Evidence for 4-hydroxyalkenals in rat renal cortex peroxidized by N2-methyl-9-hydroxyellipticinium acetate or Celiptium.

The antitumor drug celiptium is an ellipticine derivative whose nephrotoxic pathogenesis implicates a lipid peroxidation process. It has been shown that hydrophobic lipid deposits overload the proximal tubular cells. Histochemistry with Holczinger's technique has demonstrated that these deposits are free fatty acids. In this study, the fatty acid analysis of phospholipids and neutral lipids was performed in rat renal cortex 4 and 8 days following a single i.v. dose of 20 mg/kg celiptium and showed: (1) a loss of polyunsaturated fatty acids within total phospholipids and a loss of phosphatidylethanolamine with a preferential decrease of arachidonic (20:4) and docosahexaenoic (22:6) acids; (2) an increase of free fatty acid levels with an increase in oleic (18:1) and linoleic (18:2) acids; (3) an increase of thiobarbituric acid-reactive substances or aldehydes. The analysis of these aldehydes showed significant amounts of 4-hydroxyalkenals, mainly the presence of 4-hydroxynonenal on day 4 and of a hydroxyaldehyde with a chromatographic behavior very similar to 4-HNE on day 8. We conclude that celiptium induced a preferential decrease of phosphatidylethanolamine linked to the formation of unsaturated free fatty acids and of 4-hydroxyalkenals. The toxic side-effects of these breakdown products produced in the proximal tubular cell are discussed in light of the lipid peroxidation process involved in the renal toxicity of celiptium.

Celiptium-induced nephrotoxicity and lipid peroxidation in rat renal cortex.

The antitumor drug celiptium, or N2-methyl-9-hydroxyellipticinium (NMHE), is an ellipticine derivative used in the treatment of breast cancer. Celiptium-induced dose-dependent renal toxicity in rats is characterized by tubular necrosis, tubulo-interstitial lesions and lipid overload in proximal tubular cells. Since biooxidative activation of celiptium occurs in kidney via highly electrophilic intermediates, we studied the effects of celiptium on rat renal cortex lipids in the context of lipid peroxidation damage. Female Wistar rats were injected with a single i.v. dose of 20 mg/kg celiptium and were killed on day 2, 4 or 8. Histochemical analysis of kidney sections detected Oil Red O (ORO)-positive deposits, whereas the same sections studied using Holczinger's copper rubeanic acid method showed free fatty acid (FFA) granules in renal tubular cells of celiptium-treated rats. Electron microscopy revealed large fatty droplets in proximal tubular cells. As creatinine clearance decreased on days 4 and 8, celiptium induced a significant increase in renal cortex FFA levels (6-fold increase over pretreatment values on day 8), whereas total glycerides increased 1.5 times. A 15% decrease in total phospholipids (PL) and a 50% decline in the mass of phosphatidylethanolamine (PE) were detected by lipid phosphorus assay. A 1.2-fold decrease in the unsaturation index of total PL was noted, with a significant decline in arachidonic acid (20:4). A 15% decrease in arachidonic content was observed in the fatty acid composition of PE. Analysis of the fatty acid composition of neutral lipids showed changes only in the FFA class. A great proportion of oleic (18:1) and linoleic (18:2) acids was found. Iodometric titration and thiobarbituric acid (TBA) reactivity detected respectively significant amounts of lipid hydroperoxides and TBA-reactive material in renal cortex lipid extracts on days 2, 4 and 8. The lipid-peroxidation process appeared to be involved in the pathogenesis of celiptium nephrotoxicity.

[Can piperacillin modify the experimental nephrotoxicity of gentamicin?]. / La pipéracilline est-elle capable de modifier la néphrotoxicité expérimentale de la gentamicine?

