摘要:

We measured blood pressure, platelet cytosolic calcium concentration ([Ca2+]i) and vasoactive hormones in 20 anuric normotensive patients on chronic hemodialysis (HD) to clarify the role of cytosolic calcium in regulation of blood pressure. All measurements were performed at the end of HD (post-HD) and at the beginning of the next HD (pre-HD). During the HD-HD interval, mean blood pressure increased from 85 ± 4 to 94 ± 4 mm Hg (mean ± SEM, p < 0.05), but the median [Ca2+]i in platelets did not show any significant change (133 ± 5 vs. 136 ± 5 nmol/l). Although all patients were within their ideal body weight at post-HD, platelet [Ca2+]i did not correlate with mean blood pressure. By contrast, platelet [Ca2+]i correlated with mean blood pressure (r = 0.489, p < 0.05) at pre-HD. Moreover, platelet [Ca2+]i at post-HD also correlated with changes in mean blood pressure during the HD-HD interval (r = 0.532, p < 0.05). In addition, there were negative correlations between platelet [Ca2+]i and plasma renin activity both post- and pre-HD (r =-0.652, p < 0.005; r = -0.673, p < 0.005; respectively). These results suggest that cytosolic calcium plays important roles in regulation of renin secretion and in the elevation of blood pressure induced by volume expansion in patients on chroni

ISSN:1660-8151    

DOI:10.1159/000186963

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Forty-four elements (Al, Sb, As, Ba, Be, B, Br, Cd, Ce, Co, Cr, Cs, Cu, Eu, Ga, Au, Hf, In, Ir, Fe, La, Lu, Mn, Hg, Mo, Nd, Ni, Pb, Rb, Sm, Sc, Se, Ag, Sr, Ta, Tb, Tl, Th, Sn, W, U, V, Zn, Zr) have been determined in the dialysate for hemodialysis (HD) and fluids for hemofiltration (HF) and continuous ambulatory peritoneal dialysis (CAPD). Multiple determinations have been performed for each dialysis fluid. Several trace elements (TE) showed remarkably elevated average levels; moreover, different bathes of the same commercial product may present a wide variability in TE concentration. The data point out the pivotal role of dialysis fluids in contributing to TE imbalance in dialysis patients and allow the assessment of the potential element exposure of patients on regular dialytic treatment. Patients on HD treatment would be exposed on a weekly basis to milligrams of Al, B, Ba, Br, Cu, Fe, Ni, Pb, Rb, Sr and Zn; on HF, the highest exposures are due to Al, B, Br, Fe, Pb and Zn; on CAPD to B, Br, Fe and Zn. The weekly exposure for several TE appears to be 50- to 12,000-fold higher than the corresponding values on the amount absorbed via the diet (HD: Au, Ba, Be, Ce, Ga, La, Sc, Ta, Th, V, Zr; HF: Be, Ce, Ta, Th, V, Zr; CAPD: Au, Be, Ce, Ga, V, Zr). Although the actual contamination could be markedly influenced by other factors, such as the chemical form of the element or its ability to bind carriers, our data on TE exposure from dialysis fluids can give an insight for further studies on TE imbalances in dialyzed patients.

ISSN:1660-8151    

DOI:10.1159/000186964

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Glutathione (GSH)-dependent reactions are an important cellular defense against ischemic or oxidative injury, although their role in toxin-induced renal cellular injury is less clear. Because of the known sulfhydryl reactivity of mercury (M), we hypothesized that GSH could modify mercuric chloride (MC)-induced acute renal failure (ARF). Therefore, we evaluated the effects of glutathione monoethyl ester (GE), which produces high intrarenal levels of GSH, on the nephrotoxicity of MC. GE treatment in normal rats did not alter their creatinine clearance (CCr), fractional sodium (CNa/CCr) or lysozyme (CLy/CCr) excretion, but histologically resulted in prominent proximal tubular vacuolization. GE pretreatment in rats with MC-induced ARF resulted in partial preservation of their CCr CNa/CCr and CLy/CCr· Renal histology also demonstrated a reduction in tubular necrosis. M content in the renal cortex 3 following MC was lower in the MC + GE group, but levels were higher in the liver and inner stripe/inner medulla as compared to animals receiving MC alone. No differences were seen in the outer stripe at 3 h or in any of the tissues 24 h following MC injection. Thus, GE moderated MC-induced ARF, likely by providing a large intracellular sulfhydryl pool and thereby reducing M reactivity with endogenous cellular proteins and enzymes

ISSN:1660-8151    

DOI:10.1159/000186965

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The accumulation of extracellular matrix (ECM) is an important feature of most forms of progressive glomerular diseases. In order to examine the relationship between ECM synthesis and glomerulosclerosis, we evaluated fibronectin synthesis by glomeruli with the immunoprecipitation of conditioned media from isolated glomeruli in 5/6 nephrectomized spontaneously hypertensive rats (5/6 N-SHR). There was no difference in blood pressure between 5/6 N-SHR and control SHR throughout the experiment. Two weeks after the nephrectomy, most of the glomeruli were intact and no difference in the synthesis of fibronectin was observed between either groups. Twenty weeks after the nephrectomy, marked glomerulosclerosis associated with an increase in urinary protein was revealed in 5/6 N-SHR but no glomerular lesions in control SHR. The synthesis of fibronectin by isolated glomeruli increased in 5/6 N-SHR compared to control SHR. The administration of enalapril or hydralazine + reserpine + hydrochlorothiazide markedly attenuated the glomerular sclerosis and urinary protein excretion to a comparable degree, although the later therapy reduced blood pressure more effectively. These antihypertensive therapies also suppressed fibronectin synthesis in the 5/6 N-SHR group at week 20. In conclusion, increased synthesis of glomerular fibronectin appeared to contribute to the glomerulosclerosis caused by subtotal nephrectomy and hypertension.

ISSN:1660-8151    

DOI:10.1159/000186966

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Studies were done in partially nephrectomized rats to examine the effect of dietary sodium intake on atrial natriuretic factor (ANF) released by the atria. Experiments were done in four groups of male Wistar rats. Group 1 (n = 10) and 3 (m = 10) rats were sham-operated. Group 2 and 4 were 5/6 nephrectomized. Group 1 and 2 were fed a sodium-supplemented diet. Group 3 and 4 received a sodium-deficient diet. Renal functions were similar between group 2 and 4. Plasma ANF level was raised in group 2 (182 ± 17 pg/ml). Circulating ANF levels in group 1,3 and 4 were 95 ± 5,90 ± 5 and 95 ± 4 pg/ml, respectively. Atrial ANF contents were higher in partially nephrectomized rats after receiving a sodium-supplemented diet. A reduction in atrial ANF contents occurred when fed a sodium-deficient diet. In vitro studies were done to assess the rate of ANF released. ANF secretory rates were highest in group 2 (11 ± 1.5 pg/min/mg). There was no difference between group 1,3 and 4. A positive correlation was found between plasma ANF and ANF released in all groups examined. Thus, plasma ANF levels were a good reflection of ANF secretory rates. A significant correlation existed between plasma ANF and sodium excretion in chronic renal failure rats (r = 0.78; p < 0.01). A dissociation between plasma ANF and water excretion was seen. These results suggest that in chronic renal failure rats, ANF played a role in sodium adapta

ISSN:1660-8151    

DOI:10.1159/000186967

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000186968

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000186969

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000186970

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000186971

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000186972

出版商:S. Karger AG    

年代:1992

数据来源: Karger