Urinary porphyrins as biological indicators of oxidative stress in the kidney: Interaction of mercury and cephaloridine

doi:10.1016/0006-2952(93)90614-3

Biochemical Pharmacology

Volume 46, Issue 12, 14 December 1993, Pages 2235-2241

https://doi.org/10.1016/0006-2952(93)90614-3 Get rights and content

Abstract

Reduced porphyrins (hexahydroporphyrins, porphyrinogens) are readily oxidized in vitro by free radicals which are known to mediate oxidative stress in tissue cells. To determine if increased urinary porphyrin concentrations may reflect oxidative stress to the kidney in vivo, we measured the urinary porphyrin content of rats treated with mercury as methyl mercury hydroxide (MMH) or cephaloridine, both nephrotoxic, oxidative stress-inducing agents. Rats exposed to MMH at 5 ppm in the drinking water for 4 weeks showed a 4-fold increase in 24-hr total urinary porphyrin content and a 1.3-fold increase in urinary malondialdehyde (MDA), an established measure of oxidative stress in vivo. Treatment with cephaloridine alone (10–500 mg/kg, i.p.) produced a dose-related increase in urinary MDA and total porphyrin levels up to 1.6 and 7 times control values, respectively. Injection of MMH-treated rats with cephaloridine (500 mg/kg) caused a synergistic (20-fold) increase in urinary porphyrin levels, but an additive (1.9-fold) increase in the MDA concentration. Studies in vitro demonstrated that cephaloridine stimulated the iron-catalyzed H₂O₂-dependent oxidation of porphyrinogens to porphyrins in the absence of either microsomes or mitochondria. Additionally, porphyrinogens were oxidized to porphyrins in an iron-dependent microsomal lipid peroxidation system. Moreover, porphyrinogens served as an effective antioxidant (EC₅₀ ∼ 1–2 μM) to lipid peroxidation. These results demonstrate that MMH and cephaloridine synergistically, as well as individually, promote increased oxidation of reduced porphyrins in the kidney and that this action may be mechanistically linked to oxidative stress elicited by these chemicals. Increased urinary porphyrin levels may, therefore, represent a sensitive indicator of oxidative stress in the kidney in vivo.

References (36)

J.M.C. Gutteridge et al.
The measurement and mechanism of lipid peroxidation in biological systems
Trends Biochem Sci
(1990)
H.H. Draper et al.
Malondialdehyde determination as index of lipid peroxidation
Methods Enzymol
(1990)
J.J. Hageman et al.
Monitoring of oxidative free radical damage in vivo: Analytical aspects
Chem Biol Interact
(1992)
B.O. Lund et al.
Mercury-induced H₂O₂ production and lipid peroxidation in vitro in rat kidney mitochondria
Biochem Pharmacol
(1991)
B.O. Lund et al.
Studies on Hg(II)-induced H₂O₂ formation and oxidative stress in vivo and in vitro in rat kidney mitochondria
Biochem Pharmacol
(1993)
J.S. Woods et al.
Urinary porphyrin profiles as biomarkers of trace metal exposure and toxicity: Studies on urinary porphyrin excretion patterns during prolonged exposure to methyl mercury
Toxicol Appl Pharmacol
(1991)
S.K. Mukerji et al.
Free radical mechanism of oxidation of uroporphyrinogen in the presence of ferrous iron
Arch Biochem Biophys
(1990)
S.K. Mukerji et al.
Dual mechanism of inhibition of rat liver uroporphyrinogen decarboxylase activity by ferrous iron: Its potential role in the genesis of porphyria cutanea tarda
Gastroenterology
(1984)
J.S. Woods
Attenuation of porphyrinogen oxidation by glutathione in vitro and reversal by porphyrinogenic trace metals
Biochem Biophys Res Commun
(1988)
J.S. Woods et al.
Iron stimulation of free radical-mediated porphyrinogen oxidation by hepatic and renal mitochondria
Biochem Biophys Res Commun
(1989)

B.F. Burnham et al.

Enzymatic syntheses of porphyrins

M.A. Bowers et al.

Investigation of factors influencing urinary porphyrin excretion in rats: Strain, gender, and age

Fundam Appl Toxicol

(1992)

R.S. Goldstein et al.

Biochemical mechanisms of cephalorodine nephrotoxicity

Life Sci

(1988)

R.S. Goldstein et al.

Biochemical mechanisms of cephaloridine nephrotoxicity: Time and concentration dependence of peroxidative injury

Toxicity Appl Pharmacol

(1986)

T.C. Pederson et al.

Aminopyrine demethylase. Kinetic evidence for multiple microsomal activities

Biochem Pharmacol

(1970)

C. Cojocel et al.

Cephaloridine-induced lipid peroxidation initiated by reactive oxygen species as a possible mechanism of cephaloridine nephrotoxicity

Biochim Biophys Acta

(1985)

D.M. Miller et al.

