Lactogenic and Pigeon Crop-Stimulating Activities of Human Pituitary Growth Hormone Preparations

Forsyth, Isabel A.; Folley, S. J.; Chadwick, A.

doi:10.1677/joe.0.0310115

Cited by 90 publications

(32 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Males from the same line are usually fertile but exhibit dramatic reductions in plasma prolactin levels [ 10] and in the number and secretory activity of lactotrophs [ 12], as well as significant increases in noradrenergic activity in the median emi nence [11], and in plasma LH levels [10,11], along with the appearance o f 'castration cells' in the adenohypophysis [12], From the nature of these abnormalities and from observa tions of relatively normal reproductive performance in mice ex pressing bovine or ovine GH genes [4; Yun, Wagner, Bartke and Naar, unpubl. observations], we suspected that the effects of m M T/hGH transgene expression are due largely, if not ex clusively, to the well-documented prolactin activity of hGH in rodents [13,14], In order to test this hypothesis, we have com pared various parameters of neuroendocrine function in mMT/ hGH transgenic mice and in mice expressing hGH variant …”

mentioning

confidence: 99%

Effects of Heterologous Growth Hormones on Hypothalamic and Pituitary Function in Transgenic Mice

et al. 1991

View full text Add to dashboard Cite

The expression of the mouse metallothionein-I (mMT) promoter/human growth hormone (hGH) fusion gene in transgenic mice leads to female sterility and major alterations in the function of the hypothalamic-adenohypophyseal system. These alterations include increases in median-eminence norepinephrine turnover and plasma LH levels, and a decrease in plasma prolactin levels in intact males, and an increase in median-eminence dopamine turnover combined with the suppression of plasma prolactin levels in ovariectomized females. To further characterize these changes and to determine whether they are due to the lactogenic or somatotropic activity of hGH, we have studied hypothalamic and pituitary function in transgenic mice expressing mMT/hGH, mMT/hGH- B ‘variant’, or mMT/bGH fusion genes. In males, the expression of the hGH· B gene was associated with a reduction in pituitary prolactin release in vitro and an increase in LH response to LHRH stimulation, while the bGH transgene did not affect any of the examined parameters of LH and prolactin release. Median-eminence norepinephrine turnover was increased in each of the three lines of transgenic males, while median-eminence dopamine turnover was reduced only in animals expressing the hGH · B gene. In ovariectomized females, plasma LH was suppressed by hGH variant expression, while median-eminence norepinephrine turnover was suppressed in both hGH · B and bGH animals. The turnover of dopamine was increased in the median eminence of females expressing either of the human genes (hGH or gHG- · B) and reduced in the median eminence of ovariectomized bGH females. We conclude that the hGH· B gene is weakly lactogenic in mice, and that the chronic stimulation of either GH receptors (by bGH) or both GH and prolactin receptors (by hGH or hGH · B) can lead to profound alterations in the metabolism of hypothalamic neurotransmitters and pituitary hormone release.

show abstract

mentioning

confidence: 99%

Effects of Heterologous Growth Hormones on Hypothalamic and Pituitary Function in Transgenic Mice

et al. 1991

View full text Add to dashboard Cite

show abstract

“…The crop-sac response was evaluated on a 4 plus scale according to the semiquantitative method described in Forsyth el al. [9], slightly modified control animals did not show any crop-sac stimulation thus the score given was equal to 0. Scanning electron microscopy (SEM) was performed on crop-sac fixed in 5% glutaraldehyde in phosphate buffer 0.1 M, pH 7.2 at 4 C and then dehydrated in Freon 12 and Freon 13 by means of BOMAR 50.…”

Section: Methodsmentioning

confidence: 96%

“…The biological cropsac response in pigeons [9] has been used for assaying plasma PRL in mammalian species…”

mentioning

confidence: 99%

Crop-Sac Response after Systemic and Intraventricular Administration of Neuroleptic Drugs

Nisticò¹,

Germanà²,

Ciriaco³

et al. 1979

Neuroendocrinology

View full text Add to dashboard Cite

Present experiments were aimed at studying in pigeons the effects of some neuroleptic agents given systemically or into the 3rd cerebral ventricle on PRL secretion and following morphological changes of the crop-sac mucosa both by classical histological methods and scanning electron microscopy. In addition, such changes were also evaluated on the basis of a semiquantitative method using a 1-4 rating scale. 3- or 5-day systemic treatment with reserpine, haloperidol and (±)-sulpiride produced an intense crop-sac response consisting of a marked epithelial hyperplasia and presence of milk-like material. Similarly, a much lower dose of haloperidol, clozapine, and the two enantiomers of sulpiride given into the 3rd cerebral ventricle for 3 consecutive days produced a marked crop-sac response. The /-sulpiride was more active in comparison to the d-enantiomer. In conclusion, present experiments show that, similarly to mammals, in pigeons neuroleptic drugs are able to stimulate prolactin secretion and suggest that these effects are mediated through an action at the hypothalamic and/or pituitary level by removing a tonic dopaminergic inhibition.

show abstract

“…HCS and HGH are similarly less active in the pigeon crop assay than when tested in rabbits (Forsyth, 1968). In man the specific importance of HCS in breast development during pregnancy and the stimulation of lactation is unknown.…”

Section: A C T I O N Smentioning

confidence: 95%

Human Chorionic Somatomamotraophin and Its Clinical Significance

Hartog

1972

Clinical Endocrinology

View full text Add to dashboard Cite

Lactogenic and Pigeon Crop-Stimulating Activities of Human Pituitary Growth Hormone Preparations

Cited by 90 publications

References 16 publications

Effects of Heterologous Growth Hormones on Hypothalamic and Pituitary Function in Transgenic Mice

Effects of Heterologous Growth Hormones on Hypothalamic and Pituitary Function in Transgenic Mice

Crop-Sac Response after Systemic and Intraventricular Administration of Neuroleptic Drugs

Human Chorionic Somatomamotraophin and Its Clinical Significance

Contact Info

Product

Resources

About