The role of prostanoids in ozone-induced changes in airway responsiveness: receptor activation-specific prostanoid release

1998 ◽  
Vol 5 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Helena J.M van Hoof ◽  
Freek J Zijlstra ◽  
Hans-Peter Voss ◽  
Corné J.A.M Tak ◽  
Leendert van Bree ◽  
...  
Keyword(s):  
Receptor Activation ◽  
Airway Responsiveness ◽  
Induced Changes

Role of C fibers in physiological responses to ozone in rats

1995 ◽  
Vol 78 (5) ◽  
pp. 1757-1763 ◽  
Author(s):  
M. Jimba ◽  
W. A. Skornik ◽  
C. R. Killingsworth ◽  
N. C. Long ◽  
J. D. Brain ◽  
...  
Keyword(s):  
Core Body Temperature ◽  
Dynamic Compliance ◽  
Airway Responsiveness ◽  
Pulmonary Mechanics ◽  
Neonatal Rats ◽  
Implanted Electrodes ◽  
C Fibers ◽  
Induced Changes ◽  
Core Body

The purpose of this study was to evaluate the role of C fibers in airway responsiveness after exposure to ozone (O3) in rats. The role of C fibers in the decreases in heart rate (HR) and core body temperature (Tc) that occur after inhalation of O3 was also examined. Neonatal rats were treated with capsaicin (Cap) or the vehicle used to dissolve capsaicin (Veh). Cap has been shown to cause permanent destruction of C fibers. When they reached adulthood, conscious minimally restrained rats were exposed to 2 ppm O3 or to air for 3 h. Two hours after the cessation of exposure, rats were anesthetized and instrumented for the measurement of pulmonary mechanics and airway responsiveness to inhaled aerosolized methacholine. O3 had no effect on baseline pulmonary conductance (GL) in either Veh or Cap rats but did cause a decrease in dynamic compliance (Cdyn) in Cap rats (P < 0.05). In Cap rats, O3 exposure caused a marked increase in airway responsiveness; the doses of inhaled aerosolized methacholine required to decrease GL and Cdyn by 50% were 6.5-fold and 9.8-fold lower in O3-compared with air-exposed rats (P < 0.005). In contrast, in Veh rats, O3 did not alter responsiveness. During O3 exposure, there was a profound, almost 50%, decrease in HR as measured with implanted electrodes. A decrease in Tc (measured with a rectal probe) of approximately 2.5 degrees C also occurred during O3 exposure. There was no significant effect of Cap pretreatment on the magnitude of these O3-induced changes in HR and Tc. Our results are consistent with the hypothesis that C fibers act to inhibit the development of hyperresponsiveness elicited by O3 inhalation but do not contribute to O3-induced changes in HR or Tc.

Role of NO and cytochrome P-450-derived eicosanoids in ET-1-induced changes in intrarenal hemodynamics in rats

2000 ◽  
Vol 279 (6) ◽  
pp. R2132-R2141 ◽  
Author(s):  
H. C. Hercule ◽  
A. O. Oyekan
Keyword(s):  
Blood Flow ◽  
Receptor Antagonist ◽  
Receptor Activation ◽  
Dependent Manner ◽  
Medullary Blood Flow ◽  
Arterial Blood ◽  
Induced Changes ◽  
Renal Vascular ◽  
Cytochrome P 450

