scholarly journals Neurochemical Plasticity of the Coeliac-Superior Mesenteric Ganglion Complex Neurons Projecting to the Prepyloric Area of the Porcine Stomach following Hyperacidity

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Katarzyna Palus ◽  
Jarosław Całka

This study was designed to determine neurochemical properties of the coeliac-superior mesenteric ganglion (CSMG) neurons supplying the prepyloric area of the porcine stomach in physiological state and following experimentally induced hyperacidity. To localize sympathetic neurons innervating the studied area of stomach, the neuronal retrograde tracer Fast Blue (FB) was applied to control animals and hydrochloric acid infusion (HCl) groups. After 23 days, animals of the HCl group were reintroduced into a state of general anesthesia and intragastrically given 5 mL/kg of body weight of 0.25 M aqueous solution of hydrochloric acid. On the 28th day, all animals were sacrificed. The CSMG complexes were then collected and processed for double-labeling immunofluorescence. In the control animals, FB-positive perikarya displayed immunoreactivity to tyrosine hydroxylase (TH), dopamineβ-hydroxylase (DβH), neuropeptide Y (NPY), and galanin (GAL). Experimentally induced gastric hyperacidity changed the neurochemical phenotype of the studied neurons. An upregulated expression of GAL and NPY and thede novosynthesis of neuronal nitric oxide synthase (nNOS) and leu5-enkephalin (LENK) as well as downregulated expression of TH and DβH in the stomach-projecting neurons were observed. These findings enrich existing knowledge about the participation of these active substances in adaptive mechanism(s) of the sympathetic neurons during pathological processes within the gastrointestinal tract.

2006 ◽  
Vol 80 (3) ◽  
pp. 1181-1190 ◽  
Author(s):  
Heather B. Nelson ◽  
Hengli Tang

ABSTRACT An intimate relationship between hepatitis C virus (HCV) replication and the physiological state of the host liver cells has been reported. In particular, a highly reproducible and reversible inhibitory effect of high cell density on HCV replication was observed: high levels of HCV RNA and protein can be detected in actively growing cells but decline sharply when the replicon cells reach confluence. Arrested cell growth of confluent cells has been proposed to be responsible for the inhibitory effect. Indeed, other means of arresting cell growth have also been shown to inhibit HCV replication. Here, we report a detailed study of the effect of cell growth and confluence on HCV replication using a flow cytometry-based assay that is not biased against cytostasis and reduced cell number. Although we readily reproduced the inhibitory effect of cell confluence on HCV replication, we found no evidence of inhibition by serum starvation, which arrested cell growth as expected. In addition, we observed no inhibitory effect by agents that perturb the cell cycle. Instead, our results suggest that the reduced intracellular pools of nucleosides account for the suppression of HCV expression in confluent cells, possibly through the shutoff of the de novo nucleoside biosynthetic pathway when cells become confluent. Adding exogenous uridine and cytidine to the culture medium restored HCV replication and expression in confluent cells. These results suggest that cell growth arrest is not sufficient for HCV replicon inhibition and reveal a mechanism for HCV RNA inhibition by cell confluence.


1997 ◽  
Vol 322 (2) ◽  
pp. 477-481 ◽  
Author(s):  
John S. HOTHERSALL ◽  
Fernando Q. CUNHA ◽  
Guy H. NEILD ◽  
Alberto A. NOROHNA-DUTRA

Under pathological conditions, the induction of nitric oxide synthase (NOS) in macrophages is responsible for NO production to a cytotoxic concentration. We have investigated changes to, and the role of, intracellular glutathione in NO production by the activated murine macrophage cell line J774. Total glutathione concentrations (reduced, GSH, plus the disulphide, GSSG) were decreased to 45% of the control 48 h after cells were activated with bacterial lipopolysaccharide plus interferon γ. This was accompanied by a decrease in the GSH/GSSG ratio from 12:1 to 2:1. The intracellular decrease was not accounted for by either GSH or GSSG efflux; on the contrary, rapid export of glutathione in control cells was abrogated during activation. The loss of intra- and extracellular glutathione indicates either a decrease in synthesis de novo, or an increase in utilization, rather than competition for available NADPH. All changes in activated cells were prevented by pretreatment with the NOS inhibitor l-N-(1-iminoethyl)ornithine. Basal glutathione levels in J774 cells were manipulated by pretreatment with (1) buthionine sulphoximine (glutathione synthase inhibitor), (2) acivicin (γ-glutamyltranspeptidase inhibitor), (3) bromo-octane (glutathione S-transferase substrate) and (4) diamide/zinc (thiol oxidant and glutathione reductase inhibitor). All treatments significantly decreased the output of NO following activation. The degree of inhibition was dependent on (i) duration of treatment prior to activation, (ii) rate of depletion or subsequent recovery and (iii) thiol end product. The level of GSH did not significantly affect the production of NO, after induction of NOS. Thus, glutathione redox status appears to plays an important role in NOS induction during macrophage activation.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shuangxi Wang ◽  
Jian Xu ◽  
Ping Song ◽  
Yong Wu ◽  
Junhua Zhang ◽  
...  

