Patterned apoptosis has an instructive role for local growth and tissue shape regulation in a fast-growing epithelium.

What regulates organ size and shape remains one fundamental mystery of modern biology. Research in this area has primarily focused on deciphering the regulation in time and space of growth and cell division, while the contribution of cell death has been overall neglected. This includes studies of the Drosophila wing, one of the best-characterized systems for the study of growth and patterning, undergoing massive growth during larval stage and important morphogenetic remodeling during pupal stage. So far, it has been assumed that cell death was relatively neglectable in this tissue both during larval stage and pupal stage, and as a result, the pattern of growth was usually attributed to the distribution of cell division. Here, using systematic mapping and registration combined with quantitative assessment of clone size and disappearance as well as live imaging, we outline a persistent pattern of cell death and clone elimination emerging in the larval wing disc and persisting during pupal wing morphogenesis. Local variation of cell death is associated with local variation of clone size, pointing to an impact of cell death on local growth that is not fully compensated by proliferation. Using morphometric analyses of adult wing shape and genetic perturbations, we provide evidence that patterned death locally and globally affects adult wing shape and size. This study describes a roadmap for precise assessment of the contribution of cell death to tissue shape and outlines an important instructive role of cell death in modulating quantitatively local growth and morphogenesis of a fast-growing tissue.

Microtubule disassembly by caspases is an important rate-limiting step of cell extrusion.

The expulsion of dying epithelial cells requires well-orchestrated remodelling steps to maintain tissue sealing. This process, named cell extrusion, has been mostly analysed through the study of actomyosin regulation. Yet, the mechanistic relationship between caspase activation and cell extrusion is still poorly understood. Using the Drosophila pupal notum, a single layer epithelium where extrusions are caspase-dependent, we showed that the initiation of cell extrusion and apical constriction are surprisingly not associated with the modulation of actomyosin concentration and dynamics. Instead, cell apical constriction is initiated by the disassembly of a medio-apical mesh of microtubules which is driven by effector caspases. Importantly, the depletion of microtubules is sufficient to bypass the requirement of caspases for cell extrusion, while microtubule stabilisation strongly impairs cell extrusion. This study shows that microtubules disassembly by caspases is a key rate-limiting step of extrusion, and outlines a more general function of microtubules in epithelial cell shape stabilisation.

A Review of the Developmental Processes and Selective Pressures Shaping Aperture Pattern in Angiosperms.

Pollen grains of flowering plants display a fascinating diversity of forms. The observed diversity is determined by the developmental mechanisms involved in the establishment of pollen morphological features. Pollen grains are generally surrounded by an extremely resistant wall displaying apertures that play a key role in reproduction, being the places at which pollen tube growth is initiated. Aperture number, structure, and position (collectively termed 'aperture pattern') are determined during microsporogenesis, which is the earliest step of pollen ontogeny. Here, we review current knowledge about aperture pattern developmental mechanisms and adaptive significance with respect to plant reproduction and how advances in these fields shed light on our understanding of aperture pattern evolution in angiosperms.

Telemedicina: acercando la reumatología a la población de la zona sur / Telemedicine: bringing rheumatology to the population of the chilean south zone

La Telemedicina constituye una herramienta que permite proporcionar atención médica especializada usando la tecnología de las telecomunicaciones.Entre mayo del 2015 y julio del 2017 se realizaron 1020 atenciones a través de esta modalidad, entre el Hospital Puerto Montt (HPM) y distintos centros de Atención primaria del SS Reloncaví.Se utilizaron dos modalidades de atención: asincrónica y sincrónica con presencia virtual del paciente.Se realizaron 1020 atenciones con una resolución inmediata en el 61,7% de los casos. Esta modalidad de atención implicó un ahorro de 139.412 Km, y por concepto de pasajes de $ 10.675.200 requeridos para el desplazamiento de los pacientes desde su lugar de origen al HPM.En lugares geográficamente distantes, la Telereumatología se convierte en una herramienta fundamental que permite expandir la cobertura de atenciones de salud por especialista, reducir las listas de espera, disminuir los tiempos de traslado y el costo que estos implican.

