This study evaluated the effects of inhaled nitric oxide (iNO) therapy combined
with intravenous (IV) corticosteroids on hemodynamics, selected cytokines, and
kidney messenger RNA toll-like receptor 4 (mRNA TLR4) expression in
ischemia–reperfusion injury animal model. The primary endpoint was the
evaluation of circulatory, respiratory, and renal function over time. We also
investigated the profile of selected cytokines and high-mobility group box 1
(HMGB1) protein, as well as renal mRNA TLR4 activation determined by
quantitative real-time polymerase chain reaction analysis. Pigs (n = 19) under
sevoflurane AnaConDa anesthesia/sedation were randomized and subjected to
abdominal laparotomy and alternatively suprarenal aortic cross-clamping (SRACC)
for 90 min or sham surgery: Group 1 (n = 8) iNO (80 ppm) + IV corticosteroids
(25 mg ×3) started 30 min before SRACC and continued 2 h after SRACC release,
followed with decreased iNO (30 ppm) until the end of observation, Group 2
(n = 8) 90 min SRACC, Group 3 (n = 3)—sham surgery. Renal biopsies were sampled
1 hr before SRACC and at 3 and 20 h after SRACC release. Aortic clamping
increased TLR4 mRNA expression in ischemic kidneys, but significant changes were
recorded only in the control group (P = 0.016).
Treatment with iNO and hydrocortisone reduced TLR4 mRNA expression to
pre-ischemic conditions, and the difference observed in mRNA expression was
significant between control and treatment group after 3 h (P = 0.042). Moreover, animals subjected to treatment with iNO and
hydrocortisone displayed an attenuated systemic inflammatory response and
lowered pulmonary vascular resistance plus increased oxygen delivery. The
results indicated that iNO therapy combined with IV corticosteroids improved
central and systemic hemodynamics, oxygen delivery, and diminished the systemic
inflammatory response and renal mRNA TLR4 expression.