scholarly journals Pyrethroid Insecticide Cypermethrin Modulates Gonadotropin Synthesis via Calcium Homeostasis and ERK1/2 Signaling in LβT2 Mouse Pituitary Cells

2017 ◽  
Vol 162 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Feixue Li ◽  
Huihui Ma ◽  
Jing Liu
Keyword(s):  
Calcium Homeostasis ◽  
Pyrethroid Insecticide ◽  
Pituitary Cells ◽  
Mouse Pituitary

scholarly journals IGF-I regulates pro-opiomelanocortin and GH gene expression in the mouse pituitary gland

2003 ◽  
Vol 178 (1) ◽  
pp. 71-82 ◽  
Author(s):  
J Honda ◽  
Y Manabe ◽  
R Matsumura ◽  
S Takeuchi ◽  
S Takahashi
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Northern Blotting ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Gh Treatment ◽  
Gh Receptor ◽  
Pomc Mrna ◽  
Igf I ◽  
Mouse Pituitary

IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF-I stimulates the proliferation of corticotrophs in the mouse pituitary. These results suggested that somatotrophs regulate corticotrophic functions as well as somatotrophic functions by the mediation of IGF-I molecules. The present study aimed to clarify factors regulating pituitary IGF-I expression and also the roles exerted by IGF-I within the mouse anterior pituitary gland. Mouse anterior pituitary cells were isolated and cultured under serum-free conditions. GH (0.5 or 1 microg/ml), ACTH (10(-8) or 10(-7) M), GH-releasing hormone (GHRH; 10(-8) or 10(-7) M), dexamethasone (DEX; 10(-8) or 10(-7) M) and estradiol-17beta (e2; 10(-11) or 10(-9) M) were given for 24 h. IGF-I mRNA levels were measured using competitive RT-PCR, and GH and pro-opiomelanocortin (POMC) mRNA levels were measured using Northern blotting analysis. GH treatment significantly increased IGF-I mRNA levels (1.5- or 2.1-fold). ACTH treatment did not alter GH and IGF-I mRNA levels. IGF-I treatment decreased GH mRNA levels (0.7- or 0.5-fold), but increased POMC mRNA levels (1.8-fold). GH treatment (4 or 8 microg/ml) for 4 days increased POMC mRNA levels. GHRH treatment increased GH mRNA levels (1.3-fold), but not IGF-I mRNA levels. DEX treatment significantly decreased IGF-I mRNA levels (0.8-fold). e2 treatment did not affect IGF-I mRNA levels. GH receptor mRNA, probably with GH-binding protein mRNA, was detected in somatotrophs, and some mammotrophs and gonadotrophs by in situ hybridization using GH receptor cDNA as a probe. These results suggested that IGF-I expression in somatotrophs is regulated by pituitary GH, and that IGF-I suppresses GH expression and stimulates POMC expression at the transcription level. Pituitary IGF-I produced in somatotrophs is probably involved in the regulation of somatotroph and corticotroph functions.

scholarly journals Reporter Expression, Induced by a Growth Hormone Promoter-Driven Cre Recombinase (rGHp-Cre) Transgene, Questions the Developmental Relationship between Somatotropes and Lactotropes in the Adult Mouse Pituitary Gland

Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 1946-1953 ◽  
Author(s):  
Raul M. Luque ◽  
Geraldine Amargo ◽  
Shinya Ishii ◽  
Corrinne Lobe ◽  
Roberta Franks ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Transgenic Mouse ◽  
Anterior Pituitary ◽  
Adult Mouse ◽  
Small Subset ◽  
Parental Line ◽  
Pituitary Cells ◽  
Placental Alkaline Phosphatase ◽  
Developmental Studies ◽  
Mouse Pituitary

