Sex ratio and female sexual status of the coconut pest, Oryctes monoceros (Coleoptera: Dynastidae), differ in feeding galleries and pheromone-baited traps.

Oryctes monoceros is a serious coconut pest, causing up to 40% damage in tropical Africa. Synthetic aggregation pheromone, ethyl 4-methyloctanoate, has been used to lure adults to traps. Traps with pheromone plus decaying palm material captured a high proportion of males. This raises the question whether individuals, which damage palms are receptive to the pheromone. We studied the sex ratio of the insects feeding on coconuts and those attracted to pheromone traps. Sixty two percent of adults from feeding galleries on living coconut palms were females. Pheromone with rotting palm material lured 43% females. To investigate the reasons for this difference, we compared the reproductive system of females lured to the odour traps or feeding in coconut galleries, or present in old rotting stems. Ninety six percent of the females trapped by pheromone had mated, and were sexually mature. In the galleries on living palms, 46% of females were immature, and 24% had not mated. In old rotting stems where eggs are laid and larvae develop, a mixture of 52% mated and 48% virgin females was found. Therefore, the pheromone together with the odour of rotting coconut stems signals a reproduction site to beetles, particularly mature females. In practice, the pheromone-baited traps will help in reducing the dissemination of gravid females, but will not affect directly the numbers of immature ones attacking palms. Our results show that when using pheromones for monitoring or controlling insects, the physiological status of the insects may have unexpected effects on the outcome.

[Toxicological study of emissions resulting from a diesel and a gazoline engine using an organotypic culture of lung slice]. / Etude toxicologique des gaz d'échappement issus de moteurs diesel et essence sur une culture organotypique de tissu pulmonaire.

INTRODUCTION: Many studies were carried out in vivo and/or in vitro for better understanding toxic effects of exhausts or particles emitted by Diesel vehicles. Few studies were interested in Gazoline engines when progress of metrology made it possible to highlight the presence of small particles with a strong capacity of penetration within pulmonary tissue. The aim of this study is to compare the toxic impact of the emissions of Diesel and Gasoline engines of recent technology. MATERIALS AND METHODS: Biological material was constituted by an organotypic rat lung precision slice. It was exposed to a continuous flow exhausts thanks to a preparation and dilutions system of these emissions placed on the line of exhaust. A measurement of the biological markers involved in the process of the lung tissue reaction to the air-contaminants was carried out. RESULTS: With Diesel exhausts, the results showed a stability of the rate of ATP and an increase in enzymatic activities of the antioxydant system (GPx and catalase). Gazoline emissions, as for them, were responsible for a cytotoxic attack of the pulmonary tissue defined by a reduction in the rate of ATP as well as a deterioration of the system of detoxication with reduction in the antioxydant enzymatic activities. CONCLUSION: These results show that toxicological profiles obtained with this system of exposure depends on the engine technology used, highlighting thus the specific response of the model in relation with the type of atmospheres which it is exposed.

Impact of after-treatment devices and biofuels on diesel exhausts genotoxicity in A549 cells exposed at air-liquid interface.

Using an air-liquid interface (ALI) device in dynamic conditions, we evaluated the efficiency of fuel after-treatment strategies (diesel oxidation catalysis, DOC, and diesel particulate filter, DPF, devices) and the impact of 7% and 30% rapeseed methyl esters (RME) blending on oxidative stress and genotoxicity induced in A549 lung cells after 3h exposure to whole Diesel exhausts. Oxidative stress was studied using assays of ROS production, glutathione level, catalase and superoxide-dismutase (SOD) activities. No oxidative stress and no clear differences on cytotoxicity patterns between biodiesel and standard Diesel exhausts were found. A weak but significant genotoxicity (8-oxodGuo adducts) and, for standard Diesel only, a DNA damage response (DDR) as evidenced by ƔH2AX foci, remained after DOC+DPF flowing. All together, these data could contribute to the improvement of the after treatment strategies and to health risk assessment of current diesel exhausts.

Expression and subcellular distribution of phosphoenolpyruvate carboxykinase in primary cultures of rabbit kidney proximal tubule cells: comparative study with renal and hepatic PEPCK in vivo.

