Study of Wistar rats heart at different stages in the evolutionary cycle / Estudio del corazón de ratas Wistar en diferentes etapas del ciclo evolutivo

The rat is probably the most commonly used animal in scientific research. There are many benefits to its use such as: ability to work a large number of animals allowing greater statistical validity, the relatively short life cycles. However, the scant literature regarding the anatomy and morphology of these animals is also old and not very descriptive. The objective of this research is to study the macroscopic morphometric aspects of several parameters that have not been described yet regarding the heart of Wistar rats in different phases of their lives. Thirty-six adult male and female rats (Rattus norvegicus) weighting 150-770 g were randomly divided into 6 experimental groups. The heart was then carefully dissected and removed from the chest. After this process, the heart had their weight measured on a precision scale HELMAC HM100, and for each front section of the heart related measures were taken through a semi-automatic image analysis of Kontron Build Analyse (Minimop). The percentage ratio between the relative heart weight to body weight was between 0.5 and 0.7% in the animals with body weight up to 650 g. The maximum and minimum diameters were always statistically lower in females compared to males. The measurements showed the hearts of the females shorter, narrower, smaller and lighter than those of males. Over the life of these females, although the heart weight increases, the heart apparently keeps its shape and size. Furthermore, the hearts of males narrow and stretch along their development.

La rata es probablemente el animal más utilizado en investigaciones científicas. Hay muchos beneficios por su uso como la capacidad de trabajar con un gran número de animales permitiendo una mayor validez del punto de vista estadístico o el ciclo de vida relativamente corto del animal. Sin embargo, la escasa literatura sobre la anatomía y la morfología de la rata es antigua y no muy descriptiva. El objetivo de esta investigación fue estudiar parámetros morfométricos macroscópico no descritos con respecto al corazón de la rata Wistar en diferentes fases de la vida. Treinta y seis ratas (Rattus norvegicus) adultas, hembras y machos pesando entre 150­770 g, fueron divididas al azar en 6 grupos diferentes. El corazón fue cuidadosamente disecado y retirado del tórax. Cada corazón fue pesado en una balanza de precisión y para cada sección frontal del corazón fueron tomadas medidas relativas mediante un análisis de imágen semi-automático Kontron Build Analyse (Minimop). El porcentaje de proporción entre el peso relativo del corazón y el peso del cuerpo fue entre 0,5­0,7% en animales con peso corporal de hasta 650 g. Los diámetros máximos y mínimos fueron estadísticamente menores en hembras comparádolos con machos. Las medidas mostraron que los corazones en las hembras son más cortos, angostos, pequeños y livianos que en machos. Durante la vida de estas hembras, aunque el peso del corazón aumenta, aparentemente mantiene su forma y su tamaño. Por otro lado, los corazones de los machos se estiran y se estrechan durante su desarrollo.

Morphometric and anatomical evaluation of the heart of wistar rats / Evaluación morfométrica y anatómica del corazón de ratas wistar

The use of animals in scientific research is not recent. The rat has been used in experiments since before Christ and, in the XIX century, with the intensification of the research reports, the use of this species increased considerably. Although this fact happens, the literature regarding the heart of these animals is not very detailed and descriptive. The objective of this research is to study the macroscopic morphometric of several parameters that have not been described yet regarding the hearth of Wistar rats in different phases of their lives. Thirty-six adult male and female rats (Rattus norvegicus) weighing 150-770 g were randomly divided into 6 experimental groups: 6 animals of the group I male-weighting 150-249g (I-M); 6 animals of the group I female-weighting 150-249g (I-F); 6 animals of the group II male-weighting 250-350g (II-M); 6 animals of the group II-female­weighting (II-F); 6 animals of the group III-male weighting more than 35 g (III-M); 6 animals of the group III-female weighting more than 351g (III-F). The heart was then carefully dissected and removed from the chest. After this process, the heart had their weight measured on a precision scale HELMAC HM100, and for each front section of the heart were taken related measures through a semi-automatic image analysis of Kontron Build Analyse (Minimop). The percentage ratio between the relative heart weight to body weight was between 0.5 and 0.7 por ciento in the animals with body weight up to 650g, moreover, the wall thickness of the non-septal left ventricle was always lower for the females in all groups, while the interatrial septum have similar action in males and females and the thickness of the interventricular septum demonstrated to be similar to the wall thickness of the non-septal left ventricle.

