Immunohistochemical study of the pars intermedia of the mouse pituitary in different experimental conditions

1976 ◽  
Vol 32 (5) ◽  
pp. 657-658 ◽  
Author(s):  
M. Roux ◽  
M. P. Dubois
Keyword(s):  
Immunohistochemical Study ◽  
Pars Intermedia ◽  
Experimental Conditions ◽  
Mouse Pituitary

The functional significance of glycosylation of proopiomelanocortin in melanotrophs of the mouse pituitary gland

1985 ◽  
Vol 107 (3) ◽  
pp. 365-374 ◽  
Author(s):  
B. G. Jenks ◽  
A. G. H. Ederveen ◽  
J. H. M. Feyen ◽  
A. P. van Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Functional Significance ◽  
Peptide Hormones ◽  
Terminal Region ◽  
Pars Intermedia ◽  
Apparent Effect ◽  
Glycoprotein Precursor ◽  
Tunicamycin Treatment ◽  
Mouse Pituitary

ABSTRACT Pro-opiomelanocortin (POMC) is a glycoprotein precursor for a number of neuropeptides and peptide hormones. The functional significance of the glycosylation of POMC has never been established. Using the antibiotic tunicamycin to block glycosylation of the prohormone in the mouse pars intermedia, we have compared processing of non-glycosylated prohormone with that of glycosylated prohormone in pulse-chase experiments. The peptides produced from non-glycosylated prohormone were shown to be correct cleavage products. Therefore it was concluded that, with the possible exception of peptides from the N-terminal region of the prohormone, the carbohydrate on POMC plays no role in directing cleavage or in protecting the prohormone from random proteolysis. Tunicamycin treatment retarded N-terminal acetylation of melanotrophin but had no apparent effect on acetylation of β-endorphin. The mouse pars intermedia synthesizes two forms of POMC which differ in their degree of glycosylation. Our results indicated that, during secretion, the melanotrophs make no distinction between peptides derived from the two prohormones. J. Endocr. (1985) 107, 365–374

scholarly journals Immunohistochemical study of arachidonate 12-lipoxygenase in porcine tissues.

1989 ◽  
Vol 37 (7) ◽  
pp. 1125-1131 ◽  
Author(s):  
T Maruyama ◽  
N Ueda ◽  
T Yoshimoto ◽  
S Yamamoto ◽  
N Komatsu ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Blood Cells ◽  
Alimentary Tract ◽  
Immunohistochemical Study ◽  
Peripheral Blood Cells ◽  
Experimental Conditions ◽  
12 Lipoxygenase ◽  
Parenchymal Cells ◽  
Lymphatic Organs ◽  
Porcine Tissues

12-Lipoxygenase oxygenates the 12 position of arachidonic acid and produces its 12-hydroperoxy derivative. The enzyme is found in greatest amounts in porcine leukocytes and is distributed widely in various other tissues. An anti-12-lipoxygenase antibody was raised in rabbits with the immunoaffinity-purified enzyme as an antigen and was used in immunohisto- and cytochemical studies on the enzyme, the physiological significance of which remains to be clarified. When peripheral blood cells were examined by immunoelectron microscopy, the enzyme was found in neutrophils and monocytes but was not detected in lymphocytes, platelets, and erythrocytes. In immunostained neutrophils and monocytes the enzyme was localized in the cytosol but was not clearly detected in the plasma membrane, nuclear membrane, endoplasmic reticulum, and other organelles. Several other organs known to contain considerable amounts of 12-lipoxygenase were also investigated immunohistochemically, i.e., alimentary tract (ileum and jejunum), lymphatic organs (spleen, lymph node, and thymus), ovary, lung, liver, and others. In these organs, resident mast cells and granulocytes infiltrating the interstitial tissues were positively immunostained. The enzyme was not detected in parenchymal cells of these organs under our experimental conditions.

