Extra-pituitary growth hormone in peripheral tissues of early chick embryos

Harvey, S.; Johnson, C. D. M.; Sanders, Esmond J.

doi:10.1677/joe.0.1660489

Cited by 59 publications

(58 citation statements)

References 49 publications

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“…These findings extend preliminary observations by Harvey et al (2000) using paraformaldehyde-fixed tissues from ED 6 and ED 7 embryos. The cellular localization of GH staining in the neural tube, dorsal and ventral root ganglia, notochord, heart and limb bud was, however, much clearer in this (A and B).…”

Section: Discussionsupporting

confidence: 90%

Extrapituitary GH in the chicken: underestimation of immunohistochemical staining by Carnoy's fixation

Murphy¹,

Peek²,

Baudet³

et al. 2003

Journal of Endocrinology

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GH has previously been shown to be present in peripheral extrapituitary tissues of chick embryos, but the cellular distribution of GH immunoreactivity is still uncertain because of differing immunohistochemical findings. The possibility that this uncertainty reflects differences in fixation of the embryonic tissues was assessed by comparing GH immunoreactivity in tissues fixed in 4% (w/v) paraformaldehyde or Carnoy's fluid (60% ethanol (v/v); 30% chloroform (v/v); 10% acetic acid (v/v)).A widespread distribution of GH immunoreactivity was seen in paraformaldehyde-fixed tissues, although it was particularly intense in the spinal cord, dorsal and ventral root ganglia, notochord, myotome, epidermis, crop, heart, lung and humerus. In marked contrast, GH immunoreactivity in embryonic tissues fixed with Carnoy's was more discrete and mainly restricted to marginal and mantle layers of the spinal cord, spinal nerves, the ventral root ganglia and the extensor nerve of the anterior limb bud. Since these are neural derivatives, Carnoy's fixation appears to preferentially result in neural GH staining, whereas GH staining in neural and non-neural tissues is seen after paraformaldehyde fixation. Carnoy's, because it is a precipitive fixative, may only fix large GH moieties, whereas GH in peripheral tissues includes numerous molecular variants, many of which are of relatively small size. Paraformaldehyde, because it is a cross-linking fixative, preferentially fixes peptides and small proteins, and it may therefore fix more GH moieties than Carnoy's fluid. Carnoy's fixation appears to underestimate GH immunoreactivity in immunohistochemical studies on the cellular distribution of GH-like proteins in embryonic chicks.

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Section: Discussionsupporting

confidence: 90%

Extrapituitary GH in the chicken: underestimation of immunohistochemical staining by Carnoy's fixation

Murphy¹,

Peek²,

Baudet³

et al. 2003

Journal of Endocrinology

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“…However, studies that detected extra-pituitary GH in kidney, heart, neural tube, and lungs between E3 and E7 did not detect GH in the pituitary at these same stages (Harvey et al, 2000;Murphy and Harvey, 2001). Even using the highly sensitive technique of RT-PCR, we were not able to detect Gh mRNA expression prior to E8.…”

Section: Temporal Appearance and Spatial Organization Of Somatotropescontrasting

confidence: 65%

“…3g6,7). Most studies report that lactotrope differentiation occurs between E15 and E19 (Kansaku et al, 1994;Woods and Porter, 1998;Allaerts et al, 1999;Harvey et al, 2000;Sasaki et al, 2003). The fact that we detected Prl mRNA at E14 by in situ hybridization likely reflects a delay in the accumulation of significant amounts of PRL protein.…”

Section: Temporal Appearance and Spatial Organization Of Somatotropesmentioning

confidence: 54%

Expression patterns of hormones, signaling molecules, and transcription factors during adenohypophysis development in the chick embryo