The behaviour of the phosphoenolpyruvate carboxykinase (PEPCK) in rabbit proximal tubule cells in primary culture was investigated and compared with renal and hepatic PEPCK in vivo. The enzyme activity decreased rapidly in rabbit proximal tubule cells developed in hormonally defined medium supplemented with glucose and insulin. In this condition, the cytosolic form disappears with time. Without glucose and insulin, the subcellular location of PEPCK is similar to the location observed in proximal tubule freshly isolated and in renal cortex, with approx. 50% of mitochondrial form and approx. 50% of cytosolic form. However, the levels of mRNA that encode the cytosolic PEPCK are not detectable in cell cultures, whatever the medium composition. Treatment with dibutyryl cAMP caused a 14-fold induction of PEPCK mRNA in 6 h. This result indicates that the transcription of cytosolic PEPCK can be induced in cell cultures. Lactate or pyruvate additions did not modify the levels of PEPCK mRNA whereas specific activity increased rapidly, suggesting an activation of an inactive form in cell cultures. Moreover, lactate induced increased specific activity of the sole mitochondrial form while pyruvate induced increased specific activities of both mitochondrial and cytosolic form. Thus, subcellular location of PEPCK in rabbit proximal tubule cells appears to be modulated by the available substrate in culture medium. This observation parallels the changes observed in vivo since a modification of subcellular location of this enzyme was seen between fed and fasted rabbit, when subcellular distribution remains similar between fed and starved rats. Moreover, in the fasted liver of rabbit, a decrease of the mitochondrial PEPCK specific activity is seen concomitant with an increase in cytosolic PEPCK activity. These results point out the relative contributions of the cytosolic and mitochondrial PEPCK to rabbit gluconeogenesis.

Comparative mutagenicity and genotoxicity of particles and aerosols emitted by the combustion of standard vs. rapeseed methyl ester supplemented bio-diesel fuels: impact of after treatment devices: oxidation catalyst and particulate filter.

Diesel exhausts are partly responsible for the deleterious effects on human health associated with urban pollution, including cardiovascular diseases, asthma, COPD, and possibly lung cancer. Particulate fraction has been incriminated and thus largely investigated for its genotoxic properties, based on exposure conditions that are, however, not relevant for human risk assessment. In this paper, original and more realistic protocols were used to investigate the hazards induced by exhausts emitted by the combustion of standard (DF0) vs. bio-diesel fuels (DF7 and DF30) and to assess the impact of exhaust treatment devices (DOC and DPF). Mutagenicity and genotoxicity were evaluated for (1) resuspended particles ("off line" exposure that takes into account the bioavailability of adsorbed chemicals) and for (2) the whole aerosols (particles+gas phase components) under continuous flow exposure ("on line" exposure). Native particles displayed mutagenic properties associated with nitroaromatic profiles (YG1041), whereas PAHs did not seem to be involved. After DOC treatment, the mutagenicity of particles was fully abolished. In contrast, the level of particle deposition was low under continuous flow exposure, and the observed mutagenicity in TA98 and TA102 was thus attributable to the gas phase. A bactericidal effect was also observed in TA102 after DOC treatment, and a weak but significant mutagenicity persisted after DPF treatment for bio-diesel fuels. No formation of bulky DNA-adducts was observed on A549 cells exposed to diesel exhaust, even in very drastic conditions (organic extracts corresponding to 500 µg equivalent particule/mL, 48 h exposure). Taken together, these data indicate that the exhausts issued from the bio-diesel fuels supplemented with rapseed methyl ester (RME), and generated by current diesel engines equipped with after treatment devices are less mutagenic than older ones. The residual mutagenicity is linked to the gas phase and could be due to pro-oxydants, mainly for RME-supplemented fuels.

Preparative free flow electrophoresis for the isolation of two populations of proximal cells from the rabbit kidney.

