scholarly journals Application of a rapid avidin--biotin--peroxidase complex (ABC) technique to the localization of pituitary hormones at the electron microscopic level.

1982 ◽  
Vol 30 (12) ◽  
pp. 1320-1324 ◽  
Author(s):  
G V Childs ◽  
G Unabia

The new avidin--biotin--peroxidase complex (ABC) technique was applied to ultrathin sections of rat pituitary that were fixed with glutaraldehyde and embedded in Araldite 6005. The primary antisera dilutions that are normally applied for 24-48 hr with the peroxidase-antiperoxidase (PAP) complex technique were used. High background was observed with the ABC method when incubation times were 12-48 hr. Tests were then conducted with shorter incubation times. The staining intensity was measured with a densitometer. Detectable stain was seen after only 15 min in dilutions of 1:10,000 anti-bovine luteinizing hormone (bLH beta), 1:8000 anti-rat thyroid-stimulating hormone (rTSH beta), and 1:20,000 anti-25-39-adrenocorticotropic hormone (25-39ACTH). Optimal LH staining was seen after 30 min, whereas optimal staining for TSH or ACTH required 1 hr. Stain was detectable with a dilution of 1:4000 anti-human follicle-stimulating hormone (hFSH beta) after 30 min and was optimal after 4 hr. Prolonged incubation times with these dilutions decreased the staining intensity because a deposit of high background was produced that appeared as a filigreed network over the cells. When higher dilutions were tested with 2-hr incubation times, optimal staining was seen with 1:30,000 anti-bLH beta, 1:24,000 anti-rTSH beta, 1:30,000 anti-25-39ACTH, and 1:8000 anti-hFSH beta. These tests demonstrate the potential of the ABC method for the rapid detection of small amounts of specific and nonspecific antibodies that are bound to pituitary cells.

1993 ◽  
Vol 41 (7) ◽  
pp. 955-960 ◽  
Author(s):  
B L Lee ◽  
G Unabia ◽  
G Childs

We previously found follistatin (FS) mRNA in gonadotropes [predominantly in cells with luteinizing hormone (LH) antigens] and folliculostellate cells (with S100 antigens) in diestrus rats pituitaries. However, earlier in the cycle, when percentages of gonadotropes are lowest, percentages of cells expressing FS are 1.5-2-fold higher than in diestrus. This study was designed to detect FS mRNA and other pituitary antigens to identify the additional cells with dual in situ hybridization and immunolabeling protocols. The mRNA was detected with biotinylated complementary oligonucleotide probes and avidin-biotin-peroxidase complexes. Significant labeling for FS mRNA was found in cells with the following antigens: growth hormone (GH) (7% of pituitary cells); prolactin (PRL) (5%); S100 protein (5%); follicle-stimulating hormone (FSH beta) (4%); LH beta (3%); and thyroid-stimulating hormone (TSH beta) (3%). Optimal conditions for detection included: overnight plating of > 50,000 cells/well (24-well tray) in media containing 10% fetal bovine serum; hybridization at 37 degrees C; and fixation in 2% glutaraldehyde. Whereas FS is expressed predominantly by LH gonadotropes at midcycle, FS mRNA can be expressed by all types of antigen-bearing cells earlier in the cycle. Its function in the pituitary may relate to its role in binding activin, which would result in inhibition of FSH release. However, since activin inhibits secretion of GH, PRL, and adrenocorticotropin (ACTH), FS may also control activin's effects on these cells. The FS-expressing cells may therefore be paracrine or autocrine regulators.


1981 ◽  
Vol 240 (6) ◽  
pp. E602-E608
Author(s):  
L. Lagace ◽  
F. Labrie ◽  
T. Antakly ◽  
G. Pelletier

To determine possible effects of the time in culture on the responsiveness of the different pituitary cell types to estrogens, rat anterior pituitary cells were incubated up to 20 days in the presence or absence of 10 nM 17 beta-estradiol. Whereas spontaneous luteinizing hormone (LH) and thyroid-stimulating hormone (TSH) release decreased by 85-90%, follicle-stimulating hormone (FSH) and prolactin accumulation in medium were only 50% decreased after 20 days in culture, thus suggesting that the secretion of FSH and prolactin is less dependent on extrinsic stimulatory factors. Estradiol increased spontaneous LH release and its responsiveness to luteinizing hormone-releasing hormone (LH-RH) up to day 16 in culture, whereas the stimulatory effect of the estrogen on FSH secretion was significant only up to day 6. The stimulatory effect of estradiol on basal TSH release was seen up to day 8 in culture, whereas that on spontaneous prolactin release increased progressively after day 8 in culture up to the last time interval studied (20 days). As revealed by immunocytochemistry, the stimulatory effect of estradiol was not due to changes of cell growth.