Parkinson

Collins

Dufresne

et al. 2010

Developmental Dynamics

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The chick embryo is an ideal model to study pituitary cell-type differentiation. Previous studies describing the temporal appearance of differentiated pituitary cell types in the chick embryo are contradictory. To resolve these controversies, we used RT-PCR to define the temporal onset and in situ hybridization and immunohistochemistry to define the spatial localization of hormone expression within the pituitary. RT-PCR detected low levels of Fshbeta (gonadotropes) and Pomc (corticotropes, melanotropes) mRNA at E4 and Gh (somatotropes), Prl (lactotropes), and Tshbeta (thyrotropes) mRNA at E8. For all hormones, sufficient accumulation of mRNA and/or protein to permit detection by in situ hybridization or immunohistochemistry was observed approximately 3 days later and in all cases corresponded to a notable increase in RT-PCR product. We also describe the expression patterns of signaling (Bmp2, Bmp4, Fgf8, Fgf10, Shh) and transcription factors (Pitx1, Pitx2, cLim3) known to be important for pituitary organogenesis in other model organisms.

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“…Immunocytochemical staining was performed using the avidin-biotinperoxidase (ABC) method, as described in Harvey et al (2000), and 1:500 diluted goat anti-human GH antibody. The specific goat antibody was raised against the amino terminus of human GH (lot A091, Santa Cruz Biotechnology, Santa Cruz, CA) and has been shown by the manufacturer to cross-react with both rat and mouse GH.…”

Section: Immunohistochemistrymentioning

confidence: 99%

“…The abundant and widespread production of GH in peripheral tissues of early embryonic chicks (Harvey et al, 1998) and mice (Pantaleon et al, 1997) nevertheless suggests GH involvement in early development through autocrine or paracrine mechanisms (Harvey and Hull, 1997). The presence of GH, GHR, and a GH-specific response gene (GH response gene-1) in the lungs of early chick embryos (Harvey et al, 2000(Harvey et al, , 2001 supports this possibility, although the presence of GH in extrapituitary organs of the mammalian fetus is poorly documented. GH, however, may act as a local growth or differentiation factor in the mammalian lung, because GH mRNA, detected by reverse transcriptase-polymerase chain reaction (RT-PCR), is present in the alveolar macrophages of adults (Allen et al, 2000) and trace amounts of GH immunoreactivity are present in whole lung extracts of fetal and adult lungs (Kyle et al, 1981;Costa et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

Growth hormone expression in the perinatal and postnatal rat lung

Beyea

Olson

Harvey

2005

Developmental Dynamics

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It is now established that the lung is a target site for pituitary growth hormone (GH) action, because pathophysiological states of pituitary GH excess and deficiency are associated with impaired pulmonary function. The onset of lung development and differentiation is, however, before the ontogenic differentiation of pituitary somatotrophs. GH may be involved, nevertheless, in lung development, because it is present in extrapituitary tissues of preimplantation mouse embryos and in the lung buds of embryonic chickens. The possibility that GH may be expressed in the rat lung during fetal and neonatal development, therefore, has been assessed. GH mRNA was detected in the lung, and its 693-bp sequence was identical to that in the pituitary gland. By in situ hybridization, this transcript was found to be abundantly expressed in the lungs of embryonic day (ED) 17 rats in mesenchymal, mucosal epithelial, and smooth muscle cells. This transcript was expressed in neonates until at least day 14 postnatally and was localized to type I and II epithelial cells and to pulmonary tissue macrophages and alveolar macrophages. GH immunoreactivity paralleled GH mRNA cellular localization throughout the time course studied. This immunoreactivity was specific and was lost after antibody preabsorption. The perinatal and postnatal lung is, therefore, an extrapituitary site of GH gene expression during development. Given that the GH receptor is present in the lung from early development, lung GH may have autocrine and/or paracrine roles in lung growth or differentiation or in pulmonary function.

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Extra-pituitary growth hormone in peripheral tissues of early chick embryos

Cited by 59 publications

References 49 publications

Extrapituitary GH in the chicken: underestimation of immunohistochemical staining by Carnoy's fixation

Extrapituitary GH in the chicken: underestimation of immunohistochemical staining by Carnoy's fixation

Expression patterns of hormones, signaling molecules, and transcription factors during adenohypophysis development in the chick embryo

Growth hormone expression in the perinatal and postnatal rat lung

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