atrial-natriuretic-factor and Peritonitis

The natriuretic effect of atrial natriuretic peptide (ANP) is blunted in certain clinical disorders such as congestive heart failure and liver cirrhosis, despite the elevated plasma ANP levels. These sodium-retaining states are characterized by increased activity of the renal sympathetic nerves. Recent studies have shown higher levels of circulating and urinary catecholamines in cancer patients. We hypothesized that the increased adrenergic activity may be responsible for ascites formation in patients with peritonitis carcinomatosa (PC). The objective of this study was to determine the renal responses to endogenous ANP in patients with PC. Patients, hospitalized at our institute for PC, were examined using renal clearance studies for 2 h. Non-cancer patients were also examined as control subjects. Statistical analysis was performed using Wilcoxon's rank sum test. The results showed that absolute and fractional sodium excretions were markedly lower in patients with PC (54 +/- 16 microEq/min, means +/- SE, p < 0.0005; 0.55 +/- 0.15%, p < 0.005) than in control patients (166 +/- 14 microEql/min; 1.14 +/- 0.09%, respectively). Plasma ANP concentration was increased in patients with PC (34.7 +/- 8.4 pg/ml, p < 0.001) in comparison with control patients (13.3 +/- 2.0 pg/ml). Plasma and urinary levels of norepinephrine were significantly higher in cancer patients (0.36 +/- 0.10 ng/ml, p < 0.05; 125 +/- 20 ng/dl GF, p < 0.05) than in the controls (0.17 +/- 0.02 ng/ml; 73 +/- 13 ng/dl GF). These results suggest that increased renal sympathetic nerve activity may contribute to the attenuation of the natriuretic effect of ANP in patients with PC.

Topics: Adult; Aged; Atrial Natriuretic Factor; Cachexia; Cyclic GMP; Female; Guanosine; Humans; Kidney; Kidney Function Tests; Male; Middle Aged; Natriuresis; Norepinephrine; Peritoneal Neoplasms; Peritonitis; Sodium

Atrial natriuretic peptide (ANP) was recently reported to ameliorate fibrosis in the heart and experimental renal diseases and vascular thickening after balloon injury. Peritoneal fibrosis is an important complication of long-term peritoneal dialysis, and peritonitis is a factor in its onset. In the present study, we investigated the effects of ANP in a rat peritonitis-induced peritoneal fibrosis model.. As pretreatment, an osmotic pump containing vehicle (saline) or ANP (0.15 or 0.3 μg/min) was inserted through the carotid vein in male Sprague-Dawley rats. ANP or saline was continuously infused using the osmotic pump. Three days after administration of ANP or saline, rats underwent peritoneal scraping in a blind manner and were sacrificed on Day 14. The effects of ANP were evaluated based on peritoneal thickness, immunohistochemistry and real-time polymerase chain reaction. In each experiment, we evaluated messenger RNA (mRNA) expression of the ANP receptor natriuretic peptide receptor A (NPR-A) in the peritoneum after scraping. The effects of ANP were also studied in cultured peritoneal fibroblasts and mesothelial cells.. We observed a significant increase in NPR-A mRNA in the peritoneum. Peritoneal thickness increased with time and peaked on Day 14, but ANP significantly reduced peritoneal thickness. Parameters such as number of macrophages and CD-31-positive vessels and expression of type III collagen/transforming growth factor-β/plasminogen activator inhibitor-1 (PAI-1)/connective tissue growth factor (CTGF) were significantly suppressed by ANP. In cultured peritoneal fibroblasts and mesothelial cells, ANP suppressed angiotensin II-induced upregulation of CTGF and PAI-1.. Our results suggest that ANP is useful in preventing inflammation-induced peritoneal fibrosis.

Topics: Analysis of Variance; Animals; Atrial Natriuretic Factor; Biopsy, Needle; Cells, Cultured; Disease Models, Animal; Fibroblasts; Immunohistochemistry; Infusions, Intravenous; Male; Peritoneal Fibrosis; Peritoneum; Peritonitis; Random Allocation; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptors, Atrial Natriuretic Factor; Reference Values; RNA, Messenger; Sensitivity and Specificity; Statistics, Nonparametric

N-terminal prohormone of atrial natriuretic peptide ((proANP(1-98)) has been extensively analyzed in patients with chronic renal failure. It has been found to be closely related to the renal function and to interdialytic hydration status. The clinical relevance of proANP(1-98) and cystatin C, a novel marker of glomerular filtration, has not been investigated in the subgroup of critically ill septic patients with no history of chronic renal impairment.. We measured plasma level ofproANP(1-98) and cystatin C in 29 critically ill septic patients on admittance to the surgical intensive care unit and correlated it with the occurrence of acute renal failure.. The proANP(1-98) plasma level was significantly higher in the group of patients who developed renal failure (12,722 +/- 12,421 vs. 2,801+/- 2,023 fmol/ml, p < 0.05). Multiple regression analysis shows that proANP(1-98) on the first day in the intensive care unit has a superior predictive value for the occurrence of renal failure to diuresis, calculated creatinine clearance or cystatin C (r = 0.42, p < 0.039). proANP(1-98) is also higher in non-survivors (9,303.8 +/- 11,053 vs. 2,448.5 +/- 1,803 fmol/ml, p < 0.018).. proANP(1-98) is possibly a better predictor of acute renal failure to calculated creatinine clearance or diuresis among critically ill septic patients. Cystatin C was not correlated with occurrence of acute renal failure in this subgroup of patients.

Topics: Acute Kidney Injury; Adolescent; Adult; Aged; Atrial Natriuretic Factor; Biomarkers; Critical Illness; Cystatin C; Cystatins; Female; Humans; Male; Middle Aged; Peptide Fragments; Peritonitis; Predictive Value of Tests; Prospective Studies; Sepsis