Human biomonitoring of persistent organic pollutants in elderly people from the Canary Islands (Spain): A temporal trend analysis from the PREDIMED and PREDIMED-Plus cohorts.

The population of the Canary Islands has been exposed to high levels of persistent organic pollutants (POPs). Biomonitoring studies are essential to know the temporal trend in residue levels, particularly of substances banned decades ago. The purpose of this study was to analyze the distribution of plasma concentrations of 59 POPs in 175 participants from the PREDIMED-Plus trial (2014-2016), and to compare them with the distribution of these POPs in 343 participants in the PREDIMED trial (2006-2009). All participants had metabolic syndrome. No difference in the distribution of age, gender or BMI was observed between trials. POPs were determined by gas chromatography-mass spectrometry. Density plots -POP Geoffrey Rose curves- were used to represent the full population distribution of each compound. Three out of 59 POPs were detected and quantified in ≥95% of the samples (p,p'-DDE, median = 694.7 ng/g lipid; HCB, median = 57.0 ng/g lipid; and ß-HCH, median = 75.7 ng/g lipid). PCB congeners 138, 153 and 180 were detected in 64.6, 40.0 and 88.0% of the samples. Females showed highest concentrations of organochlorine pesticides and those subjects who lost ˃ 5 kg showed significant higher plasma concentrations of POPs. In a range of 6-14 years, plasma concentrations of POPs decreased 3.3-21.6 fold, being notable the decrease of 28.7-fold observed for HCB among women. Despite this sharp decline, levels of POPs are still higher than those reported in other regions, since one third of the subjects included in the present report had high concentration of more than three pollutants. Continuous biomonitoring studies are required to know the evolution of the levels of residues and to evaluate the effectiveness of environmental policies.

Biomonitoring of 45 inorganic elements measured in plasma from Spanish subjects: A cross-sectional study in Andalusian population.

Heavy metals and other toxic elements are frequently detected in humans. Rare earth elements (REE) have arisen as a novel group of substances considered as emerging pollutants due to its dependence for high tech industry. We designed a study aimed to conduct the biomonitoring a total of 45 inorganic elements in the population of Andalusia (Spain). A total of 419 participants were recruited and their plasma samples analyzed. Concentration of elements, including elements in the ATSDR's priority pollutant list and REE were measured by ICP-MS in the blood plasma of participants. Arsenic, copper, lead, selenium, antimony, strontium, and bismuth were detected in ˃98% of subjects. Median values of arsenic, mercury and lead were 1.49, 1.46, and 5.86 ng/mL, respectively. These concentrations did not exceed reference values published by international agencies. We observed a positive correlation between age and plasma concentrations of arsenic, mercury, antimony and strontium. Sum of elements was lower in the group of subjects younger than 45 years old (P = 0.002). Positive correlations were observed between body mass index (BMI) and plasma concentrations of barium, cerium, osmium, tin, and ytterbium. 7 out of 26 REEs showed a percentage of detection ≥ 90%. Bismuth, yttrium, and cerium were quantified at the highest concentrations (median value = 7.7, 0.19, and 0.16 ng/mL, respectively). We found that plasma levels of 6 REEs were higher among males, and a positive correlation between REEs and age was detected. The present results suggest a potential interaction with the human physiology that deserves additional research. Given the high persistence of these elements in the environment, and the significant technological dependence on them, future studies are needed to elucidate the potential sources of exposure and possible adverse effects on health, especially in the most vulnerable populations.

Ethanol levels in legally autopsied subjects (2016-2017): Update of data and epidemiological implications in relation to violent deaths in Canary Islands (Spain).

The aim of this study was to analyze the prevalence of ethanol in individuals (277) subjected to a mandatory medico-legal autopsy in the Institute of Legal Medicine of Las Palmas (Canary Islands, Spain) during 2016-2017, comparing the results with data published in 2015. Blood and/or vitreous humor samples were analyzed by gas chromatography. 31.8% of the individuals were positive to ethanol. We observed a decrease in the prevalence of ethanol among males (p = 0.002). While the prevalence of ethanol was reduced, the concentration among those positive subjects has increased. 11.9% of the series died in a traffic accident and the percentage of positive to ethanol decreased in relation to 2015 (64.3, 25.0, and 35.3%). The number of suicides remains constant, although the age of the suiciders has been significantly reduced (p = 0.022). The results of this study indicate that ethanol is still heavily involved in non-natural deaths.

