I. Tsuneyoshi et al., NITRIC-OXIDE AS A MEDIATOR OF REDUCED ARTERIAL RESPONSIVENESS IN SEPTIC PATIENTS, Critical care medicine, 24(6), 1996, pp. 1083-1086
Objective: To investigate the functional status of arteries in patient
s with septic shock, each of whom suffered from severe hypotension. De
sign: Experimental, comparative study. Setting: Laboratory in a univer
sity hospital. Subjects: Mesenteric artery resected from omentum was o
btained from patients (n = 3) with or without (n = 4) sepsis. Interven
tions: To study the effect of modification of the nitric oxide system
in human arteries during sepsis, changes in norepinephrine evoked isom
etric tension in mesenteric arterial rings were measured. Measurements
and Main Results: Mesenteric arteries were isolated from omentum rese
cted from three patients with septic shock and from four patients with
no inflammatory conditions; in each case, during an intestinal anasto
mosis, In arterial rings, after a l-hr equilibration with Krebs soluti
on, changes in isometric tension evoked by norepinephrine were measure
d for 5 mins every 20 mins, The tension initially evoked in rings from
septic patients was lower than in those rings from nonseptic patients
and, unlike the controls, it decreased with a short time course, The
addition of 300 mu mol/L of N-G-nitro-L-arginine methyl ester or 10 mu
mol/L of methylene blue reversed this decrease. Conclusion: These res
ults indicate that in patients with septic shack, the main cause of re
duced sensitivity to presser agents may be a massive generation of nit
ric oxide via the L-arginine pathway.