High voltage free flow electrophoresis is a carrier-free method used for analytical and preparative cell separation, based on charge surface properties of cells. Two cell populations from the proximal tubule of the rabbit kidney were isolated by free flow electrophoresis from a suspension of pure proximal cells. This single-cell suspension was obtained through an original method by the combination of a Ca-binder action and gentle mechanical treatment associated with several shifting steps, on a pure suspension of isolated proximal tubules. Before the electrophoretic separation, the proximal cell origin was confirmed by enzymatic marker measurements, and the metabolic capacity was assessed by the cell respiratory activity. The isolated cells were very poor in distal tubule marker enzymes and were enriched in proximal tubule marker enzymes. Respiratory measurement showed a high cell metabolic capacity. After the electrophoretic separation, the origin of the cell populations was assessed by measuring specific marker enzymes. The cells in the slow-moving electrophoresis fractions had a high gamma-glutamyl transpeptidase activity and a low glucose-6-phosphatase activity. The fast moving cells showed a high glucose-6-phosphatase content and a poor gamma-glutamyl transpeptidase activity. Cells isolated by free flow electrophoresis were shown to possess long microvilli. This new methodology, allowed for the first time, the separation of a fast-moving cell population originating from the convoluted portion of the proximal tubule and a slow-moving cell population originating from the straight part of the proximal tubule of the rabbit kidney.

Angiotensin I-converting enzyme in isolated human glomeruli.

Angiotensin I-converting enzyme (ACE) activity was measured with hippurylhistidylleucine as a substrate in isolated human glomeruli. The mean level was 2.2 +/- 0.47 mIU/mg glomerular protein. S9780, a newly designed competitive inhibitor of ACE, inhibited this activity by 85% at 0.3 microM. [3H]S9780 specifically bound to isolated human glomeruli. The Kd value and the number of sites were 23 nM and 83 fmol/mg, respectively. The prodrug, S9490, and Captopril were less potent than S9780 in displacing [3H]S9780 from its binding sites. Angiotensin I had no effect. Binding of [3H]S9780 was inhibited after preincubation of the glomeruli with a specific polyclonal anti-human ACE antibody. These results demonstrate that ACE is present in human adult glomeruli.

The genetics of phenotypic plasticity. IX. Genetic architecture, temperature, and sex differences in Drosophila melanogaster.

We examined the genetic architecture of plasticity of thorax and wing length in response to temperature in Drosophila melanogaster. Reaction norms as a function of growth temperature were analyzed in 20 isofemale lines in a natural population collected from Grande Ferrade near Bordeaux (southern France) in two different years. We found evidence for a complex genetic architecture underlying the reaction norms and differences between males and females. Reaction norms were negative quadratics. Genetic correlations were moderately high between traits within environments. Among characteristic values, the magnitudes of genetic correlations varied among traits and sexes. We hypothesized that genetic correlations among environments would decrease as temperatures became more different. This expectation was upheld for only one trait, female thorax length. For males for both traits, the correlations were large for both very similar and very different temperatures. These correlations may constrain the evolution of the shape of the reaction norms. Whether the extent of independence implies specific regulatory genes or only a specific allelic regulation of trait genes can not be decided from our results.

Seasonally varying diet quality and the quantitative genetics of development time and body size in birch feeding insects.

Genetic variance-covariance structures (G), describing genetic constraints on microevolutionary changes of populations, have a central role in the current theories of life-history evolution. However, the evolution of Gs in natural environments has been poorly documented. Resource quality and quantity for many animals and plants vary seasonally, which may shape genetic architectures of their life histories. In the mountain birch-insect herbivore community, leaf quality of birch for insect herbivores declines profoundly during both leaf growth and senescence, but remains stable during midsummer. Using six sawfly species specialized on the mountain birch foliage, we tested the ways in which the seasonal variation in foliage quality of birch is related to the genetic architectures of larval development time and body size. In the species consuming mature birch leaves of stable quality, that is, without diet-imposed time constraints for development time, long development led to high body mass. This was revealed by the strongly positive phenotypic and genetic correlations between the traits. In the species consuming growing or senescing leaves, on the other hand, the rapidly deteriorating leaf quality prevented the larvae from gaining high body mass after long development. In these species, the phenotypic and genetic correlations between development time and final mass were negative or zero. In the early-summer species with strong selection for rapid development, genetic variation in development time was low. These results show that the intuitively obvious positive genetic relationship between development time and final body mass is a probable outcome only when the constraints for long development are relaxed. Our study provides the first example of a modification in guild-wide patterns in the genetic architectures brought about by seasonal variation in resource quality.