Organochlorine Pesticides Exposure and Bladder Cancer: Evaluation from a Gene-Environment Perspective in a Hospital-Based Case-Control Study in the Canary Islands (Spain).

The incidence of bladder cancer has increased significantly since the 1950s. Pesticide exposure has been linked with increasing bladder cancer incidence, although the evidence is inconclusive. However, most epidemiological studies did not evaluate the potential role played by the organochlorine pesticides, the most widely used pesticides in Western countries from the 1940s to the 1970s. Organochlorine pesticides were banned in the late 1970s because of their persistence in the environment and their carcinogenic and mutagenic effects. Organochlorine pesticides were employed in huge amounts in the Spanish archipelago of the Canary Islands; the authors, therefore, evaluated the role played by organochlorine pesticides exposure on bladder cancer. Serum levels of the most prevalent organochlorine pesticides used in the agriculture of these Islands (dichlorodiphenyltrichloroethane [p,p'-DDT], and its metabolites dichlorodiphenyldichloroethylene [p,p'-DDE] and dichlorodiphenyldichloroethane [p,p'-DDD], hexachlorobenzene, hexachlorocyclohexane isomers, aldrin, dieldrin, endrin, heptachlor, cis-chlordane, trans-chlordane, α- and ß-endosulfan, endosulfan sulfate, methoxychlor, and mirex) were measured in 140 bladder cancer cases and 206 controls. GST-M1 and GST-T1 gene polymorphisms were genotyped by polymerase chain reaction (PCR)-based methods. These results showed that serum levels of organochlorine pesticides did not increase bladder cancer risk. On the contrary, total burden of hexachlorocyclohexanes was found to be negatively associated to bladder cancer (odds ratio [OR] = 0.929, 95% confidence interval [CI]: 0.865-0.997; P = .041). This effect disappeared when the distribution of the gluthathione S-transferase polymorphisms was introduced in the statistical model. These results indicate that organochlorine pesticides are not a risk factor for bladder cancer. However, these findings provide additional evidence of gene-environment interactions for organochlorine pesticides and bladder cancer and reinforce the relevance of genes encoding xenobiotic-metabolizing enzymes in bladder cancer.

Impacto de las instalaciones ganaderas sobre la calidad y seguridad del agua subterránea / Impact of the livestock facilities on the quality and safety of ground water

La posibilidad de que las actividades ganaderas supongan una fuente de contaminación para los recursos hídricos ha sido una preocupación desde hace ya mucho tiempo, en particular en términos de contaminación por nutrientes (carga nitrogenada, fosfatos, salinidad, etc…). Pero desde hace varias décadas el incremento exponencial de la ganadería intensiva ha magnificado este problema, ya que ha aumentado el número de animales en reducido espacio y ha diversificado la cantidad de contaminantes potenciales (por ejemplo, antibióticos y otros medicamentos veterinarios). Según los datos disponibles, las prácticas generalmente aceptadas de gestión de residuos ganaderos, aún en las mejores condiciones, no garantizan una protección efectiva de los recursos hídricos. De esta manera se ha demostrado que las fuentes de agua cercanas a las actividades ganaderas resultan frecuentemente contaminadas con nutrientes excesivos (N, P, Cl-), patógenos microbianos, productos farmacéuticos, hormonas, metales pesados, desinfectantes, y otros contaminantes de los clasificados como emergentes. La exposición inadvertida a estos residuos procedentes de las instalaciones ganaderas a través de las aguas de consumo puede tener un impacto real sobre la salud humana y del medio ambiente. Por este motivo este tema constituye un problema de preocupación para las autoridades con responsabilidades en materia de Salud Pública. En esta revisión se identifican los principales riesgos de las operaciones de alimentación de animales confinados (CAFO) sobre la salubridad y calidad de las aguas subterráneas y se detallan cuáles son los efectos documentados sobre la salud humana y medioambiental que dichos residuos tienen (AU)