Telemedicine constitutes a tool that allows to provide specialized medical attention using telecommunications technology.Between May 2015 and July 2017, 1,020 care were carried out through this modality, between the Puerto Montt Hospital (HPM) and different primary care centers of the SS Reloncavi.Two care modalities were used: asynchronous and synchronous with the virtual presence of the patient.1020 visits were performed with immediate resolution in 61.7% of the cases.This care modality implied a saving of 139,412 km, and for the concept of passages of $ 10,675,200 required for the movement of patients from their place of origin to the HPM.In geographically remote places, Telerheumatology becomes a fundamental tool that allows expanding the coverage of health care by specialist, reducing waiting lists, reducing travel times and the cost that these imply.

Multiple Influences of Mechanical Forces on Cell Competition.

Cell competition is a widespread process leading to the expansion of one cell population through the elimination and replacement of another. A large number of genetic alterations can lead to either competitive elimination of the mutated population or expansion of the mutated cells through the elimination of the neighbouring cells. Several processes have been proposed to participate in the preferential elimination of one cell population, including competition for limiting extracellular pro-survival factors, communication through direct cell-cell contact, or differential sensitivity to mechanical stress. Recent quantitative studies of cell competition have also demonstrated the strong impact of the shape of the interfaces between the two populations. Here, we discuss the direct and indirect contribution of mechanical cues to cell competition, where they act either as modulators of competitive interactions or as direct drivers of cell elimination. We first discuss how mechanics can regulate contact-dependent and diffusion-based competition by modulating the shape of the interface between the two populations. We then describe the direct contribution of mechanical stress to cell elimination and competition for space. Finally, we discuss how mechanical feedback also influences compensatory growth and triggers preferential expansion of one population.

Quantitative Morphological Variation in the Developing Drosophila Wing.

Quantitative genetic variation in morphology is pervasive in all species and is the basis for the evolution of differences among species. The measurement of morphological form in adults is now beginning to be combined with comparable measurements of form during development. Here we compare the shape of the developing wing to its adult form in a holometabolous insect, Drosophila melanogaster We used protein expression patterns to measure shape in the developing precursors of the final adult wing. Three developmental stages were studied: late larval third instar, post-pupariation and in the adult fly. We studied wild-type animals in addition to mutants of two genes (shf and ds) that have known effects on adult wing shape and size. Despite experimental noise related to the difficulty of comparing developing structures, we found consistent differences in wing shape and size at each developmental stage between genotypes. Quantitative comparisons of variation arising at different developmental stages with the variation in the final structure enable us to determine when variation arises, and to generate hypotheses about the causes of that variation. In addition we provide linear rules allowing us to link wing morphology in the larva, with wing morphology in the pupa. Our approach provides a framework to analyze quantitative morphological variation in the developing fly wing. This framework should help to characterize the natural variation of the larval and pupal wing shape, and to measure the contribution of the processes occurring during these developmental stages to the natural variation in adult wing morphology.

Lupus eritematoso sistémico en una zona austral de Chile / Systemic lupus erythematosus in a southern zone of Chile

