i.u. PMSG/ml., although one animal never produced more than 11 i.u./ml. The highest concentrations were found in the primiparous ponies. The rate of decline of the PMSG concentrations was not as great as the initial rate of increase, and in all animals PMSG had virtually disappeared from the serum by 120\p=n-\130 days of gestation.The haemagglutination-inhibition assay was evaluated as a pregnancy diagnosis test; 183 sera from 58 mares of various breeds between 41 and 87 days of gestation all gave a positive result, whereas 47 sera from non\x=req-\ pregnant mares, geldings and stallions gave uniformly negative results. An additional 64 sera from 23 mares between 88 and 110 days of gestation gave 62 positives, the two negative reactions being in a pony mare that showed exceptionally low concentrations of PMSG throughout pregnancy.

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Section: Resultsmentioning

confidence: 99%

The Immunological Measurement of Pregnant Mare Serum Gonadotrophin

Allen¹

1969

Journal of Endocrinology

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“…Previous studies (Cole, 1938) have indicated that the concentration of gonadotrophin in pregnant mare serum varies inversely with the size of the mare. In ponies the concentration may be 8 times that found in mares of the draft breeds.…”

Section: Discussionmentioning

confidence: 96%

“…The decline, they concluded, could not be explained on the basis of age, parity or nutritional status. One of us 248 M. T. Clegg, H. H. Cole, C. B. Howard and H. Pigon (Cole, 1938) likewise expressed the view that gonadotrophin secretion was not in¬ fluenced by dietary deficiencies. Nevertheless, we have encountered some very low titres during pregnancy in the blood of emaciated range mares and suggest that this question needs further study.…”

Section: Discussionmentioning

confidence: 99%

The Influence of Foetal Genotype on Equine Gonadotrophin Secretion

Clegg¹,

Cole²,

Howard³

et al. 1962

Journal of Endocrinology

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The serum concentration of gonadotrophin during several stages of pregnancy was determined in seven mares bred to a stallion and in four mares bred to a jack. To eliminate individual differences, two mares were bred successively to a stallion and to a jack. When the mare is carrying a mule foetus the hormone concentration is approximately one-tenth that associated with a horse foetus. One mare carrying a mule foetus was killed on the 69th day of pregnancy. Though the endometrial cups appeared normal histologically, the endometrial cup secretion was scanty and low in potency.The amount of hormone in the cups themselves was also low.The genotype of the foetus, we conclude, influences the secretory activity of the endometrial cups.

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“…Many factors have been shown to influence eCG concentrations in mares’ blood, including mare size (8,60,61), mare parity (62), paternity of the conceptus (63), twin pregnancy (64), and conception at the first postpartum oestrus (65). More recent experiments, in which mare size, age, parity, and conceptus paternity were standardized, have also shown that both body condition and exercise have a significant influence on eCG concentrations in maternal blood(66).…”

Section: Physiology Of Invasive Trophoblast In the Horsementioning

confidence: 99%

The Equine Endometrial Cup Reaction: A Fetomaternal Signal of Significance

Antczak

Mestre

Wilsher³

et al. 2013

Annu. Rev. Anim. Biosci.

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A remarkable feature of equine pregnancy is the development of the invasive trophoblast of the chorionic girdle and its formation of the gonadotrophin-secreting endometrial cup cells in early gestation. The details of this process have been revealed only slowly over the past century, since the first description of the endometrial cups in 1912. This centennial presents an opportunity to review the characteristics of the cells and molecules involved in this early, critical phase of placentation in the mare. The invasiveness of the chorionic girdle trophoblast appears to represent an atavistic attribute more commonly associated with the hemochorial placentae of primates and rodents but not with the more recently derived epitheliochorial placentae of the odd-toed ungulates. The nature of and raison d’etre for the strong fetal signals transmitted to the mare by the endometrial cup reaction, and her responses to these messages, are the subject of the present review.

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High Gonadotropic Hormone Concentration in Pregnant Ponies

Cited by 11 publications

References 0 publications

The Immunological Measurement of Pregnant Mare Serum Gonadotrophin

The Immunological Measurement of Pregnant Mare Serum Gonadotrophin

The Influence of Foetal Genotype on Equine Gonadotrophin Secretion

The Equine Endometrial Cup Reaction: A Fetomaternal Signal of Significance

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