The possibility that livestock activities represent a source of contamination for water resources has been a concern, particularly in terms of nutrient pollution (nitrogen load, phosphates, salinity, etc...). But for decades, the exponential increase in intensive farming has magnified this problem as increased the number of animals in confined space and has diversified the number of potential contaminants (eg, antibiotics and other veterinary drugs). According to available data, generally accepted practices of livestock waste management, even in the best conditions, do not guarantee effective protection of water resources. Thus it has been proved that the sources of water near the concentrated animal feeding operations (CAFO) are frequently contaminated with excessive nutrients (N, P, Cl-), microbial pathogens, pharmaceuticals, hormones, heavy metals, disinfectant by-products, and other pollutants that are classified as emerging contaminants. Inadvertent exposure to these residues from livestock facilities through drinking water can have a real impact on human health and the environment. Therefore this issue is a matter of concern for the authorities with responsibility for Public Health. In this review the principal risks of CAFO activities on the safety and quality of groundwater are identified and listed what are the documented effects on human and environmental health of such pollutants (AU)

Potential adverse effects of inorganic pollutants on clinical parameters of loggerhead sea turtles (Caretta caretta): results from a nesting colony from Cape Verde, West Africa.

A large number of nesting loggerhead sea turtles (n = 201) were sampled to establish the blood levels of 11 elements (Cu, Mn, Pb, Zn, Cd, Ni, Cr, As, Al, Hg, and Se). Almost all of the samples showed detectable levels of these 11 elements, and Zn and Se exhibited the highest concentrations (median values as high as 6.05 and 2.28 µg/g, respectively). The median concentrations of the most toxic compounds, As, Cd, Pb, and Hg, were relatively low (0.38, 0.24, 0.06, and 0.03 µg/g, respectively). We also determined the haematological and biochemical parameters in a subsample of 50 turtles to evaluate the potential effects of these contaminants on clinical parameters and found several associations. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements and their adverse effects on blood parameters in sea turtles.

Presencia de rodenticidas anticoagulantes en cinco especies de aves rapaces de las Islas Canarias, 2003-2011 / Presence of anticoagulant rodenticide residues in five predatory birds species of the Canary Islands, 2002-2011

Se determinó la presencia de residuos de rodenticidas anticoagulantes por cromatografía de líquidos acoplada a espectrometría de masas de triple cuadrupolo en el hígado de 61 aves rapaces muertas provenientes del Centro de Recuperación de Fauna Silvestre de Tafira (Gran Canaria), pertenecientes a 5 especies de las 11 presentes en el archipiélago canario. Se encontraron residuos en 42 animales (69%) si bien en sólo 1 de ellos se consideró la intoxicación por rodenticidas como causa primaria de muerte, según los datos clínicos, analíticos y de necropsia. De las rapaces estudiadas, fueron las especies Tyto alba y Accipiter nisus las que más frecuentemente presentaron residuos de anticoagulantes (85% y 89% respectivamente). Se detectaron residuos de 5 anticoagulantes, todos ellos de segunda generación, siendo la bromadiolona las más frecuentemente detectada, seguida del brodifacoum y del difenacoum. Un elevado número de las muestras positivas (63%) presentó más de un residuo de anticoagulantes en su hígado, habiéndose encontrado mezclas de hasta 4 productos diferentes. Llamó la atención que la mayoría de los animales que ingresaron en el centro de recuperación por politraumatismo por colisión presentaba residuos de uno o varios anticoagulantes, así como que rapaces que se alimentan principalmente de pájaros también presentaron frecuentemente residuos de estos compuestos. Los resultados de este estudio sugieren que el elevado uso de rodenticidas anticoagulantes en el medio natural implica su incorporación a la cadena trófica, viéndose afectadas especies de fauna silvestre en las que estos productos podrían producir efectos adversos. Esto implica que la aplicación de rodenticidas anticoagulantes en espacios abiertos supone una amenaza para el estado de conservación de la biodiversidad de las Islas Canarias (AU)