El uso de animales en la investigación científica no es reciente. La rata se ha utilizado en experimentos desde antes de Cristo y, en el siglo XIX, con la intensificación de los trabajos de investigación, el uso de esta especie ha aumentado considerablemente. Aunque se produce lo anterior, literatura sobre el corazón de estos animales no es muy detallada y descriptiva. El objetivo de esta investigación fue estudiar la morfometría macroscópica de varios parámetros no descritos en relación con el corazón de ratas Wistar en diferentes etapas de la vida. Treinta y seis ratas adultas machos y hembras (Rattus norvegicus) con peso entre 150-770 g se dividieron al azar en 6 grupos experimentales: 6 animales del grupo I machos de ponderación 150-249g (IM), 6 animales del grupo I hembra de ponderación 150-249g (SI); 6 animales del grupo II macho de ponderación de 250-350g (II-M); 6 animales de la II-hembra-ponderación grupo (II-F); 6 animales de la ponderación III-grupo macho más de 35 g (III-M); 6 animales del grupo de ponderación III-hembra más de 351G (III-C). Posteriormente, el corazón se diseccionó cuidadosamente y se retiró del tórax. Después de este proceso, el corazón fue pesado en una balanza de precisión Helmac HM100. Para cada sección frontal del corazón se tomaron medidas relacionadas a través de un análisis de imágenes semi-automática de Kontron Build Analizar (Minimop). La relación porcentual entre el peso del corazón respecto al peso corporal fue entre 0,5 y 0,7 percent en los animales con peso corporal de hasta 650 g, por otra parte, el espesor de la pared del ventrículo izquierdo no fue siempre menor para las hembras de todos los grupos, mientras el tabique interatrial tienen acción similar en machos y hembras y el espesor del septo interventricular demostró ser similar a la del espesor de la pared del ventrículo izquierdo no septal.

Excised porcine cornea integrity evaluation in an in vitro model of iontophoretic ocular research.

BACKGROUND/AIMS: It is a challenge to adapt traditional in vitro diffusion experiments to ocular tissue. Thus, the aim of this work was to present experimental evidence on the integrity of the porcine cornea, barrier function and maintenance of electrical properties for 6 h of experiment when the tissue is mounted on an inexpensive and easy-to-use in vitro model for ocular iontophoresis. METHODS: A modified Franz diffusion cell containing two ports for the insertion of the electrodes and a receiving compartment that does not need gassing with carbogen was used in the studies. Corneal electron transmission microscopy images were obtained, and diffusion experiments with fluorescent markers were performed to examine the integrity of the barrier function. The preservation of the negatively charged corneal epithelium was verified by the determination of the electro-osmotic flow of a hydrophilic and non-ionized molecule. RESULTS: The diffusion cell was able to maintain the temperature, homogenization, porcine epithelial corneal structure integrity, barrier function and electrical characteristics throughout the 6 h of permeation experiment, without requiring CO(2) gassing when the receiving chamber was filled with 25 mM of HEPES buffer solution. CONCLUSION: The system described here is inexpensive, easy to handle and reliable as an in vitro model for iontophoretic ocular delivery studies.

Cytopathological changes induced by selected Brazilian flaviviruses in mouse macrophages.

Scanning and transmission electron microscopy were used to analyse the ultrastructure of peritoneal mouse macrophage cells infected with Brazilian flavivirus (yellow fever, Rocio, Bussuquara and Saint Louis encephalitis viruses). Macrophage cells collected 3 days after viral infection had a flattened shape, with an increased number of large spikes of cytoplasm prolongations, giving an appearance of hairy cells. Cytopathological changes to the macrophage cells were similar regardless of the infecting flavivirus. Rough and smooth endoplasmic reticulum of the macrophage cells infected with flavivirus were abundant, hypertrophic and enlarged. A large number of free ribosomes were seen in the cytoplasm of these infected cells. Spherical particles approximately 50-70 nm in diameter, some of which were empty, were observed in the cytoplasm, generally inside vesicles. These particles probably correspond to viral particles.

A vehicle for photodynamic therapy of skin cancer: influence of dimethylsulphoxide on 5-aminolevulinic acid in vitro cutaneous permeation and in vivo protoporphyrin IX accumulation determined by confocal microscopy.

Topical application of 5-aminolevulinic acid (5-ALA) followed by light irradiation is a new concept of photodynamic therapy (PDT) of skin cancers. 5-ALA is a prodrug that can be converted by the heme biosynthetic pathway into protoporphyrin IX, an effective photosensitizer. In the present work we propose the enhancement of 5-ALA-induced protoporphyrin IX accumulation by dimethylsulphoxide (DMSO) and ethylenediamine-tetraacetic acid disodium salt (EDTA). The presence of 20% DMSO (w/w) in oil-in-water emulsions increased the in vitro permeation of 5-ALA through hairless mouse skin. In vivo studies demonstrated a significant increase in the amount of protoporphyrin IX extracted from healthy hairless mouse skin after 3 h treatment with an oil-in-water emulsion containing 10% 5-ALA (w/w), 3% EDTA (w/w) and 20% DMSO (w/w). By confocal scanning laser microscopy imaging, an observed increase in red fluorescence, at 476 nm excitation and emission detected longer than 590 nm, in skin that had received this treatment, was attributed to protoporphyrin IX accumulation. Although no effect of EDTA on short-term protoporphyrin IX accumulation in skin was detected, this chelator could protect 5-ALA from decomposition during prolonged topical administration. The results obtained indicate that association of 5-ALA, EDTA and 20% DMSO may enhance the delivery of 5-ALA to the skin in the topical PDT.