Carles Cristòfol

Altered porphyrin excretion and histopathology of greylag geese (Anser anser) exposed to soil contaminated with lead and arsenic in the Guadalquivir Marshes, Southwestern Spain

Greylag geese (Anser anser) in the Guadalquivir Marshes (southwestern Spain) can be exposed to sources of inorganic pollution such as heavy metals and arsenic from mining activities or Pb shot used for hunting. We have sampled 270 fecal excreta in different areas of the marshes in 2001 to 2002 to evaluate the exposure to Pb, Zn, Cu, Mn, and As and to determine its relationship with soil ingestion and with the excretion of porphyrins and biliverdin as biomarkers. These effects and the histopathology of liver, kidney, and pancreas were also studied in 50 geese shot in 2002 to 2004. None of the geese had ingested Pb shot in the gizzard. This contrasts with earlier samplings before the ban of Pb shot for waterfowl hunting in 2001 and the removal of Pb shot in points of the Doñana National Park (Spain) in 1999 to 2000. The highest exposure through direct soil ingestion to Pb and other studied elements was observed in samples from Entremuros, the area of the Doñana Natural Park affected by the Aznalcóllar mine spill in 1998. Birds from Entremuros also more frequently showed mononuclear infiltrates in liver and kidney than birds from the unaffected areas, although other more specific lesions of Pb or Zn poisoning were not observed. The excretion of coproporphyrins, especially of the isomer I, was positively related to the fecal As concentration, and the ratio of coproporphyrin III/I was positively related to fecal Pb concentration. Biliary protoporphyrin IX concentration was also slightly related to hepatic Pb concentration. This study reflects biological effects on terrestrial animals by the mining pollution in Doñana that can be monitored with the simple noninvasive sampling of feces.

Pharmacokinetics of meglumine antimoniate after administration of a multiple dose in dogs experimentally infected with Leishmania infantum

Pharmacokinetics of meglumine antimoniate in dogs with experimentally induced leishmaniosis has been investigated. After infection, dogs received a dose of 75 mg kg-1 of meglumine antimoniate twice daily by subcutaneous injection for 10 days. Blood samples were collected throughout the treatment. No statistical differences were found in the kinetic behaviour of the drug administered as a single dose to healthy dogs and that administered as a multiple dose to infected animals. However, peak plasma concentrations (Cmax) of 30.8 +/- 12.8 micrograms ml-1 found after this dosage regimen were higher than those observed after the single dose administration of 100 mg kg-1 24 h-1. Furthermore, sustained antimony concentrations of 1.14 +/- 0.52 micrograms Sb ml-1 were detected throughout the treatment. No signs of toxicity were found in the animals treated indicating that this regimen would be very appropriate to treat canine leishmaniosis.

Anthelmintic induced congenital malformations in sheep embryos using netobimin

Benzimidazole compounds have teratogenic effects in domestic and experimental animals. In this study, 14 Manchega ewes were treated orally, under controlled conditions, with 20 mg netobimin (a prodrug of a benzimidazole compound) per/kg bodyweight on the 17th day of pregnancy. Congenital malformations and abortions affected 60 per cent of the lambs. The main malformations were skeletal and renal, but vascular malformations were observed for the first time. The abnormalities were investigated using radiological, dissection and vascular injection techniques, and associations among them were recorded. The anomalies are discussed in terms of embryological considerations.

Albendazole sulphoxide enantiomers in pregnant rats' embryo concentrations and developmental toxicity.

Three single oral doses (8.5, 10, and 14 mg/kg) of a racemic formulation of albendazole sulphoxide (ABZSO) were administered to pregnant rats on day 10 of gestation. Mother plasma and embryo concentrations of ABZSO enantiomers and albendazole sulphone (ABZSO(2)) were determined 9 h after administration. The (-)-ABZSO enantiomer showed higher peak concentrations in both maternal plasma and embryo than the (+) enantiomer. An increase in embryo concentrations of ABZSO enantiomers and ABZSO(2) was only observed when dose rose to 14 mg/kg. There was an increase in resorption when the dose increased, but significant differences were only found in the higher dose group when compared with the other groups. The incidence of external and skeletal malformations (mostly of the tail, vertebrae and ribs) rose significantly in the 10 mg/kg group, producing almost 20% and 90% of malformed fetuses, respectively, and gross external and skeletal abnormalities in the thoracic region and limbs were also found.

Sex differences in the disposition of albendazole metabolites in sheep.

Sex differences in the disposition of albendazole metabolites in sheep after oral administration of 20 mg/kg of netobimin have been studied. Some kinetic parameters of both metabolites show statistical differences between sexes; the sulphoxide and sulphone t1/2beta and MRT were lower in male animals than in females. Peak concentrations and AUC of sulphone metabolites were higher in males suggesting a greater oxidation rate compared with females. Urine excretion of albendazole metabolites, sulphoxide, sulphone, and amino sulphone appeared to be greater in female sheep than in males, mainly the sulphoxide metabolite. These differences between sexes can be caused by male sexual hormones, because testosterone and progesterone can induce or inhibit the microsomal Cytochrome P450 metabolism. Plasma protein-binding of albendazole sulphoxide and albendazole sulphone has been studied between male and female sheep, also their binding to sheep albumin and globulins. Both albendazole metabolites readily bind to sheep albumin and globulins. Male animals show a significantly lower binding of albendazole metabolites than females. These differences could be responsible for the non-esterified fatty acids (NEFA) present in the plasma. Males have significantly higher plasma levels of NEFA than females and which may compete with albumin for binding to albendazole metabolites.

