scholarly journals Absence of pituitary prolactin epitopes in immunoreactive prolactin of rat brain.

1991 ◽  
Vol 39 (2) ◽  
pp. 221-224 ◽  
Author(s):  
R E Harlan ◽  
J G Scammell

Immunoreactive prolactin (ir-PRL) in rat brain has been consistently documented. However, the identity of this ir-PRL is controversial. Ir-PRL is defined by its ability to bind to PRL antibodies. All previous studies of brain ir-PRL have used polyclonal antibodies, at least one of which apparently crossreacts with a portion of the proopiomelanocortin molecule. To begin to define the epitopes comprising ir-PRL in the brain, we utilized two monoclonal antibodies (MAb) that recognize pituitary PRL in a variety of species, including rat. Immunocytochemistry was performed on rat brains and pituitary glands using two monoclonal and one polyclonal PRL antibody. Although both MAb immunostained lactotrophs of the rat pituitary gland, neither antibody immunostained cell bodies or neuronal processes in the brain. However, the polyclonal antiserum immunostained lactotrophs and a system of neuronal cell bodies and processes in the brain. Thus, epitopes found in pituitary PRL from several species are not found in ir-PRL in rat brain.

2013 ◽  
Vol 57 (3) ◽  
pp. 387-391
Author(s):  
Radosław Szalak ◽  
Jadwiga Jaworska-Adamu ◽  
Karol Rycerz ◽  
Paweł Kulik ◽  
Marcin Bartłomiej Arciszewski

Abstract Ten adult male chinchillas were used. The localisation of calbindin D28k (CB) was examined with the use of two types of reactions: immunocytochemical peroxidase-antiperoxidase and immunofluorescence staining with a specific monoclonal antibody against CB. Immunocytochemical examination demonstrated the presence of CB-positive neurons in the following layers of all parts the parahippocampal gyrus (PG): marginal, external cellular, middle cellular, and internal cellular, i.e. in entorhinal area, parasubiculum, and presubiculum. Immunofluorescence staining revealed the presence of CB in both Hu C/Dimmunoreactive (IR) neurons and nervous fibers of the PG. CB-IR neuronal cell bodies were moderately numerous (ca. 10% of Hu C/D-IR neurons) and clearly distinguished from the background. Each layer of the brain area consisted of two types of neurons: pyramidal and multiform. Among the second type of neurons, four kinds of morphologically different neuronal subclasses were observed: multipolar, bipolar, round, and Cajal-Retzius cells. It is concluded that the expression of CB in the PG of the chinchilla is species specific and limited to several subclasses of neurons


1997 ◽  
Vol 745 (1-2) ◽  
pp. 1-9 ◽  
Author(s):  
Ambrose A Dunn-Meynell ◽  
Vanessa H. Routh ◽  
Joseph J McArdle ◽  
Barry E Levin

Author(s):  
Milan Stoiljkovic

Local glutamate simulation of intertrigeminal region (ITR) in the lateral pons evoked immediate cardiovascular and respiratory effects proposing its role in central cardiorespiratory control. Since pharmacological studies provided only functional evidence for the existence of glutamate receptors in the ITR and thereby specifying putative neurochemical substrate involved in this control, here we employed immunohistochemistry to examine expression and distribution of NMDA and mGlu1 receptors in this structure. Thirty adult male Sprague-Dawley rats were perfuse-fixed, their brains frozen and cut into sequential series of 20 µm thick sections through the ITR. Immunohistochemistry was performed using polyclonal antibodies against NMDA-NR1, NMDA-NR2A and mGlu1 receptors. Labeled neurons in the ITR were analyzed using light microscope and computerized image analysis system for quantification of relative immunoreactivity as the mean of integrated optical density (IOD), and counting the immunopositive cells. Light microscopic analyses demonstrated NMDA-NR1-immunoreactivity mainly localized in the neuronal cell bodies with sparse distribution on primary dendrites, while NMDA-NR2A-immunoreactivity was basically somatically distributed. The mGlu1-immunoreactivity was moderate and observed both in neuronal bodies and primary dendrites or extracellular matrix suggesting somatodendritic localization. Quantitative analyses of IOD showed very strong expression of NMDA-NR1, weak of NMDA-NR2A and strong-to-moderate expression of mGluR1, with differences in immunostaining signal distribution over rostro-caudal span of the ITR. Counting of immunopositive cells followed similar expression profile. Our data directly confirm the presence of glutamatergic NMDA and mGlu1 receptors in the ITR apparently involved in signaling pathways by which this region modulates cardiorespiratory functions such as blood pressure, heart rate and breathing.