Endothelin-1 (ET-1) produces potent renal effects that we have previously shown to be dependent on cytochrome P-450 (CYP450) metabolites of aracidonic acid (24) This study evaluated the role of these metabolites in the effects produced by ET-1 on renal blood flow (RBF), cortical blood flow (CBF), medullary blood flow (MBF), and mean arterial blood pressure (MBP). ET-1 (20–200 pmol/kg) increased MBP, renal vascular resistance (RVR), and MBF but reduced CBF and RBF in a dose-dependent manner. The decreases in CBF and RBF, and increases in MBP and RVR were blunted by BMS-182874, an ET a receptor antagonist or BQ-788, an ET b receptor antagonist. Similarly, indomethacin, an inhibitor of cyclooxygenase activity, or 12,12-dibromododecenoic acid (DBDD), a CYP450-dependent inhibitor of production of 20-hydroxyeicosatetraenoic acid (20-HETE), blunted these effects. ET-3 elicited dose-related reduction in CBF and increase in MBF. Indomethacin accentuated the reduction in CBF and attenuated the increase in MBF, as did DBDD. ET-1-induced increase in MBF was attenuated by BQ-788, N ω-nitro-l-arginine methyl ester (l-NAME), an inhibitor of nitric oxide (NO) synthesis, indomethacin, or DBDD. DBDD inhibited the hemodynamic effects ofl-NAME. Miconazole, the inhibitor of CYP450-dependent epoxygenase activity, was without effect. These results indicate that hemodynamic changes produced by ET-1 are mediated by vasoconstrictor prostanoids and/or prostanoid-like substances, possibly, 20-HETE via activation of ET a and ET b receptors. However, the increase in MBF is mediated by vasodilator prostanoids or by NO via ET b receptor activation.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Cannabinoid-induced changes in the immune system: The role of microRNAs

2021 ◽  
Vol 98 ◽  
pp. 107832
Author(s):  
Hirva K. Bhatt ◽  
Dana Song ◽  
Gyen Musgrave ◽  
P.S.S. Rao
Keyword(s):  
Immune System ◽  
Induced Changes

scholarly journals Space Radiation-Induced Alterations in the Hippocampal Ubiquitin-Proteome System

2021 ◽  
Vol 22 (14) ◽  
pp. 7713
Author(s):  
Alyssa Tidmore ◽  
Sucharita M. Dutta ◽  
Arriyam S. Fesshaye ◽  
William K. Russell ◽  
Vania D. Duncan ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Memory Performance ◽  
Space Radiation ◽  
Label Free ◽  
Proteomic Profiling ◽  
Neurocognitive Deficits ◽  
Male Wistar Rats ◽  
Radiation Induced ◽  
Induced Changes

Exposure of rodents to <20 cGy Space Radiation (SR) impairs performance in several hippocampus-dependent cognitive tasks, including spatial memory. However, there is considerable inter-individual susceptibility to develop SR-induced spatial memory impairment. In this study, a robust label-free mass spectrometry (MS)-based unbiased proteomic profiling approach was used to characterize the composition of the hippocampal proteome in adult male Wistar rats exposed to 15 cGy of 1 GeV/n 48Ti and their sham counterparts. Unique protein signatures were identified in the hippocampal proteome of: (1) sham rats, (2) Ti-exposed rats, (3) Ti-exposed rats that had sham-like spatial memory performance, and (4) Ti-exposed rats that impaired spatial memory performance. Approximately 14% (159) of the proteins detected in hippocampal proteome of sham rats were not detected in the Ti-exposed rats. We explored the possibility that the loss of the Sham-only proteins may arise as a result of SR-induced changes in protein homeostasis. SR-exposure was associated with a switch towards increased pro-ubiquitination proteins from that seen in Sham. These data suggest that the role of the ubiquitin-proteome system as a determinant of SR-induced neurocognitive deficits needs to be more thoroughly investigated.

scholarly journals The Effect of Dual Language Activation on L2-Induced Changes in L1 Speech within a Code-Switched Paradigm

Languages ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 114
Author(s):  
Ulrich Reubold ◽  
Sanne Ditewig ◽  
Robert Mayr ◽  
Ineke Mennen
Keyword(s):  
Dual Language ◽  
Native Speakers ◽  
Predictor Variable ◽  
Predictor Variables ◽  
Acoustic Measures ◽  
Before And After ◽  
Language Activation ◽  
Dual Activation ◽  
Induced Changes