Introducción. El lupus eritematoso sistémico (LES) se caracteriza por un amplio espec-tro de manifestaciones clínicas y serológicas. La última serie de enfermos chilenos fue publicada el año 1994 y contempló un total de 218 pacientes. Objetivo. Contribuir con nuevos datos epidemiológicos en una cohorte de 67 enfer-mos con LES en una zona austral de nuestro país.Pacientes y métodos. De forma retrospectiva se revisaron 100 fichas de pacientes con diagnóstico de LES realizado por médico reumatólogo del Hospital de Puerto Montt (HPM), identificados a través de registros obtenidos a contar de julio de 2013 cuando esta patología se incluyó dentro de las Garantías Explícitas en Salud (GES). 67 cumplían al menos cuatro criterios Systemic Lupus International Collaborating Clinics (SLICC) 2012 y los datos obtenidos fueron sometidos a análisis estadístico utilizando el programa SPSS versión 15.0. Resultados: 63 (94%) son mujeres. La edad promedio al momento del diagnóstico fue 38,1 años y el tiempo transcurrido desde el inicio de los síntomas fue 12,3 me-ses. Las manifestaciones clínicas más frecuentes fueron sinovitis (65.7%), alopecia (47.8%), compromiso renal (43.3%) y alteraciones cutáneas (38.8%). Sesenta (90%) tenían ANA positivo, 34 (50.7%) anti-DNA positivo y 45 (67.2%) hipocomplementemia. Se identificaron 29 (43.3%) pacientes con compromiso clínico y/o histológico renal, de los cuales a 13 se les realizó biopsia renal, correspondiente en el 69% de los casos a nefritis lúpica membrano-proliferativa.Conclusiones. Nuestra cohorte no difiere sustantivamente de otras, salvo por la baja prevalencia de manifestaciones cutáneas. Se detectó la falta de acceso a biopsia renal y exámenes serológicos autoinmunes dado principalmente por falta de profesionales idóneos en nuestra zona que permitan el acceso universal a estos procedimientos.Este estudio permite proporcionar información actualizada de pacientes con LES en una zona austral de Chile.

Introduction. Systemic lupus erythematosus (SLE) is characterized by a broad spec-trum of clinical and serological manifestations. The last series of chilean patients was published in 1994 and included a total of 218 patients.Objective. To contribute with new epidemiological data in a cohort of 67 patients with SLE in a Southern area of our country.Patients and methods. In a retrospective way, 100 records of patients diagnosed with SLE were reviewed by a rheumatologist at the Hospital de Puerto Montt (HPM), identified through records obtained as of July 2013 when this pathology was included in the Explicit Health Guarantees. (GES) 67 met at least four criteria Systemic Lupus International Collaborating Clinics (SLICC) 2012 and the data obtained were subjected to statistical analysis using the SPSS program version 15.0.Results: 63 (94%) are women. The average age at diagnosis was 38.1 years and the time elapsed since the onset of symptoms was 12.3 months. The most frequent clinical manifestations were synovitis (65.7%), alopecia (47.8%), renal involvement (43.3%) and skin alterations (38.8%). Sixty (90%) had positive ANA, 34 (50.7%) positive anti-DNA and 45 (67.2%) hypocomplementemia. We identified 29 (43.3%) patients with clinical and / or renal histological involvement, of whom 13 were under-going a renal biopsy corresponding to 69% of the cases of membranous proliferative lupus nephritis.Conclusions. Our cohort does not differ substantively from others, except for the low prevalence of cutaneous manifestations.The lack of access to renal biopsy and self-immune serological tests was detected, mainly due to the lack of qualified professionals in our area that allow universal access to these procedures.This study allows us to provide updated information on patients with SLE in a Southern zone of Chile.

Aperture number influences pollen survival in Arabidopsis mutants.

PREMISE OF THE STUDY: Pollen grains are subject to intense dehydration before dispersal. They rehydrate after landing on a stigma or when placed in humid environment by absorbing water from the stigma or surroundings. Resulting fluctuations in water content cause pollen grains to undergo significant changes in volume. Thus, morphological or structural adaptations might exist to help pollen adjust to sudden volume changes, though little is known about the correlation between pollen morphology and its ability to accommodate volume changes. We studied the effect of one morphological feature of pollen grains, the aperture number, on pollen wall resistance to water inflow in Arabidopsis thaliana. METHODS: We used three Arabidopsis thaliana mutants that differ in the number of apertures in their pollen (zero, four, or a mix of four to eight, respectively) and the wild type with pollen with three apertures. We tested pollen survival in solutions with various mannitol concentrations. KEY RESULTS: The number of intact pollen grains increased with increasing mannitol concentration for all pollen morphs tested. At a given mannitol concentration, however, an increase in aperture number was associated with an increase in pollen breakage. CONCLUSIONS: Aperture patterns, i.e., number, shape, and position, influence the capacity to accommodate volume variations in pollen grains. When subjected to water inflow, pollen grains with few apertures survive better than pollen with many apertures. Trade-offs between survival and germination are likely to be involved in the evolution of pollen morphology.

