scholarly journals Localization of a 16,000-dalton fragment of the common precursor of adrenocorticotropin and beta-lipotropin in the rat and human pituitary gland.

1980 ◽  
Vol 86 (3) ◽  
pp. 825-830 ◽  
Author(s):  
J Guy ◽  
R Leclerc ◽  
G Pelletier
Keyword(s):  
Secretory Granules ◽  
Immunohistochemical Localization ◽  
Pars Intermedia ◽  
Electron Microscope Level ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Common Precursor ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
The Common

To clearly identify cells and organelles containing the common precursor (31,000 dalton) for both adrenocorticotropin (ACTH) and beta-lipotropin (beta-LPH), an immunohistochemical localization of a fragment (16,000 dalton) of the precursor that is not common to beta-LPH and ACTH was conducted in rat and human pituitary glands. With the help of specific antibodies that do not cross-react with beta-LPH and ACTH, the 16,000-dalton fragment was localized in the cells that also produce ACTH and beta-LPH in both the pars distalis and pars intermedia of the rat pituitary. At the electron microscope level, the secretory granules that contain ACTH were also stained for 16,000-dalton fragment. In the human pituitary, the 16,000-dalton fragment was also observed in all the secretory granules of lipocorticotrophs. These results suggest that, after enzymatic cleavage, fragment(s) of the common precursor and/or the whole common precursor remain packaged within the secretory granules with peptides of known activity.

Pituitary Follicular Cells: Their Origin, Possible Function and Fate

1974 ◽  
Vol 32 ◽  
pp. 34-35
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
G. Penz ◽  
C. Ezrin
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Follicular Cells ◽  
Human Pituitary ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Junctional Complexes

Follicular structures, in the rat pituitary, composed of cells joined by junctional complexes and possessing few organelles and few, if any, secretory granules, were first described by Farquhar in 1957. Cells of the same description have since been observed in several species including man. The importance of these cells, however, remains obscure. While studying human pituitary glands, we have observed wide variations in the fine structure of follicular cells which may lead to a better understanding of their morphogenesis and significance.

scholarly journals Purification and characterization of a γ-melanotropin precursor from frozen human pituitary glands

1980 ◽  
Vol 191 (1) ◽  
pp. 125-132 ◽  
Author(s):  
F E Estivariz ◽  
J Hope ◽  
C McLean ◽  
P J Lowry
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Exchange Chromatography ◽  
Precursor Protein ◽  
Tryptophan Residue ◽  
Human Pituitary ◽  
Common Precursor ◽  
Pituitary Glands ◽  
The Common

A new melanocyte-stimulating peptide has been isolated from acid extracts of frozen human pituitary glands by salt/ethanol fractionation, Sephadex G-75 gel filtration and DEAE- and cM-cellulose ion-exchange chromatography. The peptide is glycosylated, has an N-terminal tryptophan residue and an apparent mol.wt. of 16000 as estimated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Its amino acid analysis closely resembles residues Trp-105 to Gln-29 predicted for the common precursor protein of bovine corticotropin and beta-lipotropin by Nakanishi, Inoue, Kita, Nakamura, Chang, Cohen & Numa [(1979) Nature (London) 278, 423-427]. This fragment is expected to have melanotropin activity due to the tetrapeptide -His-Phe-Arg-Trp- (residues -51 to -48) of the predicted sequence of the common precursor. It was found to have a molar potency of 1 × 10(-5) relative to alpha-melanotropin in the frog skin bioassay. These characteristics are consistent with the isolated melanotropin peptide being a non-corticotropin, non-lipotropin peptide of the human common precursor protein of corticotropin and lipotropin. The peptide neither potentiates the adrenal weight-maintenance activity of corticotropin-(1-24)-tetracosapeptide when administered to hypophysectomized rats, nor stimulates release of non-esterified fatty acids from isolated rat epididymal cells. A second N-terminal-tryptophan glycopeptide was also isolated, which had an amino-acid composition similar to that predicted for the bovine common precursor protein, residues Trp-105 to Gly-35.

The corticotrophic cells of the canine pituitary gland in pituitary-dependent hyperadrenocorticism

1983 ◽  
Vol 96 (2) ◽  
pp. 303-309 ◽  
Author(s):  
A. M. McNicol ◽  
H. Thomson ◽  
C. J. R. Stewart
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Pituitary Gland ◽  
Cushing’S Disease ◽  
Cushing's Disease ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Single Entity ◽  
Pituitary Glands ◽  
Corticotrophic Cells

The distribution of specifically stained corticotrophic cells has been studied in the pituitary glands of 11 dogs with pituitary-dependent hyperadrenocorticism. The results suggest that the disease is not a single entity, and that some cases are caused by primary abnormality of the pituitary gland whereas others appear to be the result of dysfunction of the hypothalamus or central nervous system. The patterns correspond closely to those demonstrated in the human pituitary gland in Cushing's disease, and confirm that the canine disease is a useful model for the study of the pathogenesis of the variants of the condition.