The present study sought to examine the effect of dual language activation on L1 speech in late English–Austrian German sequential bilinguals, and to identify relevant predictor variables. To this end, we compared the English speech patterns of adult migrants to Austria in a code-switched and monolingual condition alongside those of monolingual native speakers in England in a monolingual condition. In the code-switched materials, German words containing target segments known to trigger cross-linguistic interaction in the two languages (i.e., [v–w], [ʃt(ʁ)-st(ɹ)] and [l-ɫ]) were inserted into an English frame; monolingual materials comprised English words with the same segments. To examine whether the position of the German item affects L1 speech, the segments occurred either before the switch (“He wants a Wienerschnitzel”) or after (“I like Würstel with mustard”). Critical acoustic measures of these segments revealed no differences between the groups in the monolingual condition, but significant L2-induced shifts in the bilinguals’ L1 speech production in the code-switched condition for some sounds. These were found to occur both before and after a code-switch, and exhibited a fair amount of individual variation. Only the amount of L2 use was found to be a significant predictor variable for shift size in code-switched compared with monolingual utterances, and only for [w]. These results have important implications for the role of dual activation in the speech of late sequential bilinguals.

Nitric oxide decreases lung liquid production via guanosine 3′,5′-cyclic monophosphate

2001 ◽  
Vol 280 (5) ◽  
pp. L923-L929 ◽  
Author(s):  
James J. Cummings ◽  
Huamei Wang
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Epithelium ◽  
Fetal Sheep ◽  
Cgmp Analog ◽  
Pulmonary Arterial ◽  
Series Of Experiments ◽  
Lung Liquid ◽  
Tracer Dilution ◽  
Induced Changes

We studied the role of cGMP in nitric oxide (NO)-induced changes in lung liquid production ( J v ) in chronically instrumented fetal sheep. Forty-five studies were done in which J v was measured by a tracer dilution technique. Left pulmonary arterial flow (Qlpa) was measured by a Doppler flow probe. There were two series of experiments. In the first, we gave 8-bromo-cGMP, a cGMP analog, by either the pulmonary vascular or intraluminal route; in the second, we used agents to inhibit or enhance endogenous cGMP activity. When infused directly into the pulmonary circulation, 8-bromo-cGMP significantly increased Qlpa but had no effect on J v. Conversely, when instilled into the lung liquid, 8-bromo-cGMP had no effect on Qlpa but significantly reduced J v. Inhibition of guanylate cyclase activity with methylene blue totally blocked, whereas phosphodiesterase inhibition with Zaprinast significantly enhanced, the effect of instilled NO on J v. Thus the reduction in lung liquid caused by NO appears to be mediated by cGMP, perhaps through a direct effect on the pulmonary epithelium.

scholarly journals An autoantibody directed against human thrombin anion-binding exosite in a patient with arterial thrombosis: effects on platelets, endothelial cells, and protein C activation

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 1843-1850 ◽  
Author(s):  
E Arnaud ◽  
M Lafay ◽  
P Gaussem ◽  
V Picard ◽  
M Jandrot-Perrus ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Arterial Thrombosis ◽  
Protein C ◽  
Receptor Activation ◽  
Anion Binding ◽  
Thrombin Receptor ◽  
Cell Functions ◽  
Human Thrombin

Abstract An autoantibody, developed by a patient with severe and recurrent arterial thrombosis, was characterized to be directed against the anion- binding exosite of thrombin, and inhibited all thrombin interactions requiring this secondary binding site without interfering with the catalytic site. The effect of the antibody was studied on thrombin interactions with platelets and endothelial cells from human umbilical veins (HUVEC). The autoantibody specifically and concentration- dependently inhibited alpha-thrombin-induced platelet activation and prostacyclin (PGI2) synthesis from HUVEC. It had no effect when gamma- thrombin or the thrombin receptor activation peptide SFLLR were the inducers. The effect of the antibody on protein C activation has been studied. The antibody blocked the thrombin-thrombomodulin activation of protein C. The inhibition of the activation was maximal with a low concentration of thrombomodulin. The fact that the autoantibody inhibited concentration-dependent alpha-thrombin-induced platelet and endothelial cell functions emphasizes the crucial role of the anion- binding exosite of thrombin to activate its receptor. In regard to the pathology, the antibody inhibited two vascular processes implicated in thrombin-antithrombotic functions, PGI2 secretion, and protein C activation, which could be implicated in this arterial thrombotic disease.

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