Evolutionary stasis in pollen morphogenesis due to natural selection.

The contribution of developmental constraints and selective forces to the determination of evolutionary patterns is an important and unsolved question. We test whether the long-term evolutionary stasis observed for pollen morphogenesis (microsporogenesis) in eudicots is due to developmental constraints or to selection on a morphological trait shaped by microsporogenesis: the equatorial aperture pattern. Most eudicots have three equatorial apertures but several taxa have independently lost the equatorial pattern and have microsporogenesis decoupled from aperture pattern determination. If selection on the equatorial pattern limits variation, we expect to see increased variation in microsporogenesis in the nonequatorial clades. Variation of microsporogenesis was studied using phylogenetic comparative analyses in 83 species dispersed throughout eudicots including species with and without equatorial apertures. The species that have lost the equatorial pattern have highly variable microsporogenesis at the intra-individual and inter-specific levels regardless of their pollen morphology, whereas microsporogenesis remains stable in species with the equatorial pattern. The observed burst of variation upon loss of equatorial apertures shows that there are no strong developmental constraints precluding variation in microsporogenesis, and that the stasis is likely to be due principally to selective pressure acting on pollen morphogenesis because of its implication in the determination of the equatorial aperture pattern.

Patterned Anchorage to the Apical Extracellular Matrix Defines Tissue Shape in the Developing Appendages of Drosophila.

How tissues acquire their characteristic shape is a fundamental unresolved question in biology. While genes have been characterized that control local mechanical forces to elongate epithelial tissues, genes controlling global forces in epithelia have yet to be identified. Here, we describe a genetic pathway that shapes appendages in Drosophila by defining the pattern of global tensile forces in the tissue. In the appendages, shape arises from tension generated by cell constriction and localized anchorage of the epithelium to the cuticle via the apical extracellular-matrix protein Dumpy (Dp). Altering Dp expression in the developing wing results in predictable changes in wing shape that can be simulated by a computational model that incorporates only tissue contraction and localized anchorage. Three other wing shape genes, narrow, tapered, and lanceolate, encode components of a pathway that modulates Dp distribution in the wing to refine the global force pattern and thus wing shape.

Making quantitative morphological variation from basic developmental processes: Where are we? The case of the Drosophila wing.

One of the aims of evolutionary developmental biology is to discover the developmental origins of morphological variation. The discipline has mainly focused on qualitative morphological differences (e.g., presence or absence of a structure) between species. Studies addressing subtle, quantitative variation are less common. The Drosophila wing is a model for the study of development and evolution, making it suitable to investigate the developmental mechanisms underlying the subtle quantitative morphological variation observed in nature. Previous reviews have focused on the processes involved in wing differentiation, patterning and growth. Here, we investigate what is known about how the wing achieves its final shape, and what variation in development is capable of generating the variation in wing shape observed in nature. Three major developmental stages need to be considered: larval development, pupariation, and pupal development. The major cellular processes involved in the determination of tissue size and shape are cell proliferation, cell death, oriented cell division and oriented cell intercalation. We review how variation in temporal and spatial distribution of growth and transcription factors affects these cellular mechanisms, which in turn affects wing shape. We then discuss which aspects of the wing morphological variation are predictable on the basis of these mechanisms. Developmental Dynamics 244:1058-1073, 2015. © 2015 Wiley Periodicals, Inc.

