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Hepatocyte growth factor is a pleiotropic cytokine with cardioprotective properties. Its serum concentration is markedly raised in end-stage renal disease. This study assessed the relation of hepatocyte growth factor (HGF) with left ventricular mass and geometry in end-stage renal disease. Serum HGF measurements and echocardiographic studies were performed in 185 patients receiving hemodialysis. Patients with serum HGF above the median (1.85 ng/mL) had more frequent cardiovascular complications. This cytokine was directly related to mean left ventricular wall thickness ( r =0.23, P =0.002) and relative wall thickness ( r =0.25, P =0.0001); a multivariate analysis showed that this relation was independent of other risk factors. Accordingly, the prevalence of left ventricular concentric geometry (either concentric left ventricular hypertrophy or remodeling) was much higher (n=49, 53%) among patients with HGF values above the median that in those with values ≤1.85 ng/mL (n=31, 34%). Furthermore, the risk for left ventricular concentric geometry was higher in patients with HGF values above the median (odds ratio, 2.57; 95% CI, 1.33 to 4.98; P =0.005), and multiple logistic regression analysis confirmed that this association was independent of other risk factors. In patients receiving hemodialysis, elevated serum HGF is associated with concentric left ventricular geometry. This is consistent with reports that link this cytokine to arterial remodeling and survival in patients with end-stage renal disease and suggests that it is part of a counterregulatory response aimed at attenuating cardiovascular damage in this high-risk population.

Central serotonergic regulation could have a role in the course of pituitary-dependent Cushing's disease. We studied the effects of ritanserin and ketanserin, two related selective 5HT2 receptor antagonists, in 11 patients with Cushing's disease. Treatment lasted from 1 month to 1 year (up to 4 years in one patient). Daily doses were 10-15 mg for ritanserin, and 40-80 mg for ketanserin. Since the two drugs share the same mechanism of action and no qualitative or quantitative differences in response to their administration were observed, the results were pooled together. Patients were assessed by clinical and hormonal evaluation. Urinary cortisol and ACTH were considered the parameters of interest. Short-term response: after 1 month, there was a significant decrease of urinary cortisol from 781 (160) to 331 (215) nmol/d (P0.02) while ACTH was 9.8 (1.5) pmol/L baseline and again 8.8 (2.2) pmol/L at 1 month (P = NS). For 9 patients, hormonal parameters were available after 1 week of treatment. In this case, also ACTH levels were significantly decreased (from 9.6 (1.7) to 5.2 (1.3) pmol/L; P0.01) together with urinary cortisol (from 781 (194) to 372 (165) nmol/d; P0.01). Long-term response: in 3 patients, hormonal parameters failed to respond to serotonin receptor antagonists, which were thus discontinued. An improvement was recorded in the remaining 8 patients, that was prolonged in 3, and transient in 5. In 3 of these latter patients, a marked increase of ACTH was observed before treatment discontinuation. Ketanserin was given to 2 patients with Nelson's syndrome, with only transient ACTH decrease in one, and no changes in ACTH response to CRH after 1 month treatment in both cases. An inhibitory effect of ritanserin and ketanserin on ACTH and cortisol production in Cushing's disease appeared to be limited both in terms of duration of response and number of patients with a satisfactory outcome. However, the results may provide a better understanding of serotonergic modulation in Cushing's disease and lead to therapeutic developments.

C-type natriuretic peptide (CNP) possesses well-established cardiovascular properties. Although present in the mammalian kidney, CNP production in human kidney and its modulation in human renal disease remain less defined. We investigated the presence of CNP in normal human kidney and in patients with nephrotic syndrome (NS). We also addressed whether or not a low-protein diet (LPD) alters plasma CNP and urinary CNP excretion in NS. In situ hybridization studies demonstrated CNP mRNA expression in tubular cells and glomeruli of normal human kidneys. CNP immunoreactivity was positive in proximal, distal, and medullary collecting duct tubular cells in both controls and patients with NS. The ratios of plasma CNP and urinary CNP to creatinine were significantly higher in patients with NS compared with controls. Urinary CNP, but not plasma CNP, was significantly lowered in patients with NS after an LPD. Similarly, the ratios of urinary protein to creatinine and urinary albumin to creatinine, but not urinary guanosine 3′,5′-cyclic monophosphate to creatinine, decreased significantly with an LPD. These data confirm and extend previous reports and demonstrate for the first time the presence of CNP in human kidney with NS. We also report increased plasma CNP concentration and urinary CNP excretion in NS patients and a significant reduction of CNP excretion with an LPD. Our findings demonstrate that CNP metabolism is altered in patients with NS and support the hypothesis that activation of renal CNP can be partially offset by an LPD. These results underscore that the beneficial effect of an LPD on protein excretion is paralleled by a substantial reduction in intrarenal CNP release.