1974 ◽  
Vol 22 (1) ◽  
pp. 7-19 ◽  
Author(s):  
K. L. SIMS ◽  
F. C. KAUFFMAN ◽  
E. C. JOHNSON ◽  
V. M. PICKEL

This study compares the histochemical and microchemical localizations of nicotinamide adenine dinucleotide phosphate (reduced) and nicotinamide adenine dinucleotide (reduced) diaphorases and four nicotinamide adenine dinucleotide phosphate (oxidized)-dependent enzymes (glucose 6-phosphate, 6-phosphogluconate, malate and isocitrate dehydrogenases) in areas of rat metencephalon and spinal cord. For the four nicotinamide adenine dinucleotide phosphate (NADP) enzymes, the pattern of localization following use of a modified tetrazolium procedure was compared with quantitative data obtained by microdissection from the same areas in adjacent sections. Optimal experimental conditions for reaction pH, temperature, substrate, cofactor and divalent cation concentrations were used for both the quantitative analysis following microdissection and the histochemical tetrazolium procedure. Consecutive sections were also examined for isocitrate dehydrogenase (nicotinamide adenine dinucleotide (oxidized)) and nicotinamide adenine dinucleotide (reduced) diaphorase activities in addition to seriatim thionine reference sections. Our results indicate that, within the central nervous system, certain characteristic qualitative differences exist in the distribution of the nicotinamide adenine dinucleotide phosphate (oxidized)- and nicotinamide adenine dinucleotide (oxidized)-dependent dehydrogenase enzymes. Nicotinamide adenine, dinucleotide enzymes are visualized predominantly in neuronal cell bodies or neuropil consisting primarily of neuronal processes; in adjacent sections, NADP enzyme activities are visualized almost exclusively in glial elements with two important exceptions. The first is the cerebellar molecular layer where the results from both micro- and histochemical techniques indicate high levels of the NADP enzymes relative to other dehydrogenases and high activity relative to the levels of these NADP enzymes in other nervous system areas. The second exception occurs in those neuronal groups known to contain high levels of catecholamines; these data are the subject of a companion report.


1998 ◽  
Vol 17 (6) ◽  
pp. 619-630 ◽  
Author(s):  
Devendra Parmar ◽  
Alok Dhawan ◽  
Monika Dayal ◽  
Prahlad K. Seth

Expression of P450 1A1l 1A2 and 2 B1l 2B2 isoenzymes in rat brain was studied by Western blotting, using polyclonal antibodies raised against hepatic P450 1A1l 1A2 and 2B1l 2B2 isoenzymes. In addition, biochemical characterizations of the catalytic activities, pen toxyresorufin O-dealkylation (PROD) and ethoxyre-sorufin O-deethylation (EROD), selective for P450 2B1l 2B2 (PROD) and P450 1A1l 1A2 (EROD), were performed with rat brain microsomes. Control rat brain microsomes did not crossreact with either of the antibodies, whereas microsomes obtained from 3-methylcholanthrene (MC)-pretreated rats revealed significant immunoreactivity with anti-P450 1A1l 1A2. Similar results were observed with phenobarbital (PB)-pretreated rats, with the brain microsomes exhibiting significant immunoreactivity with anti-P450 2B1l 2B2. The induction in the P450 isoenzymes after PB or MC pretreatment was much less in the brain in comparison to the liver. Enzymatic studies indicated that the activities of PROD and EROD were induced in brain 3—4 fold by PB and MC pretreatment, respectively, and were almost completely inhibited on in vitro addition of anti-P450 2B1l 2B2 and 1A1l 1A2. These data demonstrate the expression of P4501A1l 1A2 and 2B1l 2B2 isoenzymes in the brain and indicate that, as in liver, these isoenzymes catalyze EROD and PROD, respectively, in the rat brain.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1728
Author(s):  
Anshuman Sinha ◽  
Rajesh Kushwaha ◽  
Kara Molesworth ◽  
Olga Mychko ◽  
Natallia Makarava ◽  
...  

Phagocytosis is one of the most important physiological functions of the glia directed at maintaining a healthy, homeostatic environment in the brain. Under a homeostatic environment, the phagocytic activities of astrocytes and microglia are tightly coordinated in time and space. In neurodegenerative diseases, both microglia and astrocytes contribute to neuroinflammation and disease pathogenesis, however, whether their phagocytic activities are up- or downregulated in reactive states is not known. To address this question, this current study isolated microglia and astrocytes from C57BL/6J mice infected with prions and tested their phagocytic activities in live-cell imaging assays that used synaptosomes and myelin debris as substrates. The phagocytic uptake by the reactive microglia was found to be significantly upregulated, whereas that of the reactive astrocytes was strongly downregulated. The up- and downregulation of phagocytosis by the two cell types were observed irrespective of whether disease-associated synaptosomes, normal synaptosomes, or myelin debris were used in the assays, indicating that dysregulations are dictated by cell reactive states, not substrates. Analysis of gene expression confirmed dysregulation of phagocytic functions in both cell types. Immunostaining of animal brains infected with prions revealed that at the terminal stage of disease, neuronal cell bodies were subject to engulfment by reactive microglia. This study suggests that imbalance in the phagocytic activities of the reactive microglia and astrocytes, which are dysregulated in opposite directions, is likely to lead to excessive microglia-mediated neuronal death on the one hand, and the inability of astrocytes to clear cell debris on the other hand, contributing to the neurotoxic effects of glia as a whole.


