Cross-Reaction in Radioimmunoassay Between Human Chorionic Gonadotrophin and Plasma From Various Species

Kd, Bagshawe; Ah, Orr; Godden, J.

doi:10.1677/joe.0.0420513

Cited by 13 publications

(2 citation statements)

References 9 publications

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“…The amount of radioactivity in the filtrate is inversely related to the amount of HCG or LH in the samples; 100% recovery of isotopic HCG=O L H or HCG in sample. The dose response curves of HCG and avian L H are parallel (Bagshawe, Orr & Godden 1968) so that theoretically the actual quantity of LH per ml of plasma can be assessed (it can of course be assumed that avian material contains no HCG). Nonetheless, it has been deemed desirable to present the results on a comparative percentage basis.…”

Section: Methodsmentioning

confidence: 99%

The Significance of Circadian Based Photosensitivity in the House Sparrow Passer Domesticus

Murton

Lofts

Orr

1970

Ibis

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Summary Adult male House Sparrows, wild caught in December and January, were held on daily seven‐hour artificial photoperiods for 14 days beginning in late February, with the aviary lights arranged to switch‐on at 07.00 hrs. A control sample was then killed and the remaining birds divided into groups which received six hours of light daily (beginning at 07.00 hrs) plus one further hour of light given at variable times from the dawn. A further group received 16 hours of light given continuously (16L‐8D). Pooled plasma samples from these groups were assayed for luteinizing hormone (using a radio‐immunoassay technique) and the histological condition of all testes was examined. Although all subjects received the same total amount of photostimulation only those given schedules simulating long days responded with testicular growth and spermatogenesis. It is argued that this was because light can only be effective if received during relatively restricted phases of a circadian‐based rhythm; only during these phases is the neuroendocrine apparatus sensitised to photostimulation. Increase in size of the testis tubules and meiotic divisions of primary spermatocytes, leading to secondary spermatocyte production and increase in testis weight, were considered to be indicators of FSH activity. Using these criteria a curve of FSH activity could be drawn and be compared with the quantitative curve for LH levels obtained from the plasma assays (a comparable assay technique for FSH is not yet available). Although LH levels remained approximately the same in all groups, and this correlated with the histological and histochemical evidence, FSH activity was more pronounced in those groups given light flashes at increased intervals after the beginning of the dark period. Thus LH activity occurred in the absence of spermatogenetic development in those groups given “short‐day” schedules. Birds kept on a 16L‐8D regime contained less plasma LH than anticipated and the possible existence of inhibitory mechanisms is discussed. It is feasible that when much FSH secretion begins LH production declines, but this explanation is speculative. The temporal pattern of LH production was markedly different in Greenfinches (for which the experimental results are described elsewhere) than in the House Sparrows, and the discussion considers the reasons for these differences in terms of the ecological and ethological adaptations of the two species.

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Section: Methodsmentioning

confidence: 99%

The Significance of Circadian Based Photosensitivity in the House Sparrow Passer Domesticus

Murton

Lofts

Orr

1970

Ibis

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“…All these results make more interesting the results of Bagshawe, Orr & Godden (1968) who, using anti-HCG and HCG labelled with 125I, observed a cross-reaction with plasma from laying hens. This cross-reaction was used to estimate circulating levels of ' …”

Section: A)mentioning

confidence: 65%

A Radioimmunoassay for Avian Luteinizing Hormone

Follett¹,

Scanes²,

Cunningham³

1972

Journal of Endocrinology

565

195

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SUMMARYA radioimmunoassay for avian luteinizing hormone (LH) is described, using antisera raised against chicken pituitary gonadotrophins of varying degrees of purity, and purified chicken LH for radio-iodination. A postprecipitation double antibody method was developed with a sensitivity to 30-60 pg of purified chicken LH.The specificity of the method was investigated. Fractions of follicle-stimulating hormone with high biological activity showed little immunological activity, whilst all the fractions of LH tested showed strong immunological potency. Human, ovine and bovine LH showed virtually no cross-reaction.The method measures immunoreactive LH in 25-200\g=m\lplasma from chickens and quail. The plasma levels correlate well with known physiological processes, being absent in hypophysectomized birds and low in sexually immature quail. When testicular growth begins in quail the level rises eightfold; castration increases it still further while the level is lowered by testosterone. Manipulation of the pituitary-thyroid system in quail did not significantly affect the level of plasma activity.Estimates of activity are independent of either the antiserum or the iodinated preparation of LH used in the assay.The antisera used all blocked gonadotrophic activity in vivo.

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Reproductive Physiology and Behavior Interactions in Nonmammalian Vertebrates

Crews

Silver

1985

Reproduction

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Cross-Reaction in Radioimmunoassay Between Human Chorionic Gonadotrophin and Plasma From Various Species

Cited by 13 publications

References 9 publications

The Significance of Circadian Based Photosensitivity in the House Sparrow Passer Domesticus

The Significance of Circadian Based Photosensitivity in the House Sparrow Passer Domesticus

A Radioimmunoassay for Avian Luteinizing Hormone

Reproductive Physiology and Behavior Interactions in Nonmammalian Vertebrates

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