Acrolein toxicity: comparative in vitro study with lung slices and pneumocytes type II cell line from rats.

Toxicological effects of acrolein have been studied in precision-cut rat lung slices and in L2 cells, a rat pneumocyte II cell line. These two models were cultured for 24 h with or without acrolein (0-100 microM in L2 cells; 0-200 microM in lung slices). Treatment with this pneumotoxicant produced a concentration dependent decrease in intracellular ATP levels. Acrolein concentrations higher than 50 microM induced ATP decrease in slices, while this decrease occurred from 10 microM acrolein in L2 cells. Detoxification marker evaluations showed that mostly the glutathione pathway was altered after acrolein treatment in both models. Intracellular glutathione (GSH) levels were drastically increased with an acrolein concentration of 10 microM. This increase was concomitant with glutathione-S-transferase (GST) and glutathione reductase (GRED) activities in L2 cells. After this strong increase, these enzymatic activities as well as GSH levels were quickly decreased. In precision-cut rat lung slices, the induction of the glutathione pathway was less clear-cut. A bell-shaped dose response curve was observed with a maximum for 5 microM acrolein for GST and GRED activities. These differences between acrolein toxic ranges could be explained by the presence of an active detoxification pathway in slices compared to its relative lack in L2 cells.

Role of solid-phase microextraction in the identification of highly volatile pheromones of two Rhinoceros beetles Scapanes australis and Strategus aloeus (Coleoptera, Scarabaeidae, Dynastinae).

Solid-phase microextraction (SPME) samplings from live insects or natural secretion allowed one to identify the aggregation pheromones of the pest beetles Scapanes australis and Strategus aloeus by efficient and rapid isolation of their highly volatile (72 < M(r) < 116) components. S. australis male pheromone was identified as a 84:12:4 (w/w) mixture of 2-butanol [67:33 (R)-(-):(S)-(+) ratio], 3-hydroxy-2-butanone and 2,3-butanediol [43:17:40 (R,R)-(-):(S,S)-(+):meso ratio], and S. aloeus pheromone as a 95.5:4.0:0.5 (w/w) mixture of 2-butanone, 3-pentanone and sec.-butyl acetate by GC-MS using conventional and chiral capillary columns. This is the first report of Scarabaeidae pheromones based on such small and common molecules.

Rabbit kidney proximal tubule cells in primary culture: Evaluation of the impact of expressed phenotype on cellular toxic response.

A primary culture of rabbit kidney proximal tubule cells has been developed from highly purified and calibrated fragments of proximal tubules. Cells are grown without serum in various media. Minimum medium (MM) was composed of glucose-free Dulbecco's modified Eagle's medium plus Ham's F12 (1:1) fortified with sodium selenite plus hydrocortisone plus transferrin. The five types of culture medium used for this study were MM plus 15 mm-glucose with or without insulin (media Ins(+) G1 15 mm; Ins(-) G1 15 mm), MM plus 2.5 mm-glucose, and MM with or without insulin (Ins(+) G1(-); Ins(-) G1(-)). Cellular phenotype is characterized by the assessment of (a) the specific activities of eight enzymatic markers, and (b) cellular functions such as DNA and protein synthesis, and methylglucose transport. This study emphasizes the importance of the effect of the composition of the culture medium on the quality of the phenotype expressed by proximal tubule cells in primary culture. In addition, a study involving the well-known nephrotoxic agent gentamicin has demonstrated the impact of the expressed phenotype on the onset and expression of the specific toxicity pattern: the best gentamicin-toxicity pattern is seen in a medium deprived of insulin and glucose.

Some milestones in in vitro organ Toxicity Assessment. The Kidney as a Case Study.

