Nitric oxide (NO) electrochemical sensors - Electrochemical Sensors, Biosensors and Their Biomedical Applications - page 15

FIGURE 1.6 Abdominal X-ray showing the apparatus consisting of two nitric oxide sensors, a
4-channel pH catheter, and a Tefl on nasogastric tube. (Reprinted with permission from the American
Gastroenterological Association [82].)

a micromanipulator. The results of this work are shown in Fig. 1.7. The fi gure shows
the force (upper traces) and NO concentration (lower traces) in an endothelium intact
( E) segment of the rat superior mesenteric artery and the same segment after mechan-

ical endothelial cell removal ( E). As can be seen from the traces, if endothelial cells

are present the artery is capable of relaxation due to the endothelial cells releasing NO
in response to acetylcholine but if the endothelial cells are removed the artery is insen-
sitive to acetylcholine injection but relaxes upon the introduction of the NO releas-
ing molecule SNAP. In a subsequent publication, Simonsen's group again monitored
artery relaxation and NO concentration in the rat superior mesenteric artery to monitor
its hyporeactivity to various endotoxins [121]. In this study an ISONOP30 electrode
(WPI) was inserted into the lumen of the artery and the NO concentration, as well as
artery relaxation, was measured as a function of endotoxin introduction to determine
what effects lipopolysaccharide had on the artery function. The results nicely showed
that lipopolysaccharide resulted in induction of iNOS and SOD associated with endo-
toxin and NO concentration increased only in response to L-arginine. Simonsen's