scholarly journals Immunohistochemical Proliferation Markers May Overestimate the Growth Potential After Ionizing Radiation: In Vivo Study in the Rat Anterior Pituitary Gland

2003 ◽  
Vol 43 (11) ◽  
pp. 521-527 ◽  
Author(s):  
Satoshi NAKASU ◽  
Yoko NAKASU ◽  
Tadateru FUKAMI ◽  
Masayuki MATSUDA
Keyword(s):  
Ionizing Radiation ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Growth Potential ◽  
In Vivo Study ◽  
Proliferation Markers

scholarly journals In vivo xenoestrogenic actions of cadmium and arsenic in anterior pituitary and uterus

Reproduction ◽  
2016 ◽  
Vol 152 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sonia A Ronchetti ◽  
Gisela V Novack ◽  
María S Bianchi ◽  
Melisa C Crocco ◽  
Beatriz H Duvilanski ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Anterior Pituitary Gland ◽  
Ovariectomized Rats ◽  
Serum Prolactin ◽  
Pituitary Hormone ◽  
Low Doses ◽  
Proliferation Markers

Cadmium (Cd) and arsenic (iAs) are toxic metals ubiquitously present in the environment. Both pollutants exert nonmonotonic dose responses, being mostly cytotoxic at high concentrations but mimicking estrogen (E2) effects at low doses. Xenoestrogenic activity of Cd and iAs has been demonstrated in different hormone-dependent tumor cell lines; however, their actionsin vivoremain largely unknown. Here, we investigated whetherin vivoadministration of low doses of Cd and iAs through drinking water would display xenoestrogenic effects in the anterior pituitary gland and uterus of ovariectomized rats. Cd (1ppm) and iAs (0.1ppm) exposure increased the wet weight of anterior pituitary gland and uterus and induced proestrus- and estrus-like vaginal smears. Both metals stimulate cell proliferation of these tissues as they increased the expression of proliferation markers. More importantly, they augmented soluble guanylyl cyclase α1 subunit expression, which has been linked to hormone-dependent tumor progression. Also, Cd and iAs modified protein levels of full-length estrogen receptor α and its truncated variants in an E2-like manner. Anterior pituitary hormone secretion was differentially affected by both metals. Luteinizing hormone synthesis and release were strongly diminished after Cd exposure and only mildly reduced by iAs. Both metals were able to increase prolactin synthesis, although only iAs augmented serum prolactin levels. This study shows for the first time that Cd and iAs exert strong xenoestrogenic effects on anterior pituitary gland at low doses. The differences between Cd and iAs E2-like behavior indicate that other Cd- and iAs-specific mechanisms could be involved. Altogether, these results contribute to the knowledge of reproductive disorders associated with Cd and iAs environmental contamination.

scholarly journals Intercellular communication in the rat anterior pituitary gland: an in vivo and in vitro study

1975 ◽  
Vol 67 (2) ◽  
pp. 469-476 ◽  
Author(s):  
WH Fletcher ◽  
NC Anderson ◽  
JW Everett
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
In Vitro Study ◽  
Anterior Pituitary Gland ◽  
Stimulus Secretion Coupling ◽  
Unpublished Observation ◽  
Cellular Ca

The concept of "stimulus-secretion coupling" suggested by Douglas and co-workers to explain the events related to monamine discharge by the adrenal medulla (5, 7) may be applied to other endocrine tissues, such as adrenal cortex (36), pancreatic islets (4), and magnocellular hypothalamic neurons (6), which exhibit a similar ion-dependent process of hormone elaboration. In addition, they share another feature, that of joining neighbor cells via membrane junctions (12, 26, and Fletcher, unpublished observation). Given this, and the reports that hormone secretion by the pars distalis also involves a secretagogue-induced decrease in membrane bioelectric potential accompanied by a rise in cellular [Ca++] (27, 34, 41), it was appropriate to test the possibility that cells of the anterior pituitary gland are united by junctions.

Bovine Posterior Pituitary Extract Stimulates Prolactin Release from the Anterior Pituitary Gland In Vitro and In Vivo in Cattle

2005 ◽  
Vol 40 (2) ◽  
pp. 184-189 ◽  
Author(s):  
T Hashizume ◽  
T Sasaki ◽  
S Nonaka ◽  
T Hayashi ◽  
M Takisawa ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Posterior Pituitary ◽  
Pituitary Extract ◽  
Prolactin Release

scholarly journals In Vivo and In Vitro Arsenic Exposition Induces Oxidative Stress in Anterior Pituitary Gland

2016 ◽  
Vol 35 (4) ◽  
pp. 463-475 ◽  
Author(s):  
Sonia A. Ronchetti ◽  
María S. Bianchi ◽  
Beatriz H. Duvilanski ◽  
Jimena P. Cabilla
Keyword(s):  
Oxidative Stress ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Inorganic Arsenic ◽  
Anterior Pituitary Gland ◽  
Pituitary Cells ◽  
Prolactin Release ◽  
Stress Responsive Genes