1975 ◽  
Vol 66 (3) ◽  
pp. 657-663 ◽  
Author(s):  
L W Tice ◽  
S H Wollman ◽  
R C Carter

The morphology of the tight junction of rat thyroid epithelium was examined in freeze-fractured material fixed in glutaraldehyde and briefly glycerinated. In normal thyroids the overall appearance of this junctional specialization resembled that of other cell types in many respects. Short-term changes in thyroid activity and hypophysectomy for 3 wk did not obviously affect the appearance of tight junctions. Feeding of the goitrogen, thiouracil, which stimulates secretion of thyroid-stimulating hormone, resulted in the appearance of some very narrow and some very wide, tight junctions or sometimes junctions with both wide and narrow regions within the same cell.


1968 ◽  
Vol 46 (3) ◽  
pp. 449-452 ◽  
Author(s):  
A. E. Zimmerman ◽  
C. C. Yip

The effects of increasing or decreasing the endogenous secretion of thyroid-stimulating hormone on the iodinating activity of the rat thyroid gland were investigated. The thyroid iodinating activity of rats on 0.01% propylthiouracil in the drinking water increased linearly for 3 days and reached a maximum of 230 to 240% of the control on or about the fourth day of treatment. The daily injection of thyroxine (10 μg/100 g intraperitoneally) or hypophysectomy resulted in a rapid decrease in the iodinating activity between the first and second day, approaching a basal level by the third day. When the iodinating activity was suppressed for 4 days by daily injections of thyroxine, the activity began to rise on the fifth day after termination of thyroxine treatment.


2010 ◽  
Vol 88 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Lan Wei ◽  
Shen Sun ◽  
Jing Zhang ◽  
Hong Zhu ◽  
Yun Xu ◽  
...  

It is known that severe acute respiratory syndrome (SARS), a severe infectious illness, which caused an epidemic in Asia in 2003, has extensive and complex effects on human organ systems. It has been reported that the serum levels of prolactin (PRL), follicle stimulating hormone (FSH), and luteinizing hormone (LH) of SARS patients are significantly higher than those of control groups, while estradiol (E2), pregnancy hormone (P), and thyroid stimulating hormone (TSH) are considerably lower than those of normal controls. This phenomenon suggests that the adenohypophyseal endocrine cells in SARS patients may be damaged. However, up to now there has been no direct histological investigation on the endocrine cells of patients’ pituitary. Here we investigated the endocrine cells in the adenohypophysis obtained from autopsies of 5 SARS patients. The immunohistochemistry and quantitative image results showed that compared with control cases, both the number of positive cells and the staining intensity of immunoreactivity for growth hormone, TSH, and adrenocorticotrophic hormone in these cells were remarkably decreased, while that of PRL, FSH, and LH were significantly increased in all SARS cases studied. These findings indicated that alterations occurred in the patients’ adenohypophyseal endocrine cells, and these changes were consistent with the serum levels of relevant endocrine hormones reported previously. It appears that changes in these endocrine cells and their hormones are affected by the severity of this new infectious disease.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Leonard Cheung ◽  
Alexandre Daly ◽  
Michelle Brinkmeier ◽  
Sally Ann Camper

Abstract We implemented single-cell RNA sequencing (scRNAseq) technology as a discovery tool to identify factors enriched in differentiated thyrotropes. Thyroid-stimulating hormone (TSH) is produced in the pars distalis of the anterior pituitary (AP) and primarily acts on the thyroid gland to regulate metabolism through T3/T4. However, TSH is also produced by cells in the pars tuberalis (PT), which is comprised of a thin layer of cells that extends rostrally from the pars distalis along the pituitary stalk to the median eminence in the hypothalamus. TSH produced by PT thyrotropes acts on hypothalamic tanycytes to regulate seasonal reproduction. PT thyrotropes likely descend from rostral tip thyrotropes that arise at e12.5 of mouse development, which transcribe the TSH beta subunit (Tshb) without detectable expression of the transcription factor POU1F1. POU1F1 is required for Tshb transcription in thyrotropes of the adenohypophysis, and it acts synergistically with GATA2 to drive cell fate. The molecular mechanisms driving Tshb expression independently of Pou1f1 in PT thyrotropes are unclear. Thyrotropes are the least abundant endocrine cell-type in the pituitary gland. We used genetic labeling and fluorescence-activated cell sorting (FACS) to enrich for thyrotropes for single-cell sequencing. We performed scRNAseq on 7-day-old GFP-positive pituitary cells from Tshb-Cre; R26-LSL-eYFP and intact whole pituitaries, recovering more than 15,000 cells altogether. We observe two distinct populations of cells expressing Tshb. The larger thyrotrope population has approximately twenty fold higher levels of Tshb and five fold higher Cga transcripts than the smaller population, and they are also distinguished by expression of Pou1f1, TSH-releasing hormone receptor (Trhr), and deiodinase 2 (Dio2), consistent with expectations for AP thyrotropes. The smaller thyrotrope population does not express Pou1f1, but those cells are characterized by expression of TSH receptor (Tshr) and melatonin receptor 1A (Mtnr1a), consistent with expectations for PT thyrotropes. They express mildly increased levels of Eya3 and Six1, although these genes are expressed in other cell-types including AP thyrotropes, stem cells, and gonadotropes. They have two-fold higher levels of Gata2 transcripts and uniquely express the transcription factor Sox14. SOX14 is a SoxB2 family transcription factor that counteracts the transcriptional activity of SoxB1 family members, such as Sox2. In conclusion, our scRNAseq has identified novel markers of PT thyrotropes and unveils novel insights into the similarities and differences in the development and function of pituitary thyrotrope subpopulations.


