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Results 401 - 450 of 1801
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Radian S - - 2003
Somatotroph and thyrotroph pituitary cells share a common precursor cell expressing the transcription factor Pit1 in ontogeny. Cells expressing both thyrotropin (TSH) and growth-hormone (GH) are found in adult rat pituitary and in human pituitary adenomas in acromegaly, and these tumors contain both thyrotropin-releasing hormone (TRH) and the TRH receptors ...
Laiz-Carrión Raul - - 2003
The distribution and ontogeny of adenohypophyseal cells have been studied in the pituitary gland of embryos, larvae, and juveniles of the clupeid American shad (Alosa sapidissima) using immunocytochemical techniques. In juvenile specimens, adenohypophysis was composed of rostral pars distalis (RPD), formed by cavities lined by prolactin (PRL), adrenocorticotropic hormone (ACTH), ...
Noda Takahiro - - 2003
Hormone-producing cells in the rat anterior pituitary gland are not randomly distributed; rather, there are specific topographic affinities among five cell types (Noda et al., Acta Histochem. Cytochem. 2001;34:313-319). In this study we reconstructed these affinities, at least partially, in primary monolayer culture. Pituitary cells collected from adult male rats ...
Shimizu Akio - - 2003
Two distinct types of gonadotrophs, FSH (GtH I) cells and LH (GtH II) cells, were immunocytochemically identified from mummichog (Fundulus heteroclitus; Cyprinodontiformes, Acanthopterygii) pituitary using antisera raised against synthetic fragment peptides of FSHbeta and LHbeta. Both cell types were abundant during the spawning period (spring and early summer) and decreased ...
Sánchez Cala F - - 2003
The adenohypophysis of the greater weever fish (Trachinus draco) was studied using histochemical and immunocytochemical methods. The adenohypophysis comprised the rostral pars distalis (RPD), the proximal pars distalis (PPD), and the pars intermedia (PI). Neurohypophysis showed a patent hypophyseal stalk which was divided into several branches intermingled with the adenohypophysis. ...
Wada Michihito - - 2003
Parathyroid cell hyperplasia is commonly observed in patients with chronic renal insufficiency and largely accounts for refractory secondary hyperparathyroidism. Calcimimetics are newly synthesized compounds that activate a calcium receptor on the parathyroid cell and can suppress parathyroid hormone secretion. The calcimimetic compound AMG 073 has been examined in clinical trials, ...
Lewy Hadas - - 2003
The number of pituitary cells, their size, hormonal content and release and response to external cues varies between day and night and during the estrus cycle. Previous studies have demonstrated that pituitary cells proliferate rhythmically and that estradiol (E(2)) is a mitogen of alpha T3 cells. We, therefore, studied the ...
Nuñez Lucía - - 2003
The existence of cells storing and secreting two different anterior pituitary (AP) hormones (polyhormonal cells) or responding to several hypothalamic releasing hormones (HRHs) (multiresponsive cells) has been reported previously. These multifunctional cells could be involved in paradoxical secretion (AP hormone secretion evoked by a non-corresponding HRH) and transdifferentiation (phenotypic switch ...
Zitnan D - - 2003
Pre-ecdysis- and ecdysis-triggering hormones (PETH and ETH) from endocrine Inka cells initiate ecdysis in moths and Drosophila through direct actions on the central nervous system (CNS). Using immunohistochemistry, we found Inka cells in representatives of all major insect orders. In most insects, Inka cells are numerous, small and scattered throughout ...
Hassanin Amin - - 2003
The adverse effect of estrogenic chemicals on luteinizing hormone-immunoreactive (LH-ir) cells in the adenohypophysis of common carp (Cyprinus carpio) was examined using immunocytochemical and morphometric methods. Adult male fish were collected from two contaminated sites (Ishizu and Wada Rivers) and from a control pond at Agriculture, Food and Environmental Sciences, ...
Ishikawa Takaki - - 2003
Healthy subjects 40 years old were used as controls in a study of stellate cells (S-100 protein-containing cells, or S-100 cells) in subjects with chronic alcoholism and fatty liver or fatty cirrhosis. S-100 cells were sparsely found in the adenohypophysis of control subjects, and these cells sometimes formed small clusters. ...