Developmental toxicity in rat fetuses exposed to the benzimidazole netobimin

Netobimin (NTB) is a prodrug of albendazole (ABZ) and is used as a broad-spectrum anthelmintic both in human and veterinary medicine. Pregnant Sprague-Dawley rats were treated po with 50, 59.5 and 70.7 mg/kg of NTB on Gestational Day (GD) 10. The results, observed on GD 20, demonstrated that NTB induced a significant increase of resorptions. Moreover, decreased fetal body weight and an increase in skeletal malformations were observed in treated groups. We report the first study in which vascular malformations are described in rats after the administration of a benzimidazole compound. An interesting relationship between intercostal vessel and rib malformations was found.

Determination of indomethacin residues in poultry by high-performance liquid chromatography.

A HPLC method using a C18 column and UV detection (254 nm) is described for the determination of indomethacin residues in chicken tissues (liver, muscle and fat). Drug extraction from tissue homogenate in phosphate buffer (pH 3.5) was performed with dichloromethane. Mobile phase was acetonitrile-acetic acid (0.5% in water) (50:50). Indomethacin detection limit was 20 ng/g for the studied tissues. After administration of an oral dose of indomethacin (2 mg/kg), only three of the eight poultry studied showed drug tissue levels, in those cases the levels were below 50 ng/g.

Analysis by LC/ESI-MS of iophenoxic acid derivatives and evaluation as markers of oral baits to deliver pharmaceuticals to wildlife

Iophenoxic acid and its derivatives (methyl, ethyl, and propyl) are organic chemicals used as markers in baiting campaigns to deliver vaccines, pharmaceuticals, contraceptives or poisons to wildlife. In this study we develop a method of detection of IPA derivatives by LC/ESI-MS (using butyl-IPA as internal standard) obtaining a limit of detection and quantification in wild boar (Sus scrofa) serum of 0.037 microg/ml and 0.123 microg/ml, respectively. The average recovery of IPA derivatives was 88% at levels >0.2 microg/ml, with coefficients of variation <15%. Wild boars in captivity were orally treated with 5 mg/kg b.w. (three adults) or 15 mg/kg b.w (two piglets and three adults) of methyl-, ethyl- and propyl-IPA and the serum levels of these were monitored during 18 months after dosing. Ethyl- and propyl-IPA were detected up to 18 months after a single oral dose in wild boar, especially at 15 mg/kg. Methyl-IPA was detected until 9 months after dosing. Half-lives of methyl-, ethyl- and propyl-IPA were (mean+/-SD) 41+/-5, 183+/-85 and 165+/-45 days, respectively. One control piglet not exposed to IPA, but housed in the same facility than treated animals showed detectable IPA levels in serum. Piglets born from mothers exposed to marked baits also showed detectable IPA levels in serum. The high persistence of Et- and Pr-IPA must be considered in the field trials, because the presence of the product at low levels in one animal may not reflect a real ingestion of the marked bait.

Prolongation of Nerve and Epidural Anesthetic Blockade by Bupivacaine in a Lipid Emulsion

UNLABELLED We assessed the effect of a lipid emulsion of bupivacaine on prolonging peripheral nerve and epidural anesthetic blockade in the rat. The intensity and duration of motor and sensory blockade produced by a single injection of aqueous solution (BPV-as) and lipid emulsion (BPV-em) preparations of 0.5% bupivacaine were evaluated by electrophysiological methods. Both preparations induced complete, reversible motor and sensory blockade after injection. The latency time to the maximal blockade and the duration of anesthetic blockade were more prolonged for BPV-em than for BPV-as. The increase in duration of maximal blockade was 1.4 times for nerve and 1.3 times for epidural anesthesia. Histological evaluation of spinal roots and spinal cord sections did not show any abnormalities or differences between animals injected with BPV-as and those injected with BPV-em. Pharmacokinetic studies showed lower plasma peak concentration and a longer elimination half-life for BPV-em than for BPV-as. Thus, BPV-em prolongs the effects of local anesthetics, allows a similar degree of blockade, and reduces the systems toxic effects of anesthetics compared with BPV-as. IMPLICATIONS We assessed a lipid emulsion containing bupivacaine for peripheral nerve and epidural anesthetic blockade in the rat. The emulsion allowed a complete blockade, while increasing the duration of the anesthetic effect (by 30%-40%), compared with the standard bupivacaine aqueous solution.

Effect of age and gender in the pharmacokinetics of albendazole and albendazole sulphoxide enantiomers in goats

The kinetics of albendazole metabolites and albendazole sulphoxide enantiomers were studied in 2- and 14-month-old female and male goats, after a single oral dose administration (10mg/kg) of an albendazole formulation. Blood samples from the jugular vein were collected at 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, 24, 30, 36, 42, 48 and 54h post-treatment and analyzed using a high performance liquid chromatography method. In all groups the area under the plasma concentration-time curve (AUC) and peak concentration (C(max)) values of (+)-ABZSO were significantly higher than those of (-)-ABZSO. The AUC and C(max) values obtained for (+)-ABZSO and (-)-ABZSO in adult animals were higher compared to the results in young animals, showing significant differences except for (+)-ABZSO in female animals. In young animals, independently of gender, the C(max) appeared earlier compared to adult animals. The mean residence time (MRT) values were shorter in young animals compared to adult animals for all compounds analyzed. No sex-related differences were found for any of the parameters calculated except for the (+)-ABZSO from adult animals.