A synergistic effect of antibacterial activity has been demonstrated with piperacillin combined with an aminoglycoside. Four groups of 30 female Wistar rats were injected daily for 14 days with either gentamicin 50 mg/kg, or piperacillin 1,000 mg/kg, or both drugs combined; the control group received sodium chloride in solution. In all groups, creatinine clearance, lysosomal structural latency and renal cortex enzyme activities (alanine-aminopeptidase, N-acetyl beta D-glucosaminidase, sphingomyelinase, cathepsin B) were measured on days 2, 4, 7, 10 and 14 of treatment. Renal cortex concentrations of gentamicin were measured in the group that received gentamicin alone and in the group treated with both piperacillin and gentamicin. The renal functional changes usually induced by aminoglycosides were observed. Piperacillin administered alone reduced creatinine clearance and alanine-aminopeptidase activity. The piperacillin-gentamicin combination proved unable to prevent the fall in creatinine clearance; it also reduced the alanine-aminopeptidase, sphingomyelinase and cathepsin B activities, but the reduction was less pronounced than that induced by gentamicin alone.

Renal toxicity of the antitumor drug N2-methyl-9-hydroxyellipticinium acetate in the Wistar rat.

Celiptium (N2-methyl-9-hydroxy-ellipticinium) is an antitumoral agent used to treat bone metastases from breast carcinomas. This new drug appeared to be of great interest because of the absence of hepato- or myelotoxicity. Three different investigators recently mentioned cases of celiptium-induced renal failure. We therefore undertook a study of renal function and morphology in female Wistar rats. Two single i.v. doses (10 or 20 mg/kg) were administered and animals were sacrificed 4, 8, 15, 28 and 60 days after injection. One group of rats received multiple doses, 5 mg/kg/week for 8 weeks. No mortality was observed. With the 10 mg/kg single dose creatinine clearance (Ccr) and urinary enzymes did not change, and tubular lesions were rare. With the 20 mg/kg single dose CCr decreased on day 4 and returned to normal on day 28. Urinary enzyme excretion (AAP, NAG, gamma GT) increased. Renal lesions were diffuse with tubular necrosis, luminal dilation and later (day 28) interstitial cellular infiltration. These lesions persisted on day 60 and appeared to be irreversible. Ultrastructural studies showed numerous large fat droplets in proximal tubular cells. Glycerol concentrations in renal cortex homogenates were increased while phospholipids are slightly decreased. With 5 mg/kg every week (multiple doses) Ccr decreased and tubular lesions similar to the observed with the 20 mg/kg single dose were seen. Thus celiptium induced dose-dependent nephrotoxicity in rats with prolonged tubular alterations.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical exploration of azoospermia: interest of the seminal transferrin assay.

Seminal transferrin is considered a good index of Sertoli cell function. In this study, including 19 control subjects, four vasectomized subjects and 65 non-vasectomized subjects with azoospermia, transferrin was measured concomitantly with other classical biochemical seminal markers such as L-carnitine, fructose and zinc. This parameter should provide additional information for differentiation between obstructive and non-obstructive azoospermia. A threshold value of 85 micrograms/ejaculate for transferrin was defined in the control and the vasectomized groups. The 65 subjects with azoospermia were divided into five groups according to L-carnitine and transferrin threshold values; the nature of azoospermia (obstructive or non-obstructive) was considered in each group. In the biological investigation of sterility, the measurement of transferrin provided information as to the aetiology of azoospermia. However, the determination of L-carnitine and fructose remains important in the localization of any obstruction.

[Pharmacokinetics of cyclosporin A in patients with nephrotic syndrome]. / Pharmacocinétique de la ciclosporine A chez les patients atteints de syndrome néphrotique.

The pharmacokinetics of Cy A have been studied in patients with N.S.. Eight patients (7 M, 1 F) received a single 12.5 mg/kg oral dose and a single 4 mg/kg intravenous dose. Plasma was separated from red blood cells at 22 degrees C, at least 2 hr after drawing. Cy A plasma levels were determined by reverse HPLC. The comparison of our pharmacokinetic parameters for the oral route with those from reference patients showed significant differences for T1/2 Ka and Tmax which were decreased in N.S. For the I.V. route we found a decrease in total plasma clearance (CLTP). Absolute bioavailability (18%) was also diminished. Moreover total cholesterol and B apolipoprotein were increased in our nephrotic population. Cy A is highly bound to lipoprotein and we found a significant negative correlation between CLTP of Cy A and either B apolipoprotein or total cholesterol. We conclude that the increase of lipoprotein in N.S. is probably responsible of the modifications in pharmacokinetics of Cy A. Nevertheless Cy A dosage can be not modified in N.S. when oral route is used and divided by a factor two for the I.V. route.