Inorganic arsenic (iAs) is at the top of toxic metalloids. Inorganic arsenic-contaminated water consumption is one of the greatest environmental health threats worldwide. Human iAs exposure has been associated with cancers of several organs, neurological disorders, and reproductive problems. Nevertheless, there are no reports describing how iAs affects the anterior pituitary gland. The aim of this study was to investigate the mechanisms involved in iAs-mediated anterior pituitary toxicity both in vivo and in vitro. We showed that iAs administration (from 5 to 100 ppm) to male rats through drinking water increased messenger RNA expression of several oxidative stress-responsive genes in the anterior pituitary gland. Serum prolactin levels diminished, whereas luteinizing hormone (LH) levels were only affected at the higher dose tested. In anterior pituitary cells in culture, 25 µmol/L iAs significantly decreased prolactin release in a time-dependent fashion, whereas LH levels remained unaltered. Cell viability was significantly reduced mainly by apoptosis evidenced by morphological and phosphatidylserine externalization studies. This process is characterized by early depolarization of mitochondrial membrane potential and increased levels of reactive oxygen species. Expression of some key oxidative stress-responsive genes, such as heme oxygenase-1 and metallothionein-1, was also stimulated by iAs exposure. The antioxidant N-acetyl cysteine prevented iAs-induced effects on the expression of oxidative stress markers, prolactin release, and apoptosis. In summary, the present work demonstrates for the first time that iAs reduces prolactin release both in vivo and in vitro and induces apoptosis in anterior pituitary cells, possibly resulting from imbalanced cellular redox status.

In vivo correlation between c-Fos expression and corticotroph stimulation by adrenocorticotrophic hormone secretagogues in rat anterior pituitary gland

2007 ◽  
Vol 331 (3) ◽  
pp. 589-594 ◽  
Author(s):  
Shu Takigami ◽  
Ken Fujiwara ◽  
Motoshi Kikuchi ◽  
Takashi Yashiro
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Adrenocorticotrophic Hormone ◽  
Fos Expression

scholarly journals Gonadotrope Plasticity at Cellular and Population Levels

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4729-4739 ◽  
Author(s):  
Zahara Alim ◽  
Cheryl Hartshorn ◽  
Oliver Mai ◽  
Iain Stitt ◽  
Colin Clay ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Ex Vivo ◽  
Single Cells ◽  
Anterior Pituitary Gland ◽  
Female Mice ◽  
Model Animal ◽  
Pituitary Glands ◽  
Acute Changes

Abstract Hormone-secreting cells within the anterior pituitary gland may form organized and interdigitated networks that adapt to changing endocrine conditions in different physiological contexts. For gonadotropes, this might reflect a strategy to cope with acute changes throughout different female reproductive stages. The current study examined gonadotropes in female mice at characteristically different hormonal stages: prepubertal, postpubertal, and lactating. Gonadotrope plasticity was examined at the level of the whole population and single cells at different stages by imaging both fixed and live pituitary slices. The use of a model animal providing for the identification of selectively fluorescent gonadotropes allowed the particular advantage of defining cellular plasticity specifically for gonadotropes. In vivo analyses of gonadotropes relative to vasculature showed significantly different gonadotrope distributions across physiological states. Video microscopy studies using live slices ex vivo demonstrated pituitary cell plasticity in the form of movements and protrusions in response to GnRH. As positive feedback from rising estradiol levels is important for priming the anterior pituitary gland for the LH surge, experiments provide evidence of estradiol effects on GnRH signaling in gonadotropes. The experiments presented herein provide new insight into potential plasticity of gonadotropes within the anterior pituitary glands of female mice.

Gonadotropin-releasing hormone-Cu complex (Cu-GnRH) transcriptional activity in vivo in the female rat anterior pituitary gland

2020 ◽  
Vol 156 ◽  
pp. 67-75
Author(s):  
Grzegorz Kotarba ◽  
Marlena Zielinska-Gorska ◽  
Katarzyna Biernacka ◽  
Alina Gajewska
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Transcriptional Activity ◽  
Gonadotropin Releasing Hormone ◽  
Anterior Pituitary Gland ◽  
Female Rat ◽  
Releasing Hormone ◽  
Cu Complex

Effects of Angiotensin II on LHRH Release, as Measured by in vivo Microdialysis of the Anterior Pituitary Gland of Conscious Female Rats

1992 ◽  
Vol 55 (3) ◽  
pp. 276-281 ◽  
Author(s):  
Marianne K. Steele ◽  
Kate N. Stephenson ◽  
John M. Meredith ◽  
Jon E. Levine
Keyword(s):  
Angiotensin Ii ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
In Vivo Microdialysis ◽  
Anterior Pituitary Gland ◽  
Female Rats ◽  
Lhrh Release
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