1991 ◽  
Vol 115 (3) ◽  
pp. 731-744 ◽  
Author(s):  
Y Yoshihara ◽  
S Oka ◽  
Y Watanabe ◽  
K Mori

HNK-1 carbohydrate antigen in an epitope expressed commonly in many cell surface adhesion and recognition molecules in the nervous system. We purified and characterized from rat brain a novel phosphatidylinositol (PI)-anchored 150-kD glycoprotein belonging to the HNK-1 family. The molecule (PI-GP150) was detected by combination of PI-specific phospholipase C treatment of brain membranes and Western blot analysis with mAb HNK-1. HNK-1-positive PI-GP150 was purified from the PI-PLC-released materials with three successive chromatographies (Sephacryl S-300, mAb HNK-1-Sepharose 4B, and Mono Q) and proven to be a novel molecule by immunoblot and structural analyses. Polyclonal antibody was raised against PI-GP150 and used to show that (a) PI-GP150 is expressed on the surface of neuronal cell bodies and their processes in culture, and (b) PI-GP150 appears during embryonic development and is present throughout all postnatal life in all brain regions. However, the expression of the HNK-1 epitope on PI-GP150 is regulated in both developmental stage-specific and region-specific manners. In newborn rats, the HNK-1 epitope is expressed on PI-GP150 throughout the brain. The level of HNK-1 epitope on PI-GP150 decreases after postnatal day 7 in hindbrain and becomes completely absent in adult myelencephalon and metencephalon. In contrast, HNK-1 epitope on PI-GP150 was constitutively expressed in telencephalon. Thus, while the HNK-1 carbohydrate epitope is strongly coupled to PI-GP150, its expression can be regulated independently of that of PI-GP150. The differential expression of the HNK-1 epitope at different rostro-caudal axial levels was observed also in other HNK-1 family molecules in brain membranes. These results suggest that the HNK-1 epitope plays an important role in adding region-specific and developmental stage-specific modifications on the function of the cell surface molecules.


1989 ◽  
Vol 257 (2) ◽  
pp. 549-554 ◽  
Author(s):  
F Checler ◽  
H Barelli ◽  
J P Vincent

A monospecific polyclonal antiserum was raised against a recently purified rat brain neurotensin-degrading metallopeptidase. The purified IgG fraction immunoprecipitated the peptidase and inhibited its proteolytic activity. Western blot analyses revealed that the immune fraction recognizes only one protein in rat brain homogenates, and this corresponds closely to the purified enzyme. The IgG displayed a restricted specificity towards the peptidase from murine origin. In the rat, the neurotensin-degrading enzyme was widely distributed throughout peripheral organs with the noticeable exception of the duodenum. In addition, the peptidase was detected in various cell lines or membrane preparations of neural or extraneural origin in which it had been previously characterized by means of biochemical methods. In light of this widespread distribution, the putative role of the peptidase in the metabolism of neuropeptides is discussed.


1979 ◽  
Vol 27 (6) ◽  
pp. 1046-1048 ◽  
Author(s):  
G Pelletier

In an attempt to identify the cells and organellel containing ACTH and beta-lipotropin in the rat brain, an immunocytochemical localization of these two peptides was performed at the electron microscopic level. Both ACTH and beta-lipotropin were localized in dense core vesicles of about 60-80 nm in diameter. Using serial sections, it has been possible to demonstrate that these peptides are contained not only in the same neuronal cell bodies, but also in the same dense core vesicles.


1986 ◽  
Vol 250 (1) ◽  
pp. C95-C102 ◽  
Author(s):  
J. J. Enyeart ◽  
T. Aizawa ◽  
P. M. Hinkle

The dihydropyridine (DHP) Ca2+ agonist Bay K 8644 produced a dose-dependent increase in 45Ca2+ uptake by GH4C1 rat pituitary tumor cells. For agonist concentrations between 10(-9) and 10(-5) M, the enhanced 45Ca2+ uptake was well correlated with simultaneous increases in prolactin (PRL) secretion. Bay K 8644 combined with depolarizing concentrations of KCl produced more than additive effects on net Ca2+ uptake and hormone release. Nisoldipine, a DHP Ca2+ antagonist, competitively blocked Bay K 8644-stimulated 45Ca2+ uptake. This drug also potently inhibited 45Ca2+ uptake triggered by depolarization with KCl (estimated half-maximal inhibiting concentration: 2 nM). Bay K 8644 enhanced PRL secretion from normal rat pituitaries in culture and in a perifusion system. These results indicate that Bay K 8644 is a potent modulator of voltage-sensitive Ca2+ channels of both normal and transformed pituitary cells. In this respect endocrine cell Ca2+ channels resemble those found in heart, smooth muscle, and neuronal cell bodies.


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