In Vivo Real‐Time Measurement of Nitric Oxide in Anesthetized Rat Brain

Barbosa, Rui M.; Lourenço, Cátia F.; Santos, R. M.; Pomerleau, François; Huettl, Peter; Gerhardt, Greg A.; Laranjinha, João

doi:10.1016/s0076-6879(08)01220-2

Cited by 66 publications

(40 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…38 ROS generation in VSMCs cocultured with L-NAME-treated ECs was similar to that in VSMCs cocultured with vehicle-treated ECs, indicating that negative modulatory effects of ECs are probably eNOS-independent. However, because NO has a very short half-life and diffuses only short distances from its site of production, 38,39 we cannot exclude the possibility that NO may be converted to nitrate and nitrite before it takes effect in VSMCs. We also explored the possibility that Cox2-derived PGI 2 and 20-HETE, other important EC-derived mediators, 40,41 may influence redox homeostasis in VSMCs.…”

Section: Discussionmentioning

confidence: 99%

Endothelial Cells Negatively Modulate Reactive Oxygen Species Generation in Vascular Smooth Muscle Cells

Vokurková

et al. 2009

Hypertension

View full text Add to dashboard Cite

Abstract-In intact vessels, endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) act as an integrated system, possibly through reactive oxygen species (ROS). Using a coculture system we tested whether ECs modulate VSMC redox status by regulating activity of NAD(P)H oxidase and antioxidants. VSMC production of O 2 •Ϫ , H 2 O 2 , and NO was assessed using fluoroprobes and amplex-red. NAD(P)H oxidase subunit expression and oxidase activity were determined by Western blotting and chemiluminescence, respectively. Expression of thioredoxin, SOD, growth signaling pathways (PCNA, p21cip1, CDK4, ERK1/2, p38MAPK) was evaluated by immunoblotting. Thioredoxin activity was assessed by the insulin disulfide reduction assay. In cocultured conditions, VSMC ROS production was reduced by Ϸ50% without changes in NAD(P)H oxidase expression/activity versus monoculture (PϽ0.05). This was associated with decreased cell growth (PϽ0.05). Expression of Cu/Zn SOD and thioredoxin was increased in coculture versus monoculture VSMCs (PϽ0.01). Pretreatment of ECs with L-NAME (NOS inhibitor), NS-398 (Cox2 inhibitor), and HET0016 (20-HETE inhibitor) did not influence VSMC ROS formation, whereas CDNB, thioredoxin reductase inhibitor, abolished ROS modulating effects of ECs. These findings indicate that in a coculture system recapitulating intact vessels, ECs negatively regulate ROS production in VSMCs through thioredoxin upregulation. Functionally this is associated with growth inhibition. The modulatory actions of ECs are independent of NOS/NO, Cox2, and HETE and do not involve NAD(P)H oxidase. Our data identify novel mechanisms whereby ECs protect against VSMC oxidative stress, a process that may be important in maintaining vascular integrity.

show abstract

Section: Discussionmentioning

confidence: 99%

Endothelial Cells Negatively Modulate Reactive Oxygen Species Generation in Vascular Smooth Muscle Cells

Vokurková

et al. 2009

Hypertension

View full text Add to dashboard Cite

show abstract

“…Therefore it is plausible that this translates to the results described within, whereby salts from the PBS electrolyte adsorb on the Nafion ® surface after repeated exposure, compromising its integrity over time. Previously, a number of groups have investigated the simultaneous combination of Nafion ® and PPD on carbon fiber electrodes in the expectation of improving sensor performance [6,16,17,39]. Two variations of this polymer combination were investigated and the results are presented in Table 1.…”

Section: Shelf-life Studies-effect Of Repeated Aa Calibrationsmentioning

confidence: 99%

Ascorbic Acid Rejection Characteristics of Modified Platinum Electrodes: A Shelf Life Investigation

Wynne

Finnerty

2015

Chemosensors

View full text Add to dashboard Cite

Ascorbic acid (AA) is the principle interferent present in brain extracellular fluid that can inhibit the ability of electrochemical sensors to selectively detect a particular analyte of interest. Considerable efforts have been made in recent times to develop highly selective membrane coatings to counteract the drawbacks associated with AA interference during in vivo monitoring. The primary objective of the work described within was to investigate the long term effect of storing such selective membranes, i.e., Nafion ® andPoly-o-phenylenediamine (PPD) under different conditions and how exposing them to repeated calibration protocols compromises the membranes ability to reject AA. Four different modified platinum (Pt) electrodes, Pt-PPD, Pt-Nafion ® (5/2), Pt-Nafion ® (1/2)-PPD, and Pt-Nafion ® (2/1)-PPD, stored at 4 °C demonstrated deterioration of the polymers integrity when exposed to repeated calibrations. On the contrary, exposing the same four electrode types to single calibrations confirmed excellent retention of AA rejection characteristics. Pt-PPD electrodes were then exposed to varying storage conditions and calibrated against AA on day 1, day 56 and day 168. Storing the Pt-PPD electrodes at 4 °C/N2 saturated glass container demonstrated retention of AA rejection characteristics after day 168. These results have clearly elucidated the optimum storage conditions for Pt-Nafion ® and Pt-PPD modified electrodes.

show abstract

“…In vivo, NO is available in low concentration and it has a short half-life and high reactivity with other biological molecules. 52 Therefore, it is very challenging to perform the NO real-time measurement in vivo. Tsai and colleague used microelectrodes coated with Nafion to measure perivascular NO at the end of microhemodynamic measurement by removing a coverglass of dorsal skinfold chamber.…”

Section: Gas Transport Measurementmentioning

confidence: 99%

Intravital microscopy in a dorsal skinfold chamber: hemodynamics, tumor angiogenesis and inflammation

Duansak¹,

Chatpun²

2013

Int Jour of Biomed Res

View full text Add to dashboard Cite

In Vivo Real‐Time Measurement of Nitric Oxide in Anesthetized Rat Brain

Cited by 66 publications

References 38 publications

Endothelial Cells Negatively Modulate Reactive Oxygen Species Generation in Vascular Smooth Muscle Cells

Endothelial Cells Negatively Modulate Reactive Oxygen Species Generation in Vascular Smooth Muscle Cells

Ascorbic Acid Rejection Characteristics of Modified Platinum Electrodes: A Shelf Life Investigation

Intravital microscopy in a dorsal skinfold chamber: hemodynamics, tumor angiogenesis and inflammation

Contact Info

Product

Resources

About