Carretero José - - 2003
Lactation is a physiological process associated with hyperactivity of hypophyseal prolactin-producing cells. It is known that the percentage of these cells is increased during lactation, although there are discrepancies in the reports regarding the mechanisms responsible for increasing the number of prolactin cells. In order to analyse whether this increase ...
van Kerkhof Peter - - 2003
The number of growth hormone receptors (GHRs) per cell are regulated and this feature plays a major role in the hormone responsiveness of the body. We previously observed in transfected Chinese hamster lung cells that GHR availability is determined by three factors: endocytosis (75%), shedding (10%), and other undetermined mechanisms ...
Chapman Lee P - - 2003
Annexin 1 (ANXA1) has a well-demonstrated role in early delayed inhibitory feedback of glucocorticoids in the pituitary. ANXA1 is located in folliculo-stellate (FS) cells, and glucocorticoids act on these cells to externalize and stimulate the synthesis of ANXA1. However, ANXA1 lacks a signal sequence so the mechanism by which ANXA1 ...
Franklin J - - 2003
Gonadotrophin-releasing hormone receptors (GnRH-Rs) are found in cancers of reproductive tissues, including those of the prostate, and gonadotrophin-releasing hormone (GnRH) can inhibit growth of cell lines derived from such cancers. Although pituitary and extra-pituitary GnRH-R transcripts appear identical, their functional characteristics may differ. Most extra-pituitary GnRH-Rs have low affinity for ...
Norris A J - - 2003
Real-time imaging of the GH gene promoter linked to luciferase in living pituitary cells has revealed surprising heterogeneity and variety of dynamic patterns of gene expression. Cells treated with either forskolin or thyroid hormone generated a consistent and characteristic temporal response from cell populations, but detailed analysis of individual cells ...
Bilezikjian Louise M - - 2003
Folliculostellate cells of the anterior pituitary are postulated to be an important source of factors, such as follistatin, that regulate pituitary function by intercellular communication. To gain further insight into the function of this cell type, folliculostellate cells were enriched from cultured rat anterior pituitary cells, and an immortalized cell ...
Herzog Wiebke - - 2003
Formation of the adenohypophysis in mammalian embryos occurs via an invagination of the oral ectoderm to form Rathke's pouch, which becomes exposed to opposing dorsoventral gradients of signaling proteins governing specification of the different hormone-producing pituitary cell types. One signal promoting pituitary cell proliferation and differentiation to ventral cell types ...
Carretero, J.
Pituitary VIP levels and pituitary VIP-expressing cell numbers are increased in hypothyroidism, but the regulating role of TRH as regards morphological changes remains obscure. In order to determine whether TRH is involved in regulating the maintenance of pituitary VIP-expressing cells and its cellular proliferation a double immunocytochemical study for VIP ...
Black David R - - 2003
Effects of radiofrequency electromagnetic fields (RFEMF) on the pituitary adrenocortical (ACTH), growth (GH), and thyroid (TSH) hormones have been extensively studied, and there is coherent research on reproductive hormones (FSH and LH). Those effects which have been identified are clearly caused by heating. The exposure thresholds for these effects in ...
Siawrys Gabriela - - 2003
The direct effects of alpha- and beta-adrenergic agents on PRL and beta-endorphin (beta-END) secretion in vitro by porcine pituitary cells have been investigated. Pituitary glands were obtained from mature gilts, which were ovariectomised (OVX) one month before slaughter. Ovariectomised gilts, assigned to four groups, were primed with: (1) vehicle (OVX); ...
Najvirtová Miroslava - - 2003
Cell swelling causes an immediate secretory response in various cell types. Induced secretion possesses some unique features suggesting the involvement of a specific signal transduction pathway. The effect of 10-20 microM GdCl3, 100 microM HgCl2, 1-100 microM indomethacin and 1-20 microM nordihydroguaiaretic acid (NDGA) on cell swelling-induced hormone secretion (isosmotic ...
Graham E Scott - - 2002
This study demonstrates the presence of two prolactin-releasing (PR) factors in media conditioned by primary pars tuberalis cells prepared from dispersed pars tuberalis tissue. One factor was identified as thyrotropin-releasing hormone (TRH) on the basis of immunoreactivity and following purification by high-performance liquid chromatography and mass spectrometry. The origin of ...
Campbell Celeste H - - 2002
We used modified immunocytochemical conditions to quantify a membrane form of estrogen receptor-alpha (mERalpha) in a rat pituitary tumor cell line, GH3/B6/F10. We studied the regulation of mERalpha vs. levels of intracellular ERalpha (iERalpha) using our 96-well plate immunoassay. The anti-ERalpha antibody C542 was used to label the ERalpha (via ...