This report describes the development and validation of the rGHp-Cre transgenic mouse that allows for selective Cre-mediated recombination of loxP-modified alleles in the GH-producing cells of the anterior pituitary. Initial screening of the rGHp-Cre parental line showed Cre mRNA was specifically expressed in the anterior pituitary gland of adult Cre+/− mice and cephalic extracts of e17 Cre+/− fetuses. Heterozygote rGHp-Cre transgenic mice were crossbred with Z/AP reporter mice to generate Cre+/−,Z/AP+/− offspring. In this model system, the GH promoter-driven, Cre-mediated recombination of the Z/AP reporter leads to human placental alkaline phosphatase (hPLAP) expression that serves to mark cells that currently produce GH, in addition to cells that would have differentiated from GH cells but currently do not express the GH gene. Double immunocytochemistry of adult male and female Cre+/−,Z/AP+/− pituitary cells revealed the majority (∼99%) of GH-producing cells of the anterior pituitary also expressed hPLAP, whereas ACTH-, TSH-, and LH-producing cells were negative for hPLAP, confirming previous reports that corticotropes, thyrotropes, and gonadotropes develop independently of the somatotrope lineage. A small subset (∼10%) of the prolactin-producing cells was positive for hPLAP, consistent with previous reports showing lactotropes can arise from somatotropes during pituitary development. However, the fact that 90% of prolactin-producing cells were negative for hPLAP suggests that the majority of lactotropes in the adult mouse pituitary gland develop independently of the somatotrope lineage. In addition to developmental studies, the rGHp-Cre transgenic mouse will provide a versatile tool to study the role of a variety of genes in somatotrope function and neoplastic transformation.

EFFECT OF EXOGENOUS THYROXINE ON 3H-THYMIDINE UPTAKE IN MOUSE PITUITARY GLAND

1969 ◽  
Vol 61 (1) ◽  
pp. 133-136 ◽  
Author(s):  
B. Messier
Keyword(s):  
Thyroid Gland ◽  
Oral Administration ◽  
Pituitary Gland ◽  
Intact Animal ◽  
Thymidine Uptake ◽  
Pituitary Cells ◽  
Thyroxine Treatment ◽  
Before And After ◽  
Mouse Pituitary

ABSTRACT Destruction of the thyroid gland in the mouse induces proliferation of pituitary thyrotropes. This phenomenon was studied quantitatively with 3H-thymidine, before and after oral administration of thyroxine. The frequency of radioactive cells in the intact animal is 3.4 per 10 000 pituitary cells. This value rises to 19.6, 18.4 and 56.0 four, eight, and twelve months after thyroidectomy, respectively. All these increased values are brought back to normal levels after 5 to 10 days of thyroxine treatment. Thus, the intense proliferation of pituitary thyrotropes following thyroidectomy is still responsive to the homeostatic action of thyroxine.

Immunocytochemical evidence that S-100-positive cells of the mouse anterior pituitary contain interleukin-6 immunoreactivity.

1993 ◽  
Vol 41 (2) ◽  
pp. 151-156 ◽  
Author(s):  
H Vankelecom ◽  
P Matthys ◽  
J Van Damme ◽  
H Heremans ◽  
A Billiau ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Anterior Pituitary ◽  
Tumor Cell Line ◽  
Polyclonal Antiserum ◽  
Positive Staining ◽  
Pituitary Cells ◽  
S 100 ◽  
Mouse Pituitary ◽  
Acth Secreting

We have previously shown that bioactive interleukin-6 (IL-6) is produced by rat and mouse (anterior) pituitary cells in vitro. Since the amount produced correlated with the presence of S-100-containing folliculostellate (FS) cells, these cells were suggested to be a source of IL-6 in the anterior pituitary (AP) lobe. In the present study we used immunocytochemical techniques to confirm this presumption. Freshly isolated mouse pituitary cells were subjected to immunocytochemical procedures whereby two different (neutralizing) monoclonal antibodies (MAb) against mouse IL-6 (6B4 and 20F3) and a polyclonal antiserum raised against bovine S-100 were used as primary antibodies. Single immunostaining revealed a small portion of mouse pituitary cells (about 6.5%) to be positive for IL-6 immunoreactivity with both antibodies. Importantly, the same proportion of cells was found to be IL-6 positive if only the AP was used as the cell source. About 7.5% of the pituitary cells stained for the presence of S-100 immunoreactivity. Positive staining for IL-6 was also found in pituitary cell samples from 2-day-old monolayer cultures and from redispersed 9-day-old histotypic aggregates, which both secreted bioassayable IL-6. In contrast, no IL-6 staining was found in AtT-20 cells, an established ACTH-secreting tumor cell line of the mouse pituitary which did not secrete bioactive IL-6. The specificity of the IL-6 immunostaining was demonstrated by a total loss of staining when MAb 6B4 was omitted or replaced by irrelevant rat IgG. Conclusively, pre-adsorption of the anti-IL-6 MAb (6B4) with recombinant mouse IL-6 totally abolished staining of pituitary cells. Double immunostaining for IL-6 and S-100 revealed that most if not all of the IL-6-containing pituitary cells were positive for S-100. Few of the S-100-containing cells did not stain for IL-6. These results confirm our previous hypothesis that FS cells, characterized by immunostaining of S-100 protein, contain bioactive and immunoreactive IL-6 and therefore are very likely producers of IL-6 in the AP. Furthermore, our results suggest that IL-6 is implicated in the local regulatory role ascribed to FS cells in the pituitary gland.