Anticoagulant rodenticide (AR) levels were studied in liver of 61 dead raptors of five of the eleven species of the Canary Islands. The animals were delivered to our laboratory from the Centro de Recuperación de Fauna Silvestre de Tafira (Gran Canaria). Anticoagulant residues were detected in 42 (69%) of the studied animals, but only 1 may have died by AR poisoning according to the clinical information, necropsy findings and toxicological analysis. Of the studied raptors Tyto alba and Accipiter nisus were the species with more frequency and higher levels of anticoagulants (85% and 89%). Residues of 5 anticoagulants were detected, all of them of second generation, being the most frequently detected bromadiolone, brodifacoum and difenacoum. A large number of samples (63%) presented more than one residue of anticoagulants in their livers, and we have found as much as 4 different residues in one animal. It was remarkable that most of the animals that had suffered polytraumatism by collision presented residues of anticoagulants, and that species such as the hawk that mainly eat birds frequently presented anticoagulant residues. The results of this study suggest that the high use of anticoagulant rodenticides in the natural environment involves their incorporation into the food chain, and this can affect wildlife species in which these products may cause side effects. This means that the application of anticoagulant rodenticides in open spaces poses a threat to the conservation status of biodiversity in the Canary Islands (AU)

Contaminantes orgánicos persistentes en plasma de tortugas bobas (Caretta caretta) varadas en las Islas Canarias / Plasma leves of persistent organic pollutans in loggerhead sea turtles (caretta caretta) stranded in the Canary Islands

En el presente estudio se ha evaluado el grado de contaminación por contaminantes orgánicos persistentes (COPs) en 193 ejemplares de tortuga boba (Caretta caretta) varadas en las Islas Canarias entre 2007-2011. La cuantificación en plasma de los niveles de pesticidas organoclorados (POCs), bifenilos policlorados (PCBs) e hidrocarburos aromáticos policíclicos (PAHs) se realizó mediante GC-MS. Todas las muestras analizadas presentaron niveles cuantificables de alguno de los COPs incluidos en el estudio. El grupo de COPs que presentó mayores niveles fue el de los PAHs (alcanzando la carga total de PAHs 6,45 ng/ml), siendo el fenantreno el hidrocarburo más frecuentemente detectado y a concentraciones más altas, lo que indica el origen petrogénico de estos contaminantes. La contaminación por PCBs alcanzó niveles menores (3,84 ng/ml), predominando el grupo de los hexaclorobifenilos (PCB-153 y PCB- 138 principalmente). Los niveles de contaminación por POCs fueron también bajos alcanzando valores de 1,67 ng/ml, siendo el principal metabolito del DDT, el p,p´-DDE el compuesto más frecuentemente detectado (89,6%) y a más altas concentraciones (0,68 ng/ml). Fue evidente una asociación inversa entre el tamaño de las tortugas y la carga de PCBs y PAHs. Asimismo existieron niveles más altos de contaminación por COPs en los años 2009 y 2010. Este trabajo evalúa por vez primera la presencia de PAHs en sangre de tortugas varadas y nuestros resultados parecen indicar que esta metodología y esta especie animal pueden ser muy útiles para monitorizar la presencia de contaminación por derivados del petróleo en el medio acuático (AU)

This study assessed the degree of contamination by persistent organic pollutants (POPs) present in 193 specimens of loggerhead turtle (Caretta caretta) stranded in the Canary Islands between 2007-2011. Quantification of plasma levels of organochlorine pesticides (POCs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were performed by GC-MS. All samples tested showed measurable levels of several of the POPs included in the study. PAHs was the group that showed the highest levels (total burden of PAHs = 6.45 ng/ml), being phenanthrene the compound most frequently detected and at higher concentrations, indicating the petrogenic origin of these contaminants. PCBs contamination reached lower levels (3.84 ng/ml), dominating the group of hexachlorobiphenyls (PCB-153 and PCB-138 in particular). The pollution levels were also low in the subgroup of POCs, reaching values of 1.67 ng/ml, and being the main metabolite of DDT, p, p'-DDE the compound most frequently detected (89.6%) and at highest concentrations (0.68 ng/ml). There was a clear inverse association between the size of the turtles and the burden of PCBs and PAHs. There were also higher levels of POPs in 2009 and 2010 than in the other years. This study evaluates for the first time the presence of PAHs in stranded turtles blood and our results suggest that this methodology and this animal species can be very useful for monitoring the presence of petroleum derivatives contamination in the aquatic environment (AU)

Polychlorobiphenyls and organochlorine pesticides in conventional and organic brands of milk: occurrence and dietary intake in the population of the Canary Islands (Spain).