Objective: GTP cyclohydrolase 1 (GTPCH1) is the rate-limiting enzyme in de novo synthesis of tetrahydrobiopterin (BH4), an essential cofactor for endothelial nitric oxide synthase (eNOS) dictating at least partly, the balance of nitric oxide (NO) and superoxide (O 2 .− ) produced by this enzyme. The aim of this study is to determine the effects of acute inhibition of GTPCH1 on BH4, eNOS function, and blood pressure. Methods: The biopterin content was detected by HPLC. O 2 .− and NO productions were assayed by using DHE and DAF fluorescence respectively. The vessel relaxation was assayed by organ chamber. The blood pressure in wild-type (WT) or eNOS −/− mice was determined by a carotid catheter method. Results: Exposure of bovine or mouse aortic endothelial cells to GTPCH1 inhibitors (10 mM DAHP or 1 mM NAS) for 24 hours or GTPCH1 siRNA transfection significantly reduced both BH4 and NO levels, but increased O 2 .− levels. This increase was abolished by 10 μM L-sepiapterin (BH4 precursor) or 1 mM L-NAME (non-selective NOS inhibitor). Incubation of isolated WT mice aortas with DAHP or NAS for 24 hours impaired acetylcholine-induced endothelium-dependent relaxation, but not endothelium-independent relaxation. Aortas from GTPCH1 siRNA-injected mice, but not their control-siRNA injected mice, also exhibited impaired endothelium-dependent relaxation. Furthermore, GT-PCH1 siRNA injection in mice reduced BH4 levels in aortas, associated with increased aortic levels of O 2 .− , 3-nitrotyrosine, and adhesion molecules (ICAM1 and VCAM1). In addition, an elevated mean, systolic, and diastolic blood pressure was induced by GTPCH1 siRNA injection in vivo , but not control siRNA (mean blood pressure: 114.28±4.48 vs . 136.81±2.45 mmHg) in WT mice. GTPCH1 siRNA was unable to elicit the similar effects in eNOS −/− mice, including increased oxidative stress (O 2 .− , 3-nitrotyrosine, ICAM1, VCAM1) and blood pressure. Finally, sepiapterin supplementation, which had no effect on high blood pressure in eNOS −/− mice, partially reversed GTPCH1 siRNA-induced elevation of systemic blood pressure in WT mice. Conclusion: GTPCH1 via BH4 maintains normal blood pressure and endothelial function by preserving eNOS-dependent NO biosynthesis. This research has received full or partial funding support from the American Heart Association, AHA South Central Affiliate (Arkansas, New Mexico, Oklahoma & Texas).


Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 144-151 ◽  
Author(s):  
CR Jost ◽  
TW Huizinga ◽  
R de Goede ◽  
JA Fransen ◽  
PA Tetteroo ◽  
...  

Abstract Immunoelectron microscopic studies in human neutrophils showed that FcRIII was present on the plasma membrane, in the Golgi complex, and in many small vesicles (120 to 180 nm). FcRIII was not found in specific or azurophilic granules as shown by immunogold double-labeling experiments, visualizing both FcRIII and either lactoferrin (a marker of specific granules) or myeloperoxidase (a marker for azurophilic granules). Because the occurrence of FcRIII in the Golgi complex suggested that biosynthesis of this receptor occurs in these cells, metabolic labeling experiments were performed. Immunoprecipitation of FcRIII from NP-40 lysates of cells labeled with 35S-methionine showed a diffuse 50- to 70-Kd band corresponding with the band noted after immunoprecipitation of FcRIII from surface iodinated cells. These findings show that de novo synthesis of FcRIII occurs in neutrophils and suggest that at least some of the small vesicles containing FcRIII derive from the Golgi complex and thus are involved in transport of newly synthesized FcRIII to the plasma membrane.


1989 ◽  
Vol 108 (1) ◽  
pp. 43-53 ◽  
Author(s):  
K T Tokuyasu

To study whether the first myofibrils are separate from or firmly bound to the myocytic cell membranes, whole mount preparations of 6-12-somite-stage chick embryonic hearts were examined by fluorescence microscopy after double labeling with antibodies to vinculin (fluorescein-conjugated) and rhodamine-phalloidin, or with antibodies to titin (rhodamine-conjugated) and nitrobenz-oxadiazole-phallacidin. When a small number of myofibrils appeared for the first time at the nine somite stage, most of them were already bound to the cell membranes through zonulae adherentes, fasciae adherentes, or costameres. In the outer of the two myocardial cell layers, in which the myocytes were closely in contact with each other along polygonal boundaries, fasciae adherentes and costameres developed at the boundaries, apparently by conversion of preexisting zonulae adherentes. On the other hand, in the inner cell layer, in which myocytes were more loosely associated with each other, both costameres and fasciae adherentes appeared to develop de novo, the former in association with the inner surface of the myocardial wall and the latter at the intercellular boundaries. The myofibrillar tracks in the inner layer followed long and smooth courses and were as a whole aligned in the circumferential direction of the tubular heart wall from the earliest stage of myofibril formation. Those in the outer layer were arranged in a pattern of two- or three-dimensional networks in the 9-10 somite stage, although many myofibrils were also circumferentially directed. The fact that the majority of the first myofibrils were already bound to the cell membranes in a directed manner suggests that myocytes at the earliest stage of myofibril formation are endowed with spatial information that directs the organization of nascent myofibrils. It is proposed that the myocyte cell membranes perform an essential role in cardiac myofibrillogenesis.


1985 ◽  
Vol 24 (8) ◽  
pp. 444-446 ◽  
Author(s):  
Andrew Unger ◽  
Birger Rhenman ◽  
James K. Fuller ◽  
Elmer S. Lightner

Sign in / Sign up

Export Citation Format

Share Document