Turkey Prolactin: Purification by Isotachophoresis and Partial Characterization

Proudman, J. A.; Corcoran, David

doi:10.1095/biolreprod25.2.375

Cited by 25 publications

(5 citation statements)

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“…The crop sac bioassay potency of this prep¬ aration could not be estimated due to non-parallelism with the oPRL standard (Proudman & Corcoran, 1981); however, it exhibited approximately one-third the activity of oPRL in a chicken kidney radiorecep¬ tor assay for prolactin (J. Proudman, unpublished data). In contrast, this same preparation was 15 times less effective than oPRL in competing with 125I-labelled oPRL in binding to dove forebrain mem¬ branes (Buntin & Ruzycki, 1987).…”

Section: Discussionmentioning

confidence: 99%

Reductions in plasma LH concentration and testicular weight in ring doves following intracranial injection of prolactin or growth hormone

Buntin

Lea²,

Figge³

1988

Journal of Endocrinology

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Testicular weights and concentrations of LH in plasma were measured in individually housed adult male ring doves given five daily intracerebroventricular injections of saline-NaHCO3 vehicle (2 microliter), ovine prolactin (0.1, 0.5, 1.0 or 2.0 micrograms/day), turkey prolactin (1.0 micrograms/day), turkey GH (1.0 micrograms/day) or ovine GH (1.0 micrograms/day). Administration of ovine prolactin resulted in a dose-dependent suppression of plasma LH concentration, with values in the two highest dose groups averaging three- to fivefold less than those of vehicle-injected controls. Reductions of similar magnitude were obtained following intracranial administration of turkey, ovine or human GH. Whilst effective in reducing plasma LH, turkey prolactin was less effective than an equivalent dose of ovine prolactin. Testicular regression was observed in all treatment groups which showed a significant decrease in plasma LH concentrations. Because crop sacs remained undeveloped in all treatment groups, it was concluded that these centrally administered hormones acted primarily at the level of the brain or pituitary to exert their suppressive effects. The possibility that prolactin and GH interact with different binding sites to inhibit LH secretion is discussed, together with evidence for a possible role of prolactin and GH in gonadotrophin regulation under normal physiological conditions.

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Section: Discussionmentioning

confidence: 99%

Reductions in plasma LH concentration and testicular weight in ring doves following intracranial injection of prolactin or growth hormone

Buntin

Lea²,

Figge³

1988

Journal of Endocrinology

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“…Plasma samples were stored at -20°C until assayed. Plasma concentrations of PRL were measured by the radioimmunoassay method using turkey PRL antigen (Proudman & Corcoran, 1981) and turkey PRL antibody (Burke & Papkoff, 1980). Concentrations of LH and oestradiol in plasma were measured by the radioimmunoassay methods of Hattori & Wakabayashi (1979) for LH and that of Kono et ai (1981) for oestradiol.…”

Section: Assaysmentioning

confidence: 99%

Effects of removal of chicks from hens on concentrations of prolactin, luteinizing hormone and oestradiol in plasma of brooding Gifujidori hens

Kuwayama¹,

Shimada²,

Saito³

et al. 1992

Reproduction

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Gifujidori hens were allowed to repeat a breeding cycle in one season. In the first breeding cycle the duration of the brooding (raising chicks) stage was limited to 3 weeks, whereas in the second breeding cycle it was limited to 1 week by removing all chicks from mother hens. In the first breeding cycle, plasma prolactin (PRL) was high during the incubation period, but rapidly decreased on the day of hatching and reached minimum values about 1 week after hatching. In contrast, plasma luteinizing hormone (LH) concentrations were low during the incubation period, but after hatching they gradually increased and reached peak values immediately after removal of chicks. Concentrations of oestradiol in plasma were low in the incubation and brooding stages but increased significantly immediately after removal of chicks. In the second breeding cycle, changes in PRL and LH concentrations were similar to those observed in the first breeding cycle except that even greater increases in plasma LH and oestradiol concentrations were observed one week after hatching when the chicks were removed. These results suggest that coexistence of newly hatched chicks may suppress LH secretion from the pituitary of the hen in the natural breeding cycle.

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“…An explanation may be that glycosylated chicken and ovine prolactin are removed early in the purification method and that this is not the case for the turkey prolactin prep¬ aration. Turkey prolactin was purified by isotachophoresis (Proudman & Corcoran, 1981) which is unlikely to distinguish between glycosylated and non-glycosylated prolactin. Both chicken and ovine prolactin have been isolated by the more traditional techniques of extraction, salt precipitation and ionexchange chromatography in which glycoproteins (including luteinizing hormone, follicle-stimulating hormone and thyroid-stimulating hormone together with any glycosylated GH or prolactin) are removed initially in the fractionation procedure.…”

Section: Discussionmentioning

confidence: 99%

Phosphorylation of prolactin and growth hormone

Arámburo¹,

Montiel²,

Proudman³

et al. 1992

Journal of Molecular Endocrinology

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To determine whether GH and prolactin could be phosphorylated, turkey GH, chicken GH, chicken prolactin and turkey prolactin were incubated in vitro with the catalytic subunit of protein kinase A and [gamma-32P]ATP. Phosphorylation was assessed after sodium dodecyl sulphate-polyacrylamide gel electrophoresis, Western blotting and autoradiography. Polyacrylamide electrophoresis showed that both purified native chicken GH and turkey GH were phosphorylated under the conditions employed. However, the glycosylated variant of chicken GH did not appear to be labelled. Chicken prolactin, turkey prolactin and the glycosylated variant of turkey prolactin were all intensely phosphorylated by protein kinase A. Ovine and rat prolactins could also be phosphorylated by protein kinase A. The phosphate content of different native prolactin (turkey, ovine and rat) and GH (ovine and chicken) preparations was also determined and found to be significant. Chicken pituitary cells in primary culture incorporated 32P in GH- and prolactin-like bands isolated by non-denaturing polyacrylamide gel electrophoresis, and this was stimulated by phorbol myristate acetate. Phosphorylation of GH and prolactin may thus explain some of the charge heterogeneity of these hormones.

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Turkey Prolactin: Purification by Isotachophoresis and Partial Characterization

Abstract: Preparative isotachophoresis (ITP) has been employed in the purification of prolactin from the pituitary gland of the domestic turkey. Prolactin was purified in relatively few steps and required

Cited by 25 publications

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Reductions in plasma LH concentration and testicular weight in ring doves following intracranial injection of prolactin or growth hormone

Reductions in plasma LH concentration and testicular weight in ring doves following intracranial injection of prolactin or growth hormone

Effects of removal of chicks from hens on concentrations of prolactin, luteinizing hormone and oestradiol in plasma of brooding Gifujidori hens

Phosphorylation of prolactin and growth hormone

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