Redox activities of mercury-thiol complexes: Implications for mercury-induced porphyria and toxicity

Chem Biol Interact

(1993)

J.S. Woods et al.

Studies on the etiology of trace metal-induced porphyria: Effects of porphyrinogenic metals on coproporphyrinogen oxidase in rat liver and kidney

Toxicol Appl Pharmacol

(1989)

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The action of some anticonvulsant drugs as the causal agents of attacks of acute porphyria has been widely documented in the literature. However, little attention has been paid to the effect of these drugs on the urinary excretion of porphyrins in non-porphyric subjects. In a sample of 82 epileptic patients treated with phenobarbital (n = 54), phenytoin (n = 64), carbamazepine (n = 33), and valproate (n = 8), the daily doses were expressed according to a drug score that would reflect the capacity of these drugs as enzymatic inducers when administered in polytherapy. A significantly increased urinary excretion of D-glucaric acid (DGA) and porphyrins was found in this group of patients (P<0.001), with coproporphyrin being the major fraction in all cases (>60%). Urinary DGA had a highly significant correlation with the drug score (r = 0.783, P<0.001); however, no significant correlations were found between the urinary porphyrins and DGA (r = 0.005) or the drug score (r = 0.053). Neither was any significant relationship found between the urinary porphyrins and the serum activity of 5′-nucleotidase (r = 0.066) or the presence of a cholestasis objectivized through the presence of the isoform of γ-glutamyltransferase with β-globulins electrophoretic mobility. However, in a group of 10 patients a significant correlation was found between the urinary excretion of porphyrins and β-N-acetylhexosaminidase (r = 0.790, P<0.01). Therefore, it does not appear that the liver enzyme induction, or even a subclinical cholestasis, produced by the antiepileptic drugs administered to these patients may serve to explain the increase in the urinary excretion of porphyrins. A possible renal origin is proposed for the increase of urinary porphyrins in these cases.
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The renal handling of porphyrins is reported to be a sensitive marker for chronic renal failure (CRF) for two reasons: heme is synthesised in proximal tubules and porphyrins are reabsorbed in the renal proximal tubule by apical peptide transporter PEPT 2. Two different models of CRF in female Wistar rats have been used for investigation of renal porphyrin handling: (1) single administration of uranyl nitrate (UN; 0.5 mg/100 g b.wt.) and (2) 5/6 nephrectomy (5/6NX). Renal clearance experiments were performed at weeks 2 and 10 after the onset of CRF. The concentrations of porphyrin intermediates (uroporphyrin I and III, coproporphyrin I and III, heptaporphyrin, and pentaporphyrin) were measured by HPLC with fluorescence detection.
Both after UN and 5/6NX a significant reduction of body weight occurred. The kidney weight was enhanced 2 weeks after UN compared to controls (+31%). After 5/6NX, the weight of the remnant kidney was 44% (2^nd week) and 140% (10^th week) higher compared to one control kidney.
Urine volumes and GFR were significantly reduced at week 2 and 10 after 5/6NX, but at week 10 after UN values were comparable to controls.
Two weeks after UN and 5/6NX the concentrations of heptaporphyrin was moderately decreased in renal tissue whereas after 10 weeks the concentrations of most porphyrins were increased in the kidney. The plasma levels of free porphyrins were only slightly enhanced (week 2). The renal excretion of porphyrins was initially slightly reduced in both models, whereas it increases 10 weeks after UN, but it remained reduced 10 weeks after 5/6NX.
UN induces tubulointerstitial fibrosis including atrophic glomeruli, whereas 5/6NX was characterized by distinct proteinuria, dilated tubules containing hyaline casts. A modulation of porphyrin metabolism in the kidney seems first of all to be responsible for UN effect on renal porphyrin handling. Summing up the 5/6NX results, both reduction in intact renal tissue mass and a modification of enzymes involved in heme biosynthesis by uraemic toxins are responsible for accumulation of porphyrins in renal tissue. After 5/6NX reduced excretion of porphyrins into urine and enhanced porphyrin concentrations in the kidney indicate more a damage of renal porphyrin biosynthesis than changes in their reabsorption.

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Urinary porphyrins as biological indicators of oxidative stress in the kidney: Interaction of mercury and cephaloridine

Abstract

Trends Biochem Sci

Methods Enzymol

Chem Biol Interact

Biochem Pharmacol

Biochem Pharmacol

Toxicol Appl Pharmacol

Arch Biochem Biophys

Gastroenterology

Biochem Biophys Res Commun

Biochem Biophys Res Commun

Fundam Appl Toxicol

Life Sci

Toxicity Appl Pharmacol

Biochem Pharmacol

Biochim Biophys Acta

Chem Biol Interact

Toxicol Appl Pharmacol