Purification and Radioimmunoassay of Chicken Growth Hormone

Harvey, Steven; Scanes, Colin G.

doi:10.1677/joe.0.0730321

Cited by 220 publications

(75 citation statements)

References 16 publications

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“…Following centrifugation and separation the plasma samples were stored at -20 °C prior to assay. Concentra tions of plasma GH were determined by an homologous radioim munoassay [13], in which the minimal detectable dose is 0.63 ng/ ml. All the samples were assayed together to avoid interassay varia tion.…”

Section: Methodsmentioning

confidence: 99%

Comparative Stimulation of Growth Hormone Secretion in Anaesthetized Chickens by Human Pancreatic Growth Hormone-Releasing Factor (hpGRF) and Thyrotrophin-Releasing Hormone (TRH)

Harvey¹,

Scanes²

1984

Neuroendocrinology

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Plasma concentrations of growth hormone (GH) were elevated in anaesthetized male domestic fowl following the intravenous administration of either synthetic human pancreatic GH-releasing factor 1–44 (NH2) (hpGRF) or synthetic thyrotrophin-releasing hormone (TRH). In 6-week-old chicks the plasma GH level was elevated between 5 and 10 min after the injection of hpGRF at doses between 1 and 80 µg/kg. The magnitude of the response increased with doses of hpGRF between 1 and 10 µg/kg but declined with higher doses. The GH concentration rapidly declined between 10 and 20 min and between 20 and 40 min after injection. The administration of TRH had similar effects on GH secretion, although the responses were greater than with comparable doses of hpGRF, and the most effective dose (1–1.4 µg/kg) was less than with hpGRF. In anaesthetized adult cockerels GH secretion was also increased by the administration of hpGRF (1–20 µg/kg) or TRH (0.1–80 µg/kg) and in both cases the dose-response relationship was biphasic. The maximal response to TRH in adult birds was again greater than that produced by hpGRF although the response was less than that elicited in immature birds and required a higher dose (20 µg/kg) of TRH. The optimal dose of hpGRF and the magnitude of the GH response induced in adult birds was comparable with that in immature chicks. These results demonstrate provocative effects of TRH and hpGRF on GH secretion in the domestic fowl. The sensitivity of the GH response to TRH suggests that it may have a physiological role in the hypothalamic control of GH secretion.

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Section: Methodsmentioning

confidence: 99%

Comparative Stimulation of Growth Hormone Secretion in Anaesthetized Chickens by Human Pancreatic Growth Hormone-Releasing Factor (hpGRF) and Thyrotrophin-Releasing Hormone (TRH)

Harvey¹,

Scanes²

1984

Neuroendocrinology

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“…The GH concentralions in the plasma samples were determined using a specific homologous radioimmunoassay for chicken GH (Harvey and Scanes, 1977). Each plasma was assayed in duplicate at two dilution.^ and all plasmas from each experiment were assayed together to eliminate inter-assay variation.…”

Section: Plasma Analysismentioning

confidence: 99%

CHANGES IN SOMATOMEDIN‐LIKE ACTIVITY AND GROWTH HORMONE CONCENTRATIONS IN THE PLASMA OF THE DOMESTIC FOWL (GALLUS DOMESTICUS)

Falconer

Harvey

Forbes

et al. 1981

Aust J Exp Biol Med

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Summary. Variations to immunoreactive growth hormone (GH) and bioassayable somatomedin-like activity (SLA) were determined in the plasma of the domestic fowl. The plasma concentralions of SLA (potency relative to a pooled serum standard) and GH were both inversely age-related in growing cockerels (Thornber 909) between 3 and 20 weeks of age (SLA, r = 0 454; P<0 01. GH. r = 0 548; P<0 01) and directly related to each other (r -0 54, P<0 01). In immature birds maintained on a photoperiod of 16 h light, 8 h darkness, plasma concentrations of SLA were highest during the first hour of darkness (I 19 ±: 0 18 units/ml (u/ml) mean ± S.E.M.. n = 6) and significantly lower 1 h after dawn (0 78 ± 0 07 u/ml n = 6). No diurnal variations in plasma concentralions of GH were observed. Deprivation of food in two strains of chickens (Thornber 909 and broiler) significantly reduced plasma concentrations of SLA in both strains and increased plasma concentrations of GH in the Thornber strain. Re-feeding fasted Thornber chickens caused the plasma concentrations of SLA and GH (o return to normal within 24 h but had no effect in broilers. Deprivation of water, which also reduces food intake, for 12. 18 and 24 h markedly reduced plasma concentrations of SLA but had no effect on plasma GH concentration in Thornber cockerels.