Westphal Heiner - - 2002
The pituitary gland with its distinct populations of hormone-producing cells is formed from precursor cells that are created when epithelial cells from the prospective diencephalon about the roof of the oral cavity during early development of the mammalian embryo. Successive steps of assembly during development lead from a rudimentary pouch ...
Kölle Sabine - - 2003
Pituitary LH and FSH are known to be the major regulators of ovarian function. In the last few years, however, there has been evidence that growth hormone (GH) is also involved in ovarian regulation. Therefore, the aim of our study was to elucidate the mechanisms of GH action during in ...
Szabó E - - 2002
The presence of pituitary adenylate cyclase activating polypeptide (PACAP) was previously demonstrated in the anterior pituitary by radioimmunoassay, immunohistochemistry, and reverse transcript-polymerase chain reaction (RT-PCR). With the use of cell immunoblot assay (CIBA), when the pituitary cells were cultured on nitrocellulose membrane, the release of PACAP by individual anterior pituitary ...
Alves Leandro M - - 2002
Although some studies have shown a possible modulation of the stroma on the hormonal secretion, it is not clear as to what are the requirements for these cellular interactions. In the present work, a homogeneous and continuous lineage of rat adenohypophysis stromal cells (APS9 cells) obtained from rat adenohypophysis primary ...
Chapman Lee - - 2002
Our recent studies on rat pituitary tissue suggest that the annexin I-dependent inhibitory actions of glucocorticoids may not be exerted directly on endocrine cells but indirectly via folliculo-stellate (FS) cells. FS cells contain glucocorticoid receptors and abundant annexin I. We have studied the localization of annexin I in FS cells ...
Yin Ping - - 2002
Estrogen affects apoptotic cell death in estrogen-responsive tissues. The purpose of the present study was to examine dynamic changes in apoptotic cell death in the anterior pituitary gland during the estrous cycle and to investigate neuroendocrine regulation of these changes in cycling female rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling ...
Hill Rena M - - 2002
Serine proteases play essential roles in a wide variety of cellular processes in endocrine cells. There is a growing interest in the roles of serine protease inhibitors, or serpins, as key regulators of their activity. We have cloned two neuroserpin cDNAs from a rat pituitary cDNA library and confirmed tissue ...
Taniguchi Yutaka - - 2002
Studies on the proliferation and differentiation of the cells in the rat anterior pituitary were reviewed. The mitotic rate of anterior pituitary is low in the control adult animal, but it increased by stimulation, such as by ablation of the target organ. A high mitotic rate was also reported during ...
Raetzman Lori T - - 2002
Deficiencies in the homeobox transcription factors LHX4 and PROP1 cause pituitary hormone deficiency in both humans and mice. Lhx4 and Prop1 mutants exhibit severe anterior pituitary hypoplasia resulting from limited differentiation and expansion of most specialized cell types. Little is known about the mechanism through which these genes promote pituitary ...
Edwards Lincoln P - - 2002
Intracellular, ratiometric microfluorimetry with fura-2 reveals that low doses of Portuguese Man-of-war (Physalia physalis) venom cause a linear increase in intracellular calcium accumulation by cultured L-929 cells. The influx of calcium is preceded by a lag period that is relatively independent of venom concentration, except at very low concentrations. Electron ...
Fauquier Teddy - - 2002
The traditional view holds that the anterior pituitary is an endocrine gland with a complex and heterogeneous distribution of cells throughout the parenchyma. Thus, a long-distance mode of intraorgan communication is not usually taken into account in our understanding of pituitary functioning. However, recent in situ pituitary studies have begun ...
Nardi J B - - 2002
Endodermal or midgut cells have only recently been recognized as the site of pheromone synthesis in bark beetles. Midgut cells are not only specialized for digestion, but they have also been recruited to form isoprenoid compounds that function as pheromone components in Ips pini and Dendroctonus jeffreyi. Male bark beetle ...
Pilar García Hernández M - - 2002
Two antisera against the follicle-stimulating hormone-like gonadotropin (FSH) of Mediterranean (M.) yellowtail, anti-My FSHa and anti-My FSHb, were obtained. Anti-My FSHa serum specifically recognized FSH cells and did not react with any other pituitary cell type, while anti-My FSHb serum recognized the alpha-subunit of the pituitary glycoprotein hormones and immunostained ...