The population of the Spanish archipelago of the Canary Islands has been studied in depth regarding its levels of contamination by organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs). Foodstuffs of animal origin, such as milk, are prominent contributors to the body burden of these contaminants. As this population presents one of the highest milk-intake in Spain and Europe, we evaluated the level of OCs and PCBs in 26 commercially available brands of milk (16 conventional and 10 organic brands) present in the market of these Islands, in order to estimate the relevance of milk as a source of these chemicals for the Canary population. Our findings showed that hexachlorobenzene, trans-chlordane, and PCB153 were present in almost all the samples with independence of the type of milk. For both types of milks, the concentration of OCs was very low, showing organic milks lower levels than conventional ones. As a consequence, the estimated daily intake for OCs was lower than the tolerable daily intake (TDI) established by International Agencies. The levels of PCBs in milk were also found to be very low, but, in this case, the situation was the opposite: there were higher levels of PCBs in organic than in conventional brands of milk. Unexpectedly, levels of dioxin-like PCBs (DL-PCBs) reached values higher than 25 pg WHO-TEQ g(-1) fat in percentile 75 for both types of milk indicating the existence of a number of brands of milk highly contaminated by these toxicants. Consequently, the population who consume the most contaminated milk brands could have estimated daily intakes well above the recommended TDI (2 pg WHO-TEQ kg(-1)b.w.d(-1)) established by European Union Authorities. These results are of concern if we consider the well known adverse health effects exerted by dioxin-like compounds.

Sampling methods for assessing syrphid biodiversity (Diptera: Syrphidae) in tropical forests.

When assessing the species richness of a taxonomic group in a specific area, the choice of sampling method is critical. In this study, the effectiveness of three methods for sampling syrphids (Diptera: Syrphidae) in tropical forests is compared: Malaise trapping, collecting adults with an entomological net, and collecting and rearing immatures. Surveys were made from 2008 to 2011 in six tropical forest sites in Costa Rica. The results revealed significant differences in the composition and richness of syrphid faunas obtained by each method. Collecting immatures was the most successful method based on numbers of species and individuals, whereas Malaise trapping was the least effective. This pattern of sampling effectiveness was independent of syrphid trophic or functional group and annual season. An advantage of collecting immatures over collecting adults is the quality and quantity of associated biological data obtained by the former method. However, complementarity between results of collecting adults and collecting immatures, showed that a combined sampling regime obtained the most complete inventory. Differences between these results and similar studies in more open Mediterranean habitats, suggest that for effective inventory, it is important to consider the effects of environmental characteristics on the catchability of syrphids as much as the costs and benefits of different sampling techniques.

Multigenerational study of the hepatic effects exerted by the consumption of nonylphenol- and 4-octylphenol-contaminated drinking water in Sprague-Dawley rats.

Our multigenerational study evaluates the hepatic effects of the xenoestrogens nonylphenol (NP), and 4-octylphenol (4OP) on male and female rats when they are exposed uninterruptedly, from conception to adult age, to tap water containing 25ppm of NP or 4OP. Our results showed that these compounds did not induce any change in liver/body weight ratio (relative liver weight, RLW). In the morphological analysis we did not find evident signs of cytotoxicity. The most relevant findings were the presence of both an increase in the apoptotic index and in the percentage of binuclear hepatocytes in livers from exposed animals. Additionally, our study revealed the presence of hepatocellular glycogenosis (mainly in 4OP-exposed rats): the type of glycogen accumulated was in aggregates (gamma-glycogen), a non-functional form of glycogen. This study demonstrates that, at levels close to those described in the environment, NP and 4OP are capable of inducing a number of hepatic effects, potentially related with adaptive, and/or metabolic alterations of liver tissue.