Histopathology of pituitary tumours

2011 ◽  
pp. 121-127
Author(s):  
Eva Horvath ◽  
Kalman Kovacs
Keyword(s):  
Mammalian Species ◽  
Cell Types ◽  
Pars Intermedia ◽  
Pars Tuberalis ◽  
Posterior Lobe ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Fibre Network ◽  
Pars Anterior ◽  
A Minor

The human pituitary gland consists of two major components: the adenohypophysis comprising the hormone producing cells of the pars anterior, pars intermedia, and pars tuberalis, and the neurohypophysis, also called pars nervosa or posterior lobe (1). In contrast to most mammalian species, the human gland has no anatomically distinct pars intermedia (2). The exclusively proopiomelanocortin (POMC)-producing cells of the pars intermedia are sandwiched between the anterior and posterior lobes in the majority of mammals, whereas in the human they are incorporated within the pars anterior, thereby constituting the pars distalis (3). The pars tuberalis is a minor upward extension of the adenohypophysis attached to the exterior of the lower pituitary stalk. In this chapter we deal only with adenohypophyseal tumours. Histologically, the adenohypophysis consists of a central median (or mucoid) wedge flanked by the two lateral wings. The hormone-producing cell types are distributed in an uneven, but characteristic manner. The cells are arranged within evenly sized acini surrounded by a delicate but well-defined reticulin fibre network giving the pituitary its distinct architecture (4). In the center of the acini is the long-neglected pituitary follicle composed of the agranular nonendocrine folliculo-stellate cells (5).

scholarly journals ISOLATION AND BIOLOGICAL PROPERTIES OF SECRETORY GRANULES FROM RAT ANTERIOR PITUITARY GLANDS

1969 ◽  
Vol 43 (3) ◽  
pp. 564-574 ◽  
Author(s):  
Allen Costoff ◽  
W. H. McShan
Keyword(s):  
Electron Microscopy ◽  
Anterior Pituitary ◽  
Close Agreement ◽  
Secretory Granules ◽  
Cell Types ◽  
Pituitary Hormones ◽  
Biological Properties ◽  
Single Fraction ◽  
Rat Pituitary ◽  
Pituitary Glands

A method is described for the isolation of secretory granules from rat anterior pituitary glands. The method consists of differential and isopycnic gradient centrifugations, followed by filtration of the zones containing granules on Nuclepore filters to remove mitochondria. Highly purified granules were obtained as indicated by electron microscopy. Major parts of the thyrotropin (TSH) and adrenocorticotropin (ACTH) were recovered in a single fraction of granules as were follicle-stimulating (FSH) and luteinizing (LH) hormones. The somatotropin (STH) and prolactin (LTH) were recovered in separate granule fractions. The major parts of the six different hormones were associated with their respective granule fractions as shown by bioassays specific for each of the hormones. The diameters of granules in sections of intact rat pituitary glands and in isolated pellets were measured, and the means and ranges were in close agreement. These results contribute to the identification of the cell types which produce the different pituitary hormones.

Membranous Layers of the Pituitary Gland: Histological Anatomic Study and Related Clinical Issues

2009 ◽  
Vol 64 (suppl_1) ◽  
pp. ONS1-ONS10 ◽  
Author(s):  
Qi Songtao ◽  
Lu Yuntao ◽  
Pan Jun ◽  
Huang Chuanping ◽  
Shi Xiaofeng
Keyword(s):  
Pituitary Gland ◽  
Lamina Propria ◽  
Internal Carotid ◽  
The Other ◽  
Medial Wall ◽  
Lateral Part ◽  
Fibrous Layer ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Pituitary Glands

Abstract Objective: The purpose of this study was to examine the membranous layers of the human pituitary gland and their relationships with invasive adenomas. Methods: Histological and microdissection techniques were used to study 8 fetal and 10 adult human cadavers, respectively. The distribution of the membranous layers was observed, and their thickness was measured. The results were analyzed histologically and anatomically. Results: In all specimens, the pituitary glands were found to be coated by 2 membranous layers, the inner layer being referred to here as the lamina propria and the outer as the pituitary capsule. In all specimens, the 2 membranes were intact with no histological defects. An interstice or cavity between the 2 layers was found on the surface of the adenohypophysis. However, as these 2 layers got closer and closer to each other, they began to adhere on the surface of the neurohypophysis. The thickness of the pituitary capsule was not constant like that of the lamina propria: the inferolateral part of the capsule was thicker than the other parts. The medial wall of the cavernous sinus (CS) was also a bilayered membrane just like the other CS walls: the 2 layers of the medial CS wall were composed of the lateral part of the pituitary capsule and the fibrous layer. Many fibrous trabeculae arising from this fibrous layer divided the CS into several small venous spaces and connected the internal carotid arteries with the medial wall. Conclusion: The terminology for the 2 membranous layers, the lamina propria and the pituitary capsule, seemed to be more appropriate and representative of the histological features of the pituitary layers. The lateral part of the capsule and the fibrous layer constituted the medial wall of the CS, which has a superior part that is weaker than the thicker inferior part. It is still difficult to postulate the criteria needed to predict CS invasion. However, the distance between the 2 sides of the internal carotid artery might be another predictive criterion to preoperatively diagnose CS invasion by adenomas. Enhanced knowledge of these membranes may be of assistance in finding a useful criterion.