scholarly journals Transforming growth factor-alpha stimulates proliferation of mammotrophs and corticotrophs in the mouse pituitary

2000 ◽  
Vol 165 (2) ◽  
pp. 493-501 ◽  
Author(s):  
S Oomizu ◽  
J Honda ◽  
S Takeuchi ◽  
T Kakeya ◽  
T Masui ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Egf Receptor ◽  
Transforming Growth Factor ◽  
Receptor Expression ◽  
Pcr Analysis ◽  
Transforming Growth Factor Alpha ◽  
Pituitary Cells ◽  
Factor Alpha ◽  
Mouse Pituitary

Oestrogen stimulates the proliferation of pituitary cells. The present study was designed to clarify the involvement of transforming growth factor-alpha (TGF-alpha) in the oestrogen-induced growth of mouse pituitary cells in vitro. Anterior pituitary cells obtained from ICR male mice were cultured in a primary serum-free culture system. Proliferation of pituitary cells was detected by monitoring the cellular uptake of bromodeoxyuridine. Secretory cell types were immunocytochemically determined. Treatment with TGF-alpha (0.1 and 1 ng/ml) for 5 days stimulated cell proliferation. Since TGF-alpha binds to the epidermal growth factor (EGF) receptor, this action may be exerted through the EGF receptor. Oestradiol-17beta (OE(2), 10(-)(9) M) stimulated mammotrophic and corticotrophic cell proliferation. RG-13022, an EGF receptor inhibitor, inhibited the cell proliferation induced by EGF or OE(2), showing that the EGF receptor was involved in the growth response in mammotrophs and corticotrophs. Treatment with antisense TGF-alpha oligodeoxynucleotide (ODN) inhibited the cell proliferation induced by OE(2), but treatment with antisense EGF ODN did not. RT-PCR analysis revealed that OE(2) stimulated TGF-alpha mRNA and EGF receptor mRNA expression. These results indicate that TGF-alpha mediates the stimulatory effect of oestrogen on the pituitary cell proliferation in a paracrine or autocrine manner, and that EGF receptor expression is stimulated by oestrogen.

scholarly journals Lectin-labeled membrane is transferred to the Golgi complex in mouse pituitary cells in vivo.

1987 ◽  
Vol 35 (4) ◽  
pp. 489-498 ◽  
Author(s):  
B J Balin ◽  
R D Broadwell
Keyword(s):  
Golgi Complex ◽  
Secretory Granules ◽  
Surface Membrane ◽  
Dense Core ◽  
Secretory Cells ◽  
Pituitary Cells ◽  
Posterior Pituitary ◽  
Peroxidase Reaction ◽  
Mouse Pituitary

Labeling of the Golgi complex with the lectin conjugate wheat germ agglutinin-horseradish peroxidase (WGA-HRP), which binds to cell surface membrane and enters cells by adsorptive endocytosis, was analyzed in secretory cells of the anterior, intermediate, and posterior lobes of mouse pituitary gland in vivo. WGA-HRP was administered intravenously or by ventriculo-cisternal perfusion to control and salt-stressed mice; post-injection survival times were 30 min-24 hr. Peroxidase reaction product was identified within the extracellular clefts of anterior and posterior pituitary lobes through 24 hr but was absent in intermediate lobe. Endocytic vesicles, spherical endosomes, tubules, dense and multivesicular bodies, the trans-most saccule of the Golgi complex, and dense-core secretory granules attached or unattached to the trans Golgi saccule were peroxidase-positive in the different types of anterior pituitary cells and in perikarya of supraoptico-neurohypophyseal neurons; endoplasmic reticulum and the cis and intermediate Golgi saccules in the same cell types were consistently devoid of peroxidase reaction product. Dense-core secretory granules derived from cis and intermediate Golgi saccules in salt-stressed supraoptic perikarya likewise failed to exhibit peroxidase reaction product. The results suggest that in secretory cells of anterior and posterior pituitary lobes, WGA-HRP, initially internalized with cell surface membrane, is eventually conveyed to the trans-most Golgi saccule, in which the lectin conjugate and associated membrane are packaged in dense-core secretory granules for export and potential exocytosis of the tracer. Endoplasmic reticulum and the cis and intermediate Golgi saccules appear not to be involved in the endocytic/exocytic pathways of pituitary cells exposed to WGA-HRP.

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