Atrial natriuretic peptide attenuates kidney-lung crosstalk in kidney injury

Abstract

Background: Renal ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury after cardiovascular surgery, which in turn deteriorates oxygenation. Atrial natriuretic peptide (ANP) has natriuretic, diuretic, and anti-inflammatory effects. To elucidate whether renal IRI induces inflammation in the kidney and lung and ANP attenuates kidney-lung crosstalk.

Materials and methods: The rats were anesthetized, tracheostomized, mechanically ventilated, and randomized to four groups: saline + IRI (n = 12), ANP + IRI (n = 12), ANP + sham (n = 6), and saline + sham (n = 6). Saline (6 mL/kg/h) or ANP (0.2 μg/kg/min) at the rate of 6 mL/kg/h was started 5 min before clamping, respectively. Renal IRI was induced by clamping the left renal pedicle for 30 min. The hemodynamics, arterial blood gases, and plasma concentrations of creatinine and lactate were measured at baseline and 1, 2, and 3 h after declamping. Lung wet-to-dry ratio was measured. The mRNA expression of tumor necrosis factor (TNF)-α, interleukin (IL) 1β, and IL-6 and histologic localization of TNF-α in the kidney and lung were measured.

Results: Renal IRI induced metabolic acidosis, pulmonary edema, increases in plasma concentrations of creatinine and lactate, and augmentation of the cytokine mRNA expression and histologic localization of TNF-α in the kidney and Renal IRI induced lung. ANP prevented IRI-induced metabolic acidosis, pulmonary edema, increases in creatinine, lactate, and the cytokine mRNA expression, attenuated histologic localization of TNF-α in the kidney and lung, and increased oxygenation.

Conclusions: ANP has renoprotective and anti-inflammatory effects on the kidney and lung in a rat model of renal IRI, suggesting that ANP attenuates kidney-lung crosstalk.

Keywords: Acute kidney injury; Atrial natriuretic peptide; Cytokine; Ischemia–reperfusion; Lung inflammation; Rat.