GONADOTROPHINS AND PROLACTIN IN HUMAN PITUITARY GLANDS

1961 ◽  
Vol 36 (2) ◽  
pp. 185-196 ◽  
Author(s):  
A. R. Currie ◽  
J. B. Dekanski
Keyword(s):  
Pituitary Gland ◽  
Lower Yield ◽  
Human Pituitary ◽  
Human Pituitary Gland ◽  
Human Menopausal Gonadotrophin ◽  
Pituitary Glands ◽  
Reference Preparation ◽  
Males And Females ◽  
Human Anterior Pituitary ◽  
Cortisone Therapy

ABSTRACT Human anterior pituitary glands collected at autopsy within 6 hours of death were investigated for gonadotrophic and lactogenic activity. The glands were extracted with 2 % saline and most of the gonadotrophic and lactogenic activity appears to be extracted by this procedure. Little corticotrophic and thyrotrophic activity was found in the extract. The yield of extractable gonadotrophin in the pituitary glands of males and females of varying ages, and the effect of ovariectomy (in two cases) and of cortisone therapy (in one case) on the yield have been investigated. A reference preparation for human menopausal gonadotrophin (HMG20A, Organon) was used as a standard. The amount of stored gonadotrophin increased with advancing age in both sexes. Ovariectomy was associated with a higher yield and cortisone therapy with a lower yield than that shown in pooled pituitary glands from women of the same age group. The ratio of the biological activity of FSH to ICSH in the pituitary glands of men over the age of 50 was about 1 : 1. The method of assay for prolactin was semi-quantitative but there was the same general trend of increased yield with advancing age. The pituitary gland from the case treated with cortisone had the highest yield while ovariectomy appeared to result in a decrease in the stored amount of the hormone. The functional significance of the results of the yield of stored hormones in the human pituitary gland is briefly discussed.

scholarly journals Intracellular sites of proteolytic processing of pro-opiomelanocortin in melanotrophs and corticotrophs in rat pituitary.

1991 ◽  
Vol 39 (6) ◽  
pp. 809-821 ◽  
Author(s):  
S Tanaka ◽  
M Nomizu ◽  
K Kurosumi
Keyword(s):  
Polyclonal Antibody ◽  
Secretory Granules ◽  
Protein A ◽  
Proteolytic Processing ◽  
Pars Intermedia ◽  
Gold Particles ◽  
Melanocyte Stimulating Hormone ◽  
Rat Pituitary ◽  
Almost All ◽  
Electron Lucent

A synthetic peptide (ST-1) corresponding to the cleavage site between ACTH and beta-lipotropic hormone moieties of murine pro-opiomelanocortin (POMC) was constructed and its polyclonal antibody was generated. This antiserum immunoprecipitated only POMC from extracts of AtT-20 cells. Moreover, an antiserum raised against porcine ACTH immunoprecipitated both ACTH[1-39] and POMC. When ultra-thin frozen sections of melanotrophs in rat pars intermedia were immunolabeled with anti-ST-1 followed by protein A-gold, gold particles indicating the presence of POMC were selectively found in the electron-dense secretory granules in the Golgi area. In addition, the immunolabeling was also observed in the cisternae of the Golgi apparatus and rough endoplasmic reticulum. In contrast, with a polyclonal antibody specific for alpha-melanocyte-stimulating hormone the gold particles were found exclusively in the electron-lucent secretory granules, with none seen in the electron-dense secretory granules. With anti-ACTH serum, gold particles were observed in the electron-dense and -lucent secretory granules. In corticotrophs in the pars distalis, many gold particles indicating the presence of POMC were observed in the Golgi and peripheral secretory granules, but the percentage of immunolabeling in the peripheral secretory granules varied from cell to cell. On the other hand, ACTH immunolabeling was found in almost all the secretory granules. This finding suggests that the processing of POMC in corticotrophs might occur in the relatively peripheral granules. These results suggest that the intracellular sites of POMC processing are somewhat different between melanotrophs and corticotrophs in the pituitary.

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