The expression of target organ toxicity ranges from subtle abnormalities of cellular organelles to permanent loss of organ function. The selective targeting of chemicals for discrete regions and cell types of a given organ is frequently due (besides some pharmacodynamic mechanisms) to the fact that target cells may express unique biochemical or functional characteristics predisposing them to chemically induced injury. In vitro models commonly used in target organ toxicity tests include perfused organ preparations, isolated tissue preparations, single-cell suspensions and tissue culture systems. Although these systems have proved their usefulness for acute toxicity tests, there is still a great need for in vitro models to be used for chronic toxicity tests. Among the systems listed above, the single-cell culture technique may be adapted to long-term study requirements. The example of kidney proximal tubules is taken to illustrate the necessity for extensive characterization of the actual capacities of the models in term of phenotypic profiling, energy status, drug detoxication activities, specific transport systems and organ-specific differentiated functions. LLC-PK1, LLC-RK1, NRK and OK cell lines are compared with primary cultures of rat, rabbit and human proximal tubule cells. The importance of the cell culture environment on the cell phenotypic profile, and its subsequent response pattern to toxicant exposure, are described using gentamicin and platinum derivatives as examples. In terms of experimental strategy, choice of cell type, choice of species of origin, choice of doses, choice of duration, continuous or discontinuous exposure, and whether to study the recovery phase, are crucial issues for designing models mimicking more closely the in vivo situation. The identification of relevant endpoints, allowing discrimination between general cell toxicity and specific organ toxicity, has not been sufficiently explored in vitro. Scientifically based endpoints referring to the background studies conducted by biochemists or physiologists should be selected and included in experimental designs dealing with organ toxicology in vitro. Conceptually, relevant specific target-organ toxicity could be investigated by the use of multiple cell types and by analysis of the difference in concentration between the cytotoxic concentration threshold and the specific endpoint alteration threshold.

Characterization of Precision-cut Rat Lung Slices in a Biphasic Gas/Liquid Exposure System: Effect of O(2).

Influence of oxygen on lung cell differentiation has been studied in precision-cut rat lung slice cultures. Rat lung slices were positioned on rolling inserts placed into vials with opened caps to allow free access to the gaseous phase. This system was placed into a continuous-flow rotating chamber with controlled pO(2), pCO(2) and hygrometry. Slices were cultured in a serum-free medium up to 3 days under an atmosphere of 21 or 70% oxygen. Cellular antioxidant markers demonstrated an oxygen concentration-dependent response. Slices cultured with 70% oxygen exhibited the highest specific activity of catalase, NADPH cytochrome c reductase and gamma-glutamyl transpeptidase (GGT) as well as the highest levels of intracellular glutathione after 48 or 72 hours of incubation. Moreover, hyperoxic exposure altered the expression of lung manganese-containing superoxide dismutase mRNA. Hyperoxia had little or no effect on intracellular ATP levels, which remained high in lung slices compared with freshly isolated tissue. The study of the pulmonary specific functions allowed to confirm maintenance of the in vitro cellular differentiation of lung slices incubated with 21% oxygen: (i) polyamine transport is preserved and exhibited kinetic properties similar to those observed in lung in vivo; (ii) ATP levels remained constant throughout the time course of incubation. This in vitro model proves to be a useful tool to study mechanisms involved after oxygen exposure and will probably be useful for the study of other environmental gaseous contaminants. Further developments in this method are under development.

Morphological and biochemical characterization of primary culture of rabbit proximal kidney tubule cells grown on collagen-IV coated Millicell-CM.