Analysis of in vitro and in vivo antioxidant properties of hydrophilic fractions from the Seaweed Halimeda Monile L

In this work, in vitro and in vivo antioxidant properties of the marine algae Halimeda monile were assessed and the levels of some of its compounds likely to be responsible for such properties were determined. The estimated contents of total polyphenols, chlorophylls a and b and carotenoids were 179.5, 356.3, 452.8 and 42.2 µg/g dry weight seaweed, respectively. The presence of terpenoids and flavonoids was also observed. The antioxidant activity of two polar fractions from H. monile (lyophilized aqueous extract and free phenolic acid fraction) was evaluated using three antioxidant assays: ferric reducing antioxidant power, 1,1-diphenyl-2-picrylhydrazyl and lipid peroxidation. Treatment of CCl4-induced liver damage in rats with extracts resulted in lower serum thiobarbituric acid-reactive substances levels and higher hepatic glutathione concentrations compared to those observed in the CCl4-treated group. Also, a significant increase in catalase activity was detected after treatment with the extracts. These results suggest that the seaweed H. monile could be a potential source for natural antioxidants.

Biomodelos para la inducción de micronúcleos en células de la médula ósea por ciclofosfamida y bleomicina / Biomodels for micronucleis induction on bone marrow cells by cyclophosphamide and bleomycin

En este trabajo se evaluó la línea de ratones Balb/c, de ambos sexos, como biomodelo en la inducción de micronúcleos en células de la médula ósea por ciclofosfamida y bleomicina. Se formaron cinco grupos experimentales/sexo: al primero se le administró NaCl al 0,9 po ciento , al segundo y al tercero ciclofosfamida y al cuarto y quinto bleomicina. Todos los medicamentos fueron suministrados por vía intraperitoneal, con diseños de tratamientos diferentes y dosis de 50 mg/kg en los tres primeros grupos y de 20 mg/kg en los dos últimos. Se obtuvo como resultado una mayor inducción de micronúcleos en eritrocitos policromáticos y un mayor índice de citotoxicidad por el uso de la ciclofosfamida, administrada en dos ocasiones antes del sacrificio, con intervalos de 24 horas entre ambas administraciones. Esto constituyó, bajo nuestras condiciones experimentales, el mejor diseño para inducir un número considerable de micronúcleos en células de la médula ósea de ratones, siendo estos resultados útiles para evaluar drogas con efecto antigenotóxico y pudiera servir también como control positivo en estudios de mutagénesis o genotoxicidad(AU)

Balb/c mice of both sexes were evaluated as biomodel in the induction of micronucleis in bone marrow cells by cyclophosphamide and bleomycin. They were divided into five experimental groups per sex. The first one was administered with NaCl 0,9 por ciento by intraperitoneal (i.p) route, the second and third groups were administered with cyclophosphamide by i.p route, with designs of different treatments at doses of 50 mg/kg. The fourth and fifth groups were administered with bleomycin by i.p route, equally in two designs of different treatments at 20 mg/kg doses. This resulted in a higher micronucleis induction of polychromatic erythrocytes and in a higher citotoxicity index with the use of cyclophosphamide administered twice before the sacrifice, with a 24-hours interval between administrations. According to our experimental conditions, this is the best design to induce a considerable number of micronucleis in bone marrow cells of mice, being useful in experimental designs to evaluate drugs with antigenotoxic effect. In addition, it implies its use according to the best found experimental design as positive control in mutagenesis and genotoxicity studies(AU)

Formation and function of a new pollen aperture pattern in angiosperms: The proximal sulcus of Tillandsia leiboldiana (Bromeliaceae).