Increasing serum levels of non-DDT-derivative organochlorine pesticides in the younger population of the Canary Islands (Spain).

Organochlorine pesticides are a lipophilic class of chemicals that persist in the environment and tend to accumulate in human tissues for years. They came into widespread use in the late 1940s. Because of their capacity to bioaccumulate and biomagnify in food chains and their toxic effects, most of them were banned in industrialized countries, among them Spain, in the late 1970s and 1980s. In 1998 organochlorine pesticides were determined in a representative sample of a Spanish population (around 690 serum samples from people 6 to 75years old from the Canary Islands). Serum levels of lindane aldrin, dieldrin and endrin, were determined. Our results showed that a high percentage of samples presented detectable levels of some of the organochlorines measured, endrin being the most frequently detected (72%) and at highest concentration (mean 136.7ng/g fat). Mean concentrations of the main cyclodiene evaluated, dieldrin, was lower to those found in other Western populations. However, serum levels of lindane were higher than those described in North European populations. Influence of geographical and sociodemographic factors was evaluated. Urban populations showed the highest levels of dieldrin, while non-urban population showed the highest serum values of lindane, aldrin and endrin. Unexpectedly, serum values of lindane, aldrin and dieldrin were higher in younger than in older people. Subjects under 18years showed almost twice as high serum levels of lindane, aldrin and dieldrin than subjects of 65-75years. These results may well suggest that people living in the Canary Islands have been and are currently exposed to non-DDT-organochlorine pesticides. The type and source of exposure could vary between islands and type of habitat. Contaminated food and/or the environment could be related with this situation.

Hepatocellular adenomas associated with anabolic androgenic steroid abuse in bodybuilders: a report of two cases and a review of the literature.

Anabolic androgenic steroids (AAS) are used illicitly at high doses by bodybuilders. The misuse of these drugs is associated with serious adverse effects to the liver, including cellular adenomas and adenocarcinomas. We report two very different cases of adult male bodybuilders who developed hepatocellular adenomas following AAS abuse. The first patient was asymptomatic but had two large liver lesions which were detected by ultrasound studies after routine medical examination. The second patient was admitted to our hospital with acute renal failure and ultrasound (US) studies showed mild hepatomegaly with several very close hyperecogenic nodules in liver, concordant with adenomas at first diagnosis. In both cases the patients have evolved favourably and the tumours have shown a tendency to regress after the withdrawal of AAS. The cases presented here are rare but may well be suggestive of the natural course of AAS induced hepatocellular adenomas. In conclusion, sportsmen taking AAS should be considered as a group at risk of developing hepatic sex hormone related tumours. Consequently, they should be carefully and periodically monitored with US studies. In any case, despite the size of the tumours detected in these two cases, the possibility of spontaneous tumour regression must also be taken in account.

Evaluation of acute and chronic hepatotoxic effects exerted by anabolic-androgenic steroid stanozolol in adult male rats.

Stanozolol (ST) is a 17alpha-alkyl anabolic-androgenic steroid (17alpha-AAS) often misused by athletes and bodybuilders. The use of anabolic-steroids by sportsmen and teenagers has increased dramatically, thus raising the question about their hepatotoxicity, specially those such as ST which are orally administered. Previously, we have reported diverse in vivo effects exerted by this steroid and published the existence of a highly specific ST-binding site in male rat liver microsomes. The existence of this binding site, the reported hepatic effects exerted in humans, and the very limited information about its potential hepatotoxicity led us to treat adult male rats acutely and chronically with ST and study different parameters that could indicate liver damage: serum levels of transaminases, concentration of monooxygenase enzymes in liver, liver membrane lipid peroxidation products, liver histopathology, and cell cycle/ploidy status of liver cells. In our study, no changes in serum transaminases or lipid peroxidation levels were obtained. However, acute stanozolol treatment significantly decreased the levels of cytochrome P450 (Cyt. P450) and cytochrome b5 (Cyt. b5) during the first 48 h of treatment, while subsequently, at 72 and 96 h, these microsomal enzymes underwent a significant increase in their levels. In sharp contrast with this response to acute treatment, the content of these two enzymes during chronic treatment showed an important decrease. Interestingly, acutely and chronically ST-treated livers showed slight to moderate inflammatory or degenerative lesions in centrilobular hepatocytes. Flow cytometric analysis demonstrated that both acute and chronic ST treatment were capable of increasing the percentage of S-phase fraction (%SPF) of liver cells. These findings taken together clearly show that this steroid is capable of altering the liver capacity for metabolizing xenobiotics and indicate that high doses of ST could exert a proliferative effect on liver cells. Such data should be considered in risk evaluations for this compound.