The aim of this study was to better characterize rabbit proximal kidney tubule cells cultured on collagen IV-coated porous inserts, as compared to the same cells seeded in standard plastic wells. Total protein contents in confluent monolayers on permeable membranes were about twofold higher than those measured in confluent cultures in plastic wells. Microscopy examinations suggested that such a difference was probably due to a higher cell density and to an impressive development of the apical brush-border membrane. Moreover, measurement of unidirectional transport of p-aminohippuric acid and tetraethylammonium bromide confirmed the high polarization level of cultures on porous inserts. Results of methyl(alpha-D-[U-14C]glyco)pyranoside uptake suggested that cell phenotype was probably influenced by culture conditions. Analysis of different markers as a function of time in culture showed decreases of alkaline phosphatase (AP), gamma-glutamyltranspeptidase (GGT), and Na(+)-K(+)-ATPase activities as well as increases in LDH, ATP, and glutathione levels, similar to those formerly reported for cells cultured in standard plastic plates. However, comparative data from 6-d-old monolayers have shown that AP, GGT, Na(+)-K(+)-ATPase, glutathione reductase (GRED), and selenium-dependent glutathione peroxidase (Se-GPX) activities were 2.8-, 2.6-, 1.6-, 1.2-, and 2.1-fold, respectively, better preserved on precoated permeable membranes. On the other hand, this paper reports for the first time in the literature that GRED and SE-GPX, two phase II detoxification enzymes, were well maintained in cultures of rabbit proximal kidney tubule cells. Our results show that culturing rabbit proximal kidney tubule cells on collagen IV-coated porous membranes was accompanied by an improvement of both morphological and biochemical properties of the cells.

Pharmacokinetics and renal accumulation of three iodinated contrast agents. A comparative study of Telebrix, Hexabrix and Omnipaque in the rabbit.

Male and female New Zealand rabbits were given a single bolus injection of 5 ml/kg of Telebrix, Hexabrix or Omnipaque intravenously. Animals were sacrificed 2, 8 and 24 h after the injection. One group of animals received a continuous i.v. infusion of contrast medium at a constant rate of 2.5 ml/kg/h for 4 h. Animals from this group were killed 30 min after the end of the infusion. Product clearance from plasma was studied in the animals given the i.v. bolus of contrast material and sacrified at 24 h postinjection. Plasma and tissue concentrations of contrast material were determined by high-performance liquid chromatography. Plasma elimination half-lives were identical in males and females and for all three products (approximately 45 min). The same held true for the volume of distribution which comprised between 20 and 26% of body weight. At 2 h postinjection, renal cortical concentrations of contrast medium were 8 to 10 times higher than plasma concentrations. For all three contrast agents, concentrations found in the renal cortex were higher than those in the medulla or the papilla at all observation times. As compared with the evolution of plasma concentrations over time, renal accumulation of the products was found to be persistent. The ionic or non-ionic nature of the tested products and their hydrophilic properties seem to play an essential role in the renal accumulation pattern.

The cellular toxicity of two antitumoural agents derived from platinum, cisplatinum versus oxaliplatinum, on cultures of tubular proximal cells.

There is a large scope for the use for cisplatin and its derivatives in the treatment of human malignancies. Nephrotoxicity is their most important use-limiting factor. The aim of this study has been to compare cisplatin (CDDP) and oxaliplatin (1-OHP), a new derivative, on cultures of tubular proximal cells. Three cells models were used: primary culture of rabbit kidney, proximal tubular cells (RPTC) and established opossum kidney (OK) and pig kidney (LLC-PK1) epithelial cell lines. Results indicate that in these three culture systems, the cytotoxicity-ranking of the two molecules were in agreement with their in vivo nephrotoxicity (CDDP > 1-OHP), but were less cytotoxic for OK and LLC-PK1 cells than for RPTC. Functional and biochemical evaluations in RPTC indicate that toxic effects of platinum derivates are exerted on DNA, protein synthesis and glucose uptake. 1-OHP effect on DNA synthesis seems to be more effective, but induced a more progressive cytotoxicity. Alteration of glutathione-dependent detoxication activities may reflect the occurrence of a lipid peroxidation process. The present study showed that 1) RPTC are more suitable that LLC-PK1 or OK cells for investigating the nephrotoxicity of platinum derivatives; 2) 1-OHP seems to have a more powerful pharmacological effect than CDDP. The toxic effect ratio seems to promise greater safety with 1-OHP than with CDDP.

Haematotoxicity of doxorubicin and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) and of their association in rats.

