Patients with sepsis undergo acute alterations in the volume and composition of fluid in the intracellular and extracellular spaces. Natriuretic peptides are vasodilator hormones involved in the regulation of blood pressure and volume homeostasis. To elucidate the functional responses of atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP), those peptides levels were measured in the plasma and lung tissue in septic rats with volume load.
Wister rats were anesthetized with ketamine hydrochloride and were intraperitonealy administered 1 μg/kg of lipopolysaccharide (LPS). Three hrs after the LPS administration, normal saline was intravenously infused at 0, 2, 4, and 6 ml/kg/hr for 3 hrs. The samples of blood and lung tissue were taken, and the concentration of ANP and CNP in those were studied by radioimmunoassay. Statistical analyses were performed by Mann-Whitney U test and Kruskal-Wallis test.
Plasma ANP level 3 hrs after the LPS administration increased significantly to 10 times comparing to that of control. By volume load at 2 and 6 ml/kg/hr, plasma ANP levels increased significantly. Lung ANP level 3 hrs after the LPS administration also increased significantly to 2.5 times comparing to that of control. Plasma CNP levels decreased significantly after the LPS administration. By volume load at 2 and 6 ml/kg/hr, plasma CNP levels decreased significantly. Lung CNP decreased significantly after the LPS administration, and showed no significant change by volume load.
ANP and CNP were strongly influenced by LPS administration. Plasma ANP was increased and plasma CNP was decreased by volume load, whereas lung ANP and CNP did not significantly change by volume load in this septic model..
Plasma ANP and CNP are quickly responsive to volume load in septic state.
S. Takamori, None.