Pollen grains are generally surrounded by an extremely resistant wall interrupted in places by apertures that play a key role in reproduction; pollen tube growth is initiated at these sites. The shift from a proximal to distal aperture location is a striking innovation in seed plant reproduction. Reversals to proximal aperture position have only very rarely been described in angiosperms. The genus Tillandsia belongs to the Bromeliaceae family, and its aperture pattern has been described as distal monosulcate, the most widespread aperture patterns recorded in monocots and basal angiosperms. Here we report developmental and functional elements to demonstrate that the sulcate aperture in Tillandsia leiboldiana is not distal as previously described but proximal. Postmeitotic tetrad observation indicates unambiguously the proximal position of the sulcus, and in vitro germination of pollen grains confirms that the aperture is functional. This is the first report of a sulcate proximal aperture with proximal germination. The observation of microsporogenesis reveals specific features in the patterns of callose thickenings in postmeiotic tetrads.

Composición química y actividad antioxidante del alga marina roja Bryothamnion triquetrum (S. G. Gmelin) Howe / Chemical composition and antioxidant activity of the red marine algae Bryothamnion triquetrum (S. G. Gmelin) Howe

En la actualidad existe un marcado interés por la búsqueda de antioxidantes de fuentes naturales, incluidas las algas marinas. El objetivo de este trabajo fue evaluar la composición química y propiedades antioxidantes del alga Bryothamnion triquetrum. Se estudió la composición centesimal y de minerales, identificación de ácidos grasos y sustancias antioxidantes. La composición centesimal es la siguiente: Proteínas (9,5 por ciento), Lípidos (1,3 por ciento), Carbohidratos (5,9 por ciento), Fibras (10,2 por ciento) y Cenizas (43 por ciento). Los resultados de la actividad antioxidante para las diferentes metodologías empleadas fueron: atrapamiento de radicales DPPHò (38 por ciento, 4 mg de liofilizado), beta-Caroteno-Linoleico (12 por ciento, 4 mg de liofilizado), actividad atrapadora de radicales O2ò- (CI50 0,36 mg/mL), de radicales OHò (CI50 2,11 mg/mL) y unión al Fe (CI50 0,37 mg/mL). Las propiedades antioxidantes de esta alga parecen explicarse por la capacidad atrapadora de radicales libres, particularmente relacionada con mecanismos de dismutación de radicales O2ò-, inactivación de radicales OHò y quelación de Fe. En trabajos previos se identificaron ácidos cinámicos y fenólicos como moléculas que pudieran explicar la actividad antioxidante, sin embargo adicionalmente se debe considerar un efecto sumatorio y/o sinérgico de otros componentes antioxidantes del extracto, como los descritos en este trabajo, incluidos minerales, carotenoides y vitamina C.

An increasing interest has been growing during the past years for the search of natural origin antioxidants, particularly those from marine algae. In this context, the main objective of current research was to evaluate the chemical composition and some antioxidant properties of the aqueous extract of the seaweed Bryothamnion triquetrum. The extracts contains: Proteins (9.5 percent), Lipids (1.3 percent), Carbohydrates (5.9 percent), Fibers (10.2 percent) and Ashes (43 percent). In current approach, the following results were obtained for the different procedures assessed: DPPHò radicals scavenging (38 percent for 4 mg of lyophilized); beta-Carotene-Linoleic assay (12 percent for 4 mg of lyophilized); O2ò- radicals scavenging (IC50 0.36 mg/mL); OHò radicals scavenging (IC50 2.11 mg/mL) and iron quelation ability (IC50 0.37 mg/mL). Thus, antioxidant properties of this natural product seem to be related to its ability to scavenge free species. In previous reports of our group, cinnamic and phenolic acids were proposed as at least partially responsible for the antioxidant properties of the extract, but the necessity for the presence of other components was also shown. Then, the antioxidant properties of the extract could be envisioned as the result of the additive and/or synergic effect between phenolic constituents and the other antioxidant components, such as minerals, carotenes and ascorbic acid.

Studies on the toxicity of Punica granatum L. (Punicaceae) whole fruit extracts.