Doxorubicin is an anthracycline widely used in the treatment of leukaemias, lymphomas and solid tumors. Doxorubicin cannot pass into the cerebrospinal fluid. Nitrosoureas are known to be lipophilic and to be able to penetrate the blood-brain barrier. CCNU is a nitrosourea used to treat Hodgkin's disease, brain tumors and other solid tumors. The authors have previously reported on the nephrotoxicity and hepatotoxicity of these drugs; the present paper reports their findings on haematotoxicity in female Wistar rats. In one group 40 rats received 10 mg/kg doxorubicin. In a second group 40 rats received 20 mg/kg CCNU, and a further 40 rats received 50 mg/kg CCNU. In a third group 60 rats received the association doxorubicin 10 mg/kg plus CCNU 20 mg/kg. Blood counts were performed on days 4, 8, 15, 21 and 28 after treatment. Leucopenia and severe thrombocytopenia were noted after doxorubicin administration. A biphasic decrease in the leucocyte count was observed after CCNU treatment. More severe alterations were observed when doxorubicin and CCNU were combined. Very few data on haematological abnormalities following treatment of human patients have been published. Similarities can be seen between the haematological side-effects noted in rats and those occurring in humans treated with these cytotoxic drugs. Female Wistar rats seemed to be a good model to evaluate the haematological tolerance of anthracycline, nitrosoureas or of their association. If multiple courses of these drugs have to be administered, the evolution of haematological alterations must be known: the decrease phase of blood cells is followed by a rebound phase. The drug should be avoided during this phase of granulocyte activation.

High affinity binding sites for Perindopril a new inhibitor of angiotensin-I-converting enzyme (ACE) in the rabbit kidney: possible evidence for localization of ACE in endothelial structures and in glomerular mesangium.

The tissue distribution of Perindopril, a new potent inhibitor of the angiotensin-converting enzyme (ACE), was studied after in vivo intravenous injection into rabbits of tracer amounts of the tritiated drug either alone (no modification of the renin angiotensin system) or along with a pharmacologic dose of 10 mg/kg unlabelled Perindopril. Lung and kidneys were the most densely labelled tissues. Kidney distribution of tritiated Perindopril was studied either by histo-autoradiography or by measurement of radioactivity in the homogenates of dissected kidney zones. A close parallelism was found between the distribution patterns of ACE and radioactivity throughout the kidney. Tritiated-Perindopril binding was inhibited by concurrent treatment of the animals with the unlabelled drug or pretreatment with Captopril. Autoradiographic study of kidney slices after the administration of tracer amounts of Perindopril showed an intense labelling of the glomerular mesangium and of endothelial structures of blood vessels, and a lack of labelling of tubular epithelial cells. The possible occurrence of two pools of "ACE-like" activity in the kidney is discussed, namely i) one pool which is labelled by tritiated Perindopril, located in glomerular mesangium and endothelial structures which may be involved in the pharmacological action of ACE inhibitors; and ii) a second pool located in the proximal-tubule cell brush-border, remaining unlabelled by Perindopril, for which the high amount of neutral endopeptidase present at this site may be responsible.

Regenerating tubular cell process in rat kidney: influence of gentamicin treatment.

Aminoglycoside antibiotics are accumulated in lysosomes of proximal tubule cells in the renal cortex. After gentamicin administration in Wistar rats at the daily doses of 10 or 50 mg/kg during 4, 7 or 14 days, we have observed an increase of the number density of lysosomes from proximal cells, an increase of the mean lysosomal perimeter, and a rise of the lysosomal overloading with myeloid bodies. Analysis of lysosomal size distribution (as perimeters) during these treatments shows two kinds of lysosomes, small and large, the latter being characteristic of necrotized cells. A theoretical calculation between control lysosomal distribution of perimeters and the distribution of lysosome perimeters observed after treatment reveals an excess of the small type of lysosome during regenerative time (i.e. 8 days after the end of a 7-day treatment with 10 or 50 mg/kg of gentamicin). This calculation shows a regenerative process during the treatment with the high dose. This morphometric study of the proximal tubule cell during gentamicin treatment reveals the early events of cell damage before any biochemical changes in kidney cortex or blood creatinine level can be observed.