Estrogen antagonism on T3 and growth hormone control of the liver microsomal low-affinity glucocorticoid binding site (LAGS).

Male rat liver microsomes contain a low-affinity glucocorticoid binding site (LAGS) capable of binding all natural glucocorticoids and progesterone with a Kd from 20 to 100 nM. The LAGS level is under endocrine control by T3, glucocorticoids and GH. These hormones act synergistically at physiological concentrations to increase the LAGS level. Since female rats show a LAGS level that is much lower than the males (0.15 vs 23 pmol/mg protein, respectively), here we investigated whether estradiol could decrease the LAGS in the male rat. Orchiectomized (OX) male rats showed a higher LAGS level than intact rats. This effect was reversed by implanting a Sylastic capsule containing testosterone. When the OX rats were implanted for 20 days with estrogen capsules that provided an estradiol level in serum of 40 pg/ml, their LAGS level decreased from 23 to 0.2 pmol/mg protein. This effect was not observed in intact male rats and can be partially reversed by testosterone implants into OX rats. Both hypophysectomized male rats and hypothyroid-orchiectomized male rats showed very low levels of LAGS. Administration of physiological doses of GH and/or T3 to these rats greatly increased their LAGS level (from 0.3 to 15 and 16 pmol/mg protein, respectively). Implantation of estrogen capsules to these rats two weeks prior to starting treatment completely inhibited the increase in the LAGS level in response to T3, and significantly decreased the response to hGH, and to a combination of hGH and T3. These results suggest that physiological estradiol levels can antagonize the LAGS induction by T3 and hGH in the male rat, and could be responsible for the low level of LAGS in the female rat. Moreover, estrogen capsules also inhibited the increase in the body and hepatic weights observed after hGH treatment, which suggests a powerful inhibitory effect of low estradiol levels on the male rat liver functions under regulation by T3 and/or GH.

Identification of a specific binding site for the anabolic steroid stanozolol in male rat liver microsomes.

Male rat liver microsomes contain a [3H]dexamethasone binding site, capable of binding glucocorticoids and progesterone. We have shown previously that the 17 alpha-alkylated androgen, stanozolol, can inhibit the [3H]dexamethasone binding to microsomes through a negative allosteric mechanism, which gives rise to the possibility of its interaction with a different binding site. In this study, the existence of a single-saturating binding site, capable of binding the radioactive steroid with a maximum number of the specific binding site of 49 +/- 2 pmol/mg of protein and a Kd of 37 +/- 1.3 nM was demonstrated by using [3H]stanozolol. In competition experiments, only stanozolol and danazol were able to compete with [3H]stanozolol for its binding to microsomes, among more than 60 steroids and other compounds tested. The binding of [3H]stanozolol was depressed after protease treatment of the microsomes, or after the administration of cycloheximide to adult male rats for 24 hr, which suggest its proteic nature. The [3H]stanozolol binding site was detected in many tissues of the rat, with the highest concentrations being found in the liver. It was detected from birth, increasing afterward in concentration and reaching a peak at 2 to 3 months of age. This is the first experimental verification of the existence in liver microsomes of a specific binding site for some 17 alpha-alkylate androgens, such as stanozolol and danazol, different from the androgen receptor or the [3H]dexamethasone binding site.

[3H]dexamethasone binding activity in liver microsomes is modulated differently by 17 alpha-alkylated androgens and testosterone in vivo.