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“…were estimated using a specific radioimmunoassay for avian growth hormone [10] in which duck plasma cross-reacts.…”

Section: Plasma Immunoreactive Growth Hormone (Gh) Concentrationsmentioning

confidence: 99%

“…The results of this assay were expressed in terms of a standard preparation of chicken growth hormone, fraction DE 1 [10]. The minimum detectable concentration in the assay was 3.0 ng/ml.…”

Section: Plasma Immunoreactive Growth Hormone (Gh) Concentrationsmentioning

confidence: 99%

Somatostatin stimulates glucagon secretion in ducks

et al. 1980

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Summary.In normal fasting ducks, a somatostatin infusion (800ng/kg/min for 30min) elicited a prompt inhibition of insulin secretion, plasma levels falling from 140 _+ 20 to 20 + 6 pg Eq/ml as observed in mammals. -However plasma glucagon-likeimmunoreactivity shown to be decreased in mammals by somatostatin was sharply increased from a mean basal level of 1.46 + 0.13 ng Eq/ml to 6.61 + 0.77 ng Eq/ml. This effect was not mediated via inhibition of growth hormone secretion since it was also observed in hypophysectomised ducks. Despite the fall in plasma insulin and rise in GLI observed with somatostatin infusion in intact birds, plasma glucose concentrations were lower than with control saline infusion. [5,14,22] and it has been shown that somatostatin simultaneously inhibits insulin and glucagon secretion; moreover somatostatin appears to be one of the most effective A cell suppressants known [22]. Key words:In birds, it has been shown that the somatostatin producing D cells are particularly numerous in the islets of the pigeon pancreas [20] and very high somatostatin concentrations have been measured in the chicken pancreas [25]. As the duck appears to be an interesting species for studies on pancreatic hormone regulation [17,18] the present study was undertaken to explore the response of pancreatic hormones to somatostatin infusion in ducks. Materials and Methods AnimalsExperiments were performed on male Peking ducks 3 to 6 months old (2 to 2.5 kg), maintained on a normal diet with fowl pellets and tap water ad libitum. HypophysectomyRemoval of the pituitary was performed under local anaesthesia (1% xylocaine, Bellon) according to Benoit's technique [1]. These animals were used for experiments 4 to 10 days after operation. Completeness of hypophysectomy was checked by plasma growth hormone determination. InfusionsAfter an overnight fast the conscious ducks, normal or hypophysectomised, were tied to a board.Somatostatin was dissolved in 0.154 mol/l saline and administered intravenously as a bolus of 800 ng/kg immediately followed by a sustained infusion of 800 ng/kg/min for 30 minutes through a cathether inserted into a leg vein. As controls, normal or hypophysectomised ducks received 0.154 mol/1 saline infusions. Blood SamplingBlood samples were collected from a catheter inserted into a wing vein immediately before infusion (zero time) and at selected intervals thereafter.Blood samples kept on ice were centrifuged at 4 ~ and plasma stored at -20 ~ until the time of assay. Plasma DeterminationsPlasma glucose concentration was measured with a Technicon autoanalyser using a ferricyanide reagent [11] after dialysis of plasma.

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Purification and Radioimmunoassay of Chicken Growth Hormone

Cited by 220 publications

References 16 publications

Comparative Stimulation of Growth Hormone Secretion in Anaesthetized Chickens by Human Pancreatic Growth Hormone-Releasing Factor (hpGRF) and Thyrotrophin-Releasing Hormone (TRH)

Comparative Stimulation of Growth Hormone Secretion in Anaesthetized Chickens by Human Pancreatic Growth Hormone-Releasing Factor (hpGRF) and Thyrotrophin-Releasing Hormone (TRH)

CHANGES IN SOMATOMEDIN‐LIKE ACTIVITY AND GROWTH HORMONE CONCENTRATIONS IN THE PLASMA OF THE DOMESTIC FOWL (GALLUS DOMESTICUS)

Somatostatin stimulates glucagon secretion in ducks

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