Neurosecretory innervation of the pituitary of the eels Anguilla and Conger I. The structure and ultrastructure of the neuro-intermediate lobe under normal and experimental conditions

1966 ◽  
Vol 250 (768) ◽  
pp. 311-327 ◽  
Keyword(s):  
Sea Water ◽  
Synaptic Contact ◽  
Type A ◽  
White Background ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Experimental Conditions ◽  
Synaptic Junctions ◽  
Neurosecretory Fibre ◽  
Structure And Ultrastructure

Three kinds of neurosecretory fibre (Types A 1 , A 2 and B) are present in the neural component of the neuro-intermediate lobe of the eel pituitary. These fibres do not in the main make any direct contact with the pars intermedia cells, but they are separated by only a narrow extravascular channel, into which both elements discharge their products. Type A neurosecretory fibres do, however, make direct synaptic contact with pituicytes which resemble ependyma and surround finger-like extensions of the infundibular recess. That these contacts are functional is indicated by the fact that their frequency is related to changes in the environment. When eels are placed on an illuminated white background the synaptic junctions between Type A 2 neurosecretory fibres and pituicytes are very frequent. Similar synaptic junctions between A 1 fibres and pituicytes were only found in animals which had been recently transferred from fresh water to sea water. A possibility that the pituicytes play some part in a feed-back from the pituitary to the hypothalamus is discussed.

PROTEIN BIOSYNTHESIS IN VITRO BY THE PARS INTERMEDIA OF THE MOUSE PITUITARY GLAND

1977 ◽  
Vol 72 (2) ◽  
pp. 173-179
Author(s):  
H. ISHERWOOD ◽  
V. F. THORNTON
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Protein Biosynthesis ◽  
Pars Intermedia ◽  
Secretory Product ◽  
Posterior Pituitary ◽  
Short Term ◽  
Pituitary Glands ◽  
Mouse Pituitary

SUMMARY During short-term incubations of isolated posterior pituitary glands of the mouse, isotopically labelled amino acids were incorporated into protein by the cells of the pars intermedia. Using labelled leucine, 5–10% of incorporated label was found in a protein (P1), with a molecular weight of about 75000. Protein P1 could be isolated from both fresh and incubated tissue, and was a normal and indeed major, secretory product of the pars intermedia, constituting more than 50% of the protein present.

Cystoid Degeneration of Mouse Pituitary – Ultrastructural Study

1980 ◽  
Vol 38 ◽  
pp. 462-463
Author(s):  
Annette M. Andrews ◽  
Alex M. Cameron ◽  
James W. Townsend ◽  
Winslow G. Sheldon
Keyword(s):  
Electron Microscope ◽  
Toluidine Blue ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Pars Intermedia ◽  
Lead Citrate ◽  
Thin Sections ◽  
Resin Mixture ◽  
Mouse Pituitary ◽  
Two Sides

Pituitaries of 6 C3H/HEJ MTV+ mice about 660 days of age were fixed by immersion in cacodylate-buffered 4% glutaraldehyde, post-fixed in 1% osmium tetroxide, stained en block with aqueous uranyl acetate, dehydrated in a graded series of ethanol solutions, cleared in acetone, and embedded in an Epon-Araldite resin mixture. Semi-thin (1 μm) sections were taken of the entire face of the block, and stained with toluidine blue. Subsequently, thin sections (100 nm) were prepared from mesas of the two sides of the pars distal is and one mesa of the pars intermedia. Thin sections were stained with ethanolic uranyl acetate followed by Sato's lead citrate (1), then examined on a Philips EM201 electron microscope.

SEPARATION OF A LABELLED FRAGMENT FROM PROTEIN SYNTHESIZED IN VITRO BY THE PARS INTERMEDIA OF THE MOUSE PITUITARY GLAND

1977 ◽  
Vol 75 (1) ◽  
pp. 181-182
Author(s):  
H. M. ISHERWOOD ◽  
V. F. THORNTON
Keyword(s):  
Molecular Weight ◽  
Pituitary Gland ◽  
Pars Intermedia ◽  
Biosynthetic Activity ◽  
Cellulose Acetate Electrophoresis ◽  
King's College ◽  
Large Molecular Weight ◽  
Pituitary Glands ◽  
Mouse Pituitary

Department of Anatomy, King's College, London, WC2R 2LS (Received 12 May 1977) The biosynthetic activity of the pars intermedia of the mouse pituitary gland was investigated by studying the fate of labelled amino acids incorporated into relatively large-molecular-weight products (Thornton & Isherwood, 1975). It was reported that label was actively incorporated in vitro into a protein (referred to as 'labelled P1') with a molecular weight of about 75 000 (Isherwood & Thornton, 1977). However, more recent observations suggest that 'labelled P1' is a complex between a protein and a labelled peptide. The purpose of this communication is to give a brief account of some of the findings which led to this conclusion. Full details of the incubation and cellulose acetate electrophoresis procedures are given in Isherwood & Thornton (1977). Posterior pituitary glands from male, Schofield mice were incubated in media containing [3H]leucine and [3H]phenylalanine (50 μCi/ml). In one experiment, posterior

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