Rat liver microsomes contain a single class of steroid binding sites, capable of binding various glucocorticoids and progesterone. In a previous article, we have described the in vitro interaction of several androgens with this binding site. Unlike natural androgens, the 17 alpha-alkyl derivatives stanozolol and danazol were capable of interacting with this binding site through a negative allosteric pattern. Now, the effects these steroids exert on the microsomal [3H]dexamethasone binding site have been studied in vivo. The administration of a single dose of stanozolol to rats provoked a significant reduction in the microsomal [3H]dexamethasone binding capacity. This effect was maximal two hr after stanozolol administration and persisted for six hr. The restoration of the [3H]dexamethasone binding level after stanozolol administration was dependent on protein synthesis, since it was blocked by the concomitant administration of cycloheximide. None of the other androgens tested (danazol, methyltestosterone, fluoxymesterone, and testosterone propionate) was capable of provoking a similar effect when administered 2 or 24 hr prior to sacrifice. In rats treated for seven days with a daily dose of diverse androgens and sacrificed 24 hr after the last treatment, none of the 17 alpha-alkyl androgens assayed provoked significant changes in the microsomal [3H]dexamethasone binding level, although stanozolol, danazol, and methyltestosterone provoked a significant increase in glucocorticoid receptor concentration. In contrast, the administration of testosterone propionate provoked a 50% reduction in the [3H]dexamethasone binding level without causing changes in the glucocorticoid receptor concentration. These results provide new evidence on the existence of different effects on the liver of 17 alpha-alkyl androgens, compared to the effects produced by natural androgens.

Ethinylestradiol interacts with liver microsomes and induces binding sites for steroid hormones in the male rat liver.

The present work focuses on the interaction of 17 alpha-ethinyl estrogen derivatives with the [3H]dexamethasone ([3H]DEX) binding site from male rat liver microsomes and the induction of this site by the in vivo administration of natural and synthetic estrogens. [3H]DEX binds to a single-saturating binding site (Kd = 100 nM; maximal binding = 13 pmol/mg of protein) in the liver microsomes. In competition experiments, ethinylestradiol (EE2) and mestranol were able to inhibit [3H]DEX binding to microsomes, whereas natural estrogens, tamoxifen or estrogen sulfates were ineffective. Saturation analysis performed by incubating [3H]EE2 with liver microsomes revealed the existence of a low-affinity (Kd = 280 +/- 30 nM) and high capacity (maximal binding = 16 +/- 2 pmol/mg of protein) binding site. Saturation, competition and dissociation experiments suggest that [3H]DEX and [3H]EE2 interact with the same microsomal entity. Synthetic and natural estrogens increased the hepatic expression of the [3H]DEX binding site in immature, hypothyroid and hypophysectomized male rats. This induction required at least 2 days of treatment, and could only be achieved by pharmacological doses of estrogens.(ABSTRACT TRUNCATED AT 250 WORDS)

Histopathological study of Clara cells in lungs from linoleylanilide intoxicated mice.

A histopathological study was made of Clara cells in lungs from mice intoxicated by sc injections of linoleylanilide dissolved in olive oil (20% w/v) at doses of 1,000, 2,500 or 4,000 mg/kg administered at 500 mg/kg on 2, 5 or 8 occasions, respectively. Cells were evaluated for biotransformation capacity. Morphological alterations included degeneration processes in the Clara cells that correlated with the doses administered. The observed lesions were very similar to those caused by xenobiotics with pneumotoxic capacity due to their biotransformation to electrophilic intermediates. The changes observed in Clara cells under our experimental conditions may reflect the activity of reactive catabolites from oleoanilides.

Composition and nutritive value of pejibaye (Bactris gasipaes) in animal feeds.

Nutritive assessment of pejibaye (Bactris gasipaes) meals included proximal composition of the lipid and nitrogenous fractions. Caloric values obtained as true metabolizable energy (TME) indicate that the pejibaye has a higher content of energy than corn and that it is not necessary to separate the seeds from the fruits in animal feeds; the level of indispensable aminoacids is considerably low, especially methionine, which is lower than in corn; thin layer chromatography shows that most of the free fatty acids are present in a ratio of 2:1 in unsaturated to saturated acids. The predominant fatty acids in whole pejibaye meal are oleic and palmitic acids with adequate levels of linoleic acid. Saturated fatty acids are predominant in the seed, with a very high content of lauric and myristic acids.