Effect of nephrotic syndrome on homocysteine metabolism.
Summary of "Effect of nephrotic syndrome on homocysteine metabolism."
Proteinuria and hyperhomocysteinaemia are independently associated with increased risk of atherosclerosis and cardiovascular disease. The available data on plasma homocysteine (Hcy) level in patients with nephrotic syndrome (NS) are contradictory with increased, decreased and unchanged values reported by different investigators. The majority of Hcy in the plasma is bound to albumin whose urinary losses and diminished plasma concentration are the defining features of NS. The present study was designed to explore the effect of NS on plasma concentration and urinary excretion of Hcy and hepatic expression of methylenetetrahydrofolate reductase (MTHFR) and cystathionine-β-synthase (CBS), the key enzymes in re-methylation and trans-sulphuration of Hcy, respectively.
Sprague-Dawley rats were rendered nephrotic by IP injection of puromycin aminonucleoside. Urine and plasma were used for measurement of Hcy, and the liver was processed for assessment of MTHFR and CBS protein expression.
Compared with the controls, nephrotic rats showed heavy proteinuria, hypoalbuminaemia, hypercholesterolaemia, normal plasma creatinine and creatinine clearance, reduced plasma Hcy, increased urinary Hcy, and downregulation of CBS but not MTHFR expression. Plasma Hcy correlated directly with plasma albumin and inversely with urinary protein excretion. The urinary Hcy excretion correlated directly with urine protein excretion.
NS results in significant reduction in plasma total Hcy concentration which is due to the reduction in albumin-bound Hcy as opposed to the free Hcy fraction. This is coupled with increased urinary excretion of albumin-bound Hcy. In addition, NS results in down-regulation of CBS which can curtail conversion of Hcy to cysteine and reduce production of H(2)S which is an important endogenous signalling molecule.
Division of Nephrology and Hypertension, University of California, Irvine, CA, USA.
This article was published in the following journal.
Medical and Biotech [MESH] Definitions
A condition characterized by severe PROTEINURIA, greater than 3.5 g/day in an average adult. The substantial loss of protein in the urine results in complications such as HYPOPROTEINEMIA; generalized EDEMA; HYPERTENSION; and HYPERLIPIDEMIAS. Diseases associated with nephrotic syndrome generally cause chronic kidney dysfunction.
An enzyme that catalyzes the demethylation of L-homocysteine to L-METHIONINE.
Renal syndrome in human immunodeficiency virus-infected patients characterized by nephrotic syndrome, severe proteinuria, focal and segmental glomerulosclerosis with distinctive tubular and interstitial changes, enlarged kidneys, and peculiar tubuloreticular structures. The syndrome is distinct from heroin-associated nephropathy as well as other forms of kidney disease seen in HIV-infected patients.
An enzyme that catalyzes the formation of methionine by transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine. It requires a cobamide coenzyme. The enzyme can act on mono- or triglutamate derivatives. EC 184.108.40.206.
Pathological processes of the KIDNEY without inflammatory or neoplastic components. Nephrosis may be a primary disorder or secondary complication of other diseases. It is characterized by the NEPHROTIC SYNDROME indicating the presence of PROTEINURIA and HYPOALBUMINEMIA with accompanying EDEMA.
Coexistence of nephrotic syndrome and neoplasm is rarely observed in children. We report the diagnostic and therapeutic problems of a 16-year-old female with nephrotic syndrome, ovarian tumor, and inc...
Nephrotic syndrome is basically a set of signs or symptoms that may point to kidney problems, a condition when large amounts of protein leak out into the urine. In children protein excretion greater t...
The introduction of corticosteroids more than 50 years ago dramatically improved the prognosis of children with nephrotic syndrome. Corticosteroids remain the standard initial treatment for children w...
Background: Lecitin cholesterol acyltransferase (LCAT) deficiency comprises a group of rare disorders related to HDL metabolism. These disorders are characterized by ophthalmologic, hematologic, and r...
A 28-year-old women is presented who was evaluated for a new-onset postpartum nephrotic syndrome with normal renal function. Histological diagnosis was AA amyloidosis but no underlying disease has bee...
We want to test the hypothesises that patients with nephrotic syndrome have a higher excretion of AQP2 in the urine,that they have a higher concentration of AVP,and a lower C-H2O.Everythin...
We aim to investigate (1) the effects of combined pentoxifylline and corticosteroids, compared to that of corticosteroids, on patients with primary nephrotic syndrome; and (2) the effects...
OBJECTIVES: I. Determine the effect of atorvastatin on the plasma levels of lipids, Lp(a), and apoproteins for treating hyperlipidemia in children with nephrotic syndrome in whom p...
Exploring the efficacy and safety of Tacrolimus on refractory nephrotic syndrome ; Acquiring the experience of Tacrolimus on the treatment of refractory nephrotic syndrome in Chinese patie...
Parallel group double blind randomised in patients with first episode corticosteroid sensitive nephrotic syndrome comparing time to relapse and adverse effects associated with a longer tap...