Levy A - - 2002
A complete inventory of pituitary trophic responses depends on precise estimates of mitotic activity and apoptotic events, and accurate characterization and quantification of pituitary cell subtypes irrespective of previous and current physiological demand. For a discrete structure that has been so extensively studied, it is disappointing but perhaps not surprising ...
Ozawa H - - 2002
In the pituitary gland, annexin-1 (lipocortin-1) located in folliculo-stellate (FS) cells has been advocated as one of the candidates for paracrine agents produced by FS cells that modulate the release of pituitary hormones. However, the expression and distribution pattern of annexin-1 in FS cells under different circulating corticosteroid conditions has ...
Kinzler Eric R ER McArdle Laboratory for Cancer Research, University of Wisconsin Medical School, Madison, WI 53706, - - 2002
All herpesviruses examined to date encode a heterodimeric envelope complex consisting of glycoprotein H (gH) and glycoprotein L (gL); however, co-expression of human cytomegalovirus (HCMV) gH and gL is not sufficient to reconstitute the high molecular weight complex seen in infected cells. Previously, we showed that HCMV encodes a third ...
Kakeya Tomoshi - - 2002
Several reports have indicated that prolactin-secreting cells (PRL cells) are generated from growth hormone-secreting cells (GH cells). We have shown that treatment with a combination of epidermal growth factor (EGF), insulin, and estradiol-17beta (E (2)) induces the appearance of PRL cells in pituitary tumor GH3 cells. The aim of the ...
Horvath Eva - - 2002
Ultrastructural and immunocytochemical observations of pituitary folliculo-stellate cells (FSC) in a large series of adenomatous and nontumorous human pituitaries led to the following conclusions: (1) The endocrine cells of both the nontumorous and the adenomatous pituitary are capable of transforming into FSC while changing from endocrine to nonendocrine phenotype. (2) ...
Arakawa Yukio - - 2002
We developed a sensitive and specific immunoassay system for human neuronal nitric oxide synthase (hnNOS) using synthetic hnNOS(998-1024) peptide and anti-hnNOS(998-1024) antibody. The novel antibody and radioimmunoassay system revealed a typical nNOS protein in human neuroblastoma NB-OK-1 cell (160 kDa, 180 fmol/10(6) cells). The kinetic parameters of the enzyme were ...
Tiwary Basant K - - 2002
Gonadotropin-releasing hormone (GnRH), a regulator of gonadal maturation in vertebrates, is primarily secreted by neurosecretory cells of the pre-optic area (POA) in the forebrain of teleosts. GnRH-immunoreactive (GnRH-ir) cells of this area demonstrate positive correlation in number and size of soma with gonadal maturity and directly innervate the pituitary in ...
Zeitler Philip - - 2002
GHRH, in addition to stimulating the release of growth hormone (GH) from the pituitary, is a trophic factor for pituitary somatotrophs. Growth hormone-releasing hormone is also expressed in the gonads, gastrointestinal tract, pancreas, thymus, and lymphocytes, as well as in tumors of the pancreas, lung, central nervous system, and breast. ...
Cheong Kwang Ho - - 2002
We investigated whether yeast signals could regulate hormone processing in mammalian cells. Chmeric genes coding for the prepro region of yeast alpha-factor and the functional hormone region of anglerfish somatostatin was expressed in rat pituitary GH(3) cells. The nascent prepro-alpha-factor-somatostatin peptides disappeared from cells with a half-life of 30 min, ...
George-Téllez R - - 2002
In the mammalian cell nucleus, splicing factors are distributed in nuclear domains known as speckles or splicing factor compartments (SFCs). In cultured cells, these domains are dynamic and reflect transcriptional and splicing activities. We used immunofluorescence and confocal microscopy to monitor whether splicing factors in differentiated cells display similar features. ...
Hiyama H - - 2002
p21/WAF1 blocks cell cycle progression through inhibition of cyclin/cyclin-dependent kinases (cdks) complexes and, simultaneously, has been associated with cell cycle exit and the process of differentiation. In this series, the expression of p21/WAF1 was assessed immunohistochemically in 47 cases of pituitary adenomas in relation to endocrine activity and cell proliferation. ...
Ishikawa Tomoko - - 2002
Despite a multitude of reports on the classification and distribution of anterior pituitary cells, no previous study has attempted to obtain the three-dimensional (3D) and computer-graphic distribution pattern of each cell type in the whole pituitary. Therefore, we mapped the anterior pituitary cells of the house musk shrew ( Suncus ...
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