Anin vivo bioassay for TSH-releasing factor (TRF)

Yamazaki, Eiichi; Sakiz, E; Guillemin, Roger

doi:10.1007/bf02150659

Cited by 27 publications

(5 citation statements)

References 3 publications

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“…This type of in vitro assay for TRF would have the same limitations that we have described earlier for the in vitro CRF assay (17). For a routine assay of TRF activity we prefer to use the simpler in vivo method described recently by this laboratory (18).…”

Section: Discussionmentioning

confidence: 97%

In VitroSecretion of Thyrotropin (TSH): Stimulation by a Hypothalamic Peptide (TRF)

et al. 1963

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Section: Discussionmentioning

confidence: 97%

In VitroSecretion of Thyrotropin (TSH): Stimulation by a Hypothalamic Peptide (TRF)

et al. 1963

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“…Bioassays for TRF. Three bioassay methods were used throughout this series of experiments: (a) a minor modification of the method originally described by Yamazaki et al [24] (sensitivity < 1.5 U TRF); (b) the assay method using the mouse as described by R edding <?/ al. [15] (sensitivity < 0.75 U TRF); (c) an assay method using mice (male 20 g), given 4 /zei1251 i.p.…”

Section: Trf O F Natural Originmentioning

confidence: 99%

In vitro Plasma Inactivation of Thyrotropin Releasing Factor (TRF) and Related Peptides. Its Inhibition by Various Means and by the Synthetic Dipeptide PCA-His-OME

Vale¹,

Burgus²,

Dunn³

et al. 1971

Horm Res Paediatr

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Incubation in vitro of natural (ovine) or synthetic TRF (PCA-His-Pro-NH₂) with rat blood, plasma, or reconstituted lyophilized serum destroys the biological activity. Inactivation of TRF by normal plasma takes place at 0 °C but at a slower rate than at 37 °C. Plasma obtained from rats several weeks after hypophysectomy and/ or hypophysectomy + thyroidectomy inactivates TRF. TRF activity is not recovered from TRF incubated in plasma when the incubate is treated with NaCl (4 m), ethanol (80% v/v) or HCl (to pH 1). Plasma inactivation of TRF is completely prevented by pretreatment of the plasma with ethanol (80% v/v); heating of plasma at 65 °C for 15 min also destroys the ability of plasma to inactivate TRF. The data reported are consistent with the hypothesis that plasma contains an enzyme (s) which destroys the activity of TRF. Plasma was also found to destroy the biological activity of PCA-His-Pro-OMe and PCA-His-Pro-OH (2 synthetic tripeptides with TRF activity). The biological activity of PCA-His-Pro-OH is destroyed in vitro at a slower rate by plasma than that of PCA-His-Pro-NH₂ or natural TRF. Addition of the dipeptide analogue of TRF, PCA-His-OMe, prevents in vitro the inactivation of TRF by plasma.

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“…Yamazaki, Sakiz and Guillemin (22) found also that an ovine hypothalamic peptide preparation had TRF activity in the rat. Recently, Reichlin (11) published a preliminary report that an ox pituitary stalk-median eminence extract, purified by gel filtration, had TRF activity when given to mice.…”

mentioning

confidence: 91%

Effect of Thyrotropin Releasing Factor (TRF) of Ovine, Bovine, Porcine and Human Origin on Thyrotropin Releasein Vitroandin Vivo

Bowers

Redding

1965

Endocrinology

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Peptide-like materials which release thyrotropin (TSH) from the pituitary in vivo and in vitro were obtained from the hypothalamus of the ox, sheep and pig and from human neurohypophysial tissue. Thyrotropic hormone releasing factor (TRF) activity was measured in vitro by the isolated rat pituitary incubation method of Saffran and Schally. TSH secreted into the medium was assayed by the release of 13I I from the thyroid gland of the mouse as described by McKenzie and by the uptake of 131 I by the tadpole's thyroid as described by Bowers. Addition of TRF preparations to the incubation media significantly increased the release of TSH from the pituitaries. TSH release in vitro was related to the dose of TRF preparations from all 4 species. One TRF preparation was active in vitro at a dose of 10 ng. TRF activity was also measured in vivo in the rat. TRF preparations from each species increased plasma TSH levels in thyroidectomized, triiodothyronine-treated rats. These studies support the concept that the hypothalamus takes part in the regulation of TSH release from the anterior pituitary gland. (Endocrinology 77: 609, 1965)

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Anin vivo bioassay for TSH-releasing factor (TRF)

Cited by 27 publications

References 3 publications

In VitroSecretion of Thyrotropin (TSH): Stimulation by a Hypothalamic Peptide (TRF)

In VitroSecretion of Thyrotropin (TSH): Stimulation by a Hypothalamic Peptide (TRF)

In vitro Plasma Inactivation of Thyrotropin Releasing Factor (TRF) and Related Peptides. Its Inhibition by Various Means and by the Synthetic Dipeptide PCA-His-OME

Effect of Thyrotropin Releasing Factor (TRF) of Ovine, Bovine, Porcine and Human Origin on Thyrotropin Releasein Vitroandin Vivo

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