1976 ◽  
Vol 24 (7) ◽  
pp. 846-863 ◽  
Author(s):  
G C Moriarty

The storage sites of the pituitary glycoprotein hormones were identified with the use of electron microscopic immunocytochemical techniques and antisera to the beta (beta) chains of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and thyroid-stimulating hormone (TSH). The TSH cells in normal rats is ovoid or angular and contains small granules 60-160 nm in diameter. In TSH cells hypertrophied 45 days after thyroidectomy, staining is in globular patches in granules or diffusely distributed in the expanded profiles of dilated rough endoplasmic reticulum. The gonadotrophs (FSH and LH cells) exhibited three different morphologies. Type I cells are ovoid with a population of large granules and a population of small granules. Staining for FSHbeta or LHbeta was intense and specific only in the large granules (diameter of 400 nm or greater). Type II cells are angular or stellate and contain numerous secretory granules averaging 200-220 nm in diameter. They predominate during stages in the estrous cycle when FSH or LH secretion is high. Type III cells look like adrenocorticotropin (ACTH) cells in that they are stellate with peripherally arranged granules. They generally stain only with anti-FSHbeta and their staining can not be abolished by the addition of 100 ng ACTH. In preliminary quantitative studies of cycling females, we found that on serial sections FSH cells and LH cells show similar shifts to a more angular population of cells during stages of active secretion. However, the shifts are not in phase with one another. Furthermore, there are at least 1.5 times more FSH cells than LH cells at all stages of the cycle. Our collection of serial cells shows that some cells (usually type I or II) stain for both gonadotropic hormones, whereas others (usually type II or III) contain only one.


1976 ◽  
Vol 21 (6) ◽  
pp. 449-452 ◽  
Author(s):  
Menelaos A. Aliapoulios ◽  
George P. Kacoyanis

1998 ◽  
Vol 157 (3) ◽  
pp. 415-424 ◽  
Author(s):  
RA Metcalfe ◽  
C Findlay ◽  
WR Robertson ◽  
AP Weetman ◽  
S Mac Neil

The thyroid-stimulating hormone (TSH) binds to a receptor which activates adenylate cyclase and elevates cAMP concentration. In addition, effects of TSH on intracellular calcium and inositol phosphate accumulation have been reported. However, the mechanism of TSH-stimulated accumulation of inositol phosphates and elevation of calcium levels is unresolved. Previous work from this laboratory has shown TSH to cause acute transient increases in intracellular calcium in pig, human and FR TL-5 rat thyroid cells as well as in cell transfected with the human TSH receptor (JPO9 cells) in some (but not all) experiments. The aim of this study was to investigate the variability of the calcium response to TSH in JPO9 cells to learn more about the nature of this calcium signal induction. Calcium responses to TSH were determined using the fluorochrome fura-2 in both monolayers of adherent cells and adherent single cells. The responses to a single addition and to repetitive additions of TSH were compared. We also determined the cAMP response to TSH using these two protocols of TSH addition. Our data show that, whereas the cAMP response to TSH is highly predictable and consistent and does not require multiple exposures to TSH, cells were unlikely to respond to TSH with an increase in calcium unless they received multiple challenges with the hormone. A single addition of 10 mU/ml TSH failed to increase calcium in any of 40 single cells examined and in only 4 of 15 monolayers of cells (27%) examined; in contrast, 10 of 12 monolayers eventually responded with an increase in calcium after multiple exposure to TSH and 18 of 67 single cells. Similar data were obtained whether calcium was measured in single cells or in populations of cells. We also demonstrated cooperativity between an adenosine derivative, N6-(L-2-phenylisopropyl)adenosine, and TSH such that their co-administration resulted in a consistent and marked elevation in calcium levels not achieved with either agonist alone. In summary, we suggest that the coupling between the TSH receptor and the intracellular signalling system that leads to activation of intracellular calcium in JPO9 cells requires repetitive stimulation or the influence of other agonists, in contrast with the coupling between the TSH receptor and activation of the adenylate cyclase enzyme.


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