Current investigation focuses on the toxicity evaluation of whole fruit hydroalcoholic extract of Punica granatum L. (Punicaceae), used in Cuban traditional medicine a.o. for the treatment of respiratory diseases. Previous findings on the anti-influenza activity of Punica granatum extracts has given support to the ethnopharmacological application. In our study, in chick embryo model, it was found that doses of the extract of less than 0.1 mg per embryo are not toxic. The LD50 of the extract, determined in OF-1 mice of both sexes after intraperitoneal administration, was 731 mg/kg. Confidence limits were 565-945 mg/kg. At the doses of 0.4 and 1.2 mg/kg of extract, the repeated intranasal administration to Wistar rats produced no toxic effects in terms of food intake, weight gain, behavioural or biochemical parameters, or results of histopathological studies. We conclude that toxic effects of Punica granatum fruit extract occurred at higher doses than those effective in the models where the anti-viral activity has been studied or than those doses used in Cuban folk medicine.

Modificación de la distribución de la 3H-atropina por la administración de etanol en un modelo animal / Modification of 3H-atropine by ethanol adinistration in an animal model

Se estudió la biodistribución de la 3H-atropina en ratones albinos machos heterocigóticos por administraciòn conjunta de atropina y etanol y de atropina solamente. Se observó un comportamiento cualitativamente similar en el perfil de distribución, pero se encontraron diferencias significatiovas entre los niveles de 3H-atropina en la sangre y en la casi totalidad de los tejidos, incluídos el cerebro, que es el órgano donde se producen los principales efectos. Los niveles incrementados de la atropina en la sangre y en los tejidos no parecen proceder de la modificación de su enlazamiento a las proteínas plasmáticas, sino más bien, entre otras causas, al efecto de estimulación circulatoria que produce el etanol favoreciendo la llegada de mayores cantidades de atropina a los tejidos y como consecuencia al sitio de acción, lo que provoca una respuesta más intensa que justifica el efecto de potenciación que se produce por la administración conjunta de etanol y atropina

Modificación de la distribución de la 3H-atropina por la administración de etanol en un modelo animal / Modification of 3H-atropine by ethanol administration in an animal model

Se estudió la biodistribución de la 3H-atropina en ratones albinos machos heterocigóticos por administraciòn conjunta de atropina y etanol y de atropina solamente. Se observó un comportamiento cualitativamente similar en el perfil de distribución, pero se encontraron diferencias significatiovas entre los niveles de 3H-atropina en la sangre y en la casi totalidad de los tejidos, incluídos el cerebro, que es el órgano donde se producen los principales efectos. Los niveles incrementados de la atropina en la sangre y en los tejidos no parecen proceder de la modificación de su enlazamiento a las proteínas plasmáticas, sino más bien, entre otras causas, al efecto de estimulación circulatoria que produce el etanol favoreciendo la llegada de mayores cantidades de atropina a los tejidos y como consecuencia al sitio de acción, lo que provoca una respuesta más intensa que justifica el efecto de potenciación que se produce por la administración conjunta de etanol y atropina

Efecto de la administración conjunta de etanol y atropina en ratones / Effect of siultaneous administration of ethanol and atropine in mices

Se reportaron los resultados obtenidos por la administración simultánea y con un intervalo de 30 min de etanol y atropina a ratones albinos machos, con el propósito de conocer si se produce un efecto de sinergismo o potenciación y de confirmar el efecto de la atropina sobre la mucosa gástrica. Se utilizaron las dosis de etanol y de atropina correspondientes al 50

y el 15

de mortalidad, respectivamente, obtenidas por el método de Litchfield y Wilcoxon. Al administrarse simultáneamente ambos compuestos se obtuvo un factor de asociación de 1,36 que sugiere un efecto de potenciación, y cuando se administró previamente la atropina se evidenció un efecto protector sobre la mucosa gástrica