This paper described the architecture of the dog aortic arterial wall focused in the ascendant; thoracic descendent, and abdominal parts of the aorta. Furthermore, in this study we analyzed the wall structure of the right external iliac artery and the left vertebral artery of dog aiming to compare their architectural patterns with the aortic wall mainly in abdominal aortic part, which was structured by a mixed muscular and connective matrix equilibrated elements. The variables analyzed were the thickness of each mural layer; the number of elastic lamellae, mainly localized into the medial layer structure, and the diameters of each aortic segment. The aortic structure showed a typical elastic pattern in the ascendant and descendant thoracic parts, but in its abdominal segment a lesser presence of elastic lamellae permitted to classify it with a mixed mural composition. The aortic segments mainly presented variable amounts of smooth muscle cells and connective matrix assuming a meshwork pattern. Furthermore, smooth muscle cells were seen intermingled with connective lamellae and fibers forming the complex meshwork related, which certainly helped to guarantee the aortic mural integrity during the aortic blood flow.

El objetivo de este trabajo fue describir la estructura histológica de la aorta del perro adulto, a través del análisis morfométrico. Fueron estudiados los tres segmentos de la aorta, ascendente y descendente torácicos, y el segmento abdominal inferior a los riñones. Esta última porción presentó un patrón estructural mixto, con tejido muscular liso y conectivo, con equilibrio entre las células musculares lisas y el componente mural tipo estroma, con elementos fibrosos y laminillas elásticas. En las otras partes de la aorta, se observó el clásico patrón elástico en la estructura mural, con una mayor proporción de los componentes activos (musculares lisos) que los pasivos, o sea, laminillas y fibras conectivas. El número de las laminillas elásticas fue decreciente desde la aorta ascendente en dirección a la parte abdominal de la aorta. Los diámetros de los tres segmentos tiñeron de manera similar. La comparación entre la estructura mural de la aorta y la histología de la arteria iliaca interna derecha y arteria subclavia izquierda, ambas musculares, fueron analizadas de manera objetiva, encontrando diferencias en el patrón mural aórtico, principalmente en el segmento aórtico terminal.

O epitélio de revestimento da cauda epididimária em cães sem raça definida foi examinado através da microscopia eletrônica de transmissão. O epitélio epididimário é pseudoestratificado com estereocílios na borda luminal e é composto principalmente por células principais e claras. Além destes tipos, foi observado algumas células basais e apicais. As células principais e claras apresentaram características ultra-estruturais que sugerem que as mesmas estão envolvidas com funções absortivas e secretórias. Os resultados foram comparados com estudos prévios realizados na cauda do ducto epididimário de outros mamíferos, com o objetivo de melhor entender o papel do epidídimo na maturação espermática.

The epithelium lining of cauda epididymidis in mongrel dogs was examined by transmission electron microscopy. The epididymal epithelium is pseudostratified with stereocilia and is composed predominantly of principal and clear cells. Therefore, exist basal and apical cells. The principal and clear cells show features suggesting that they may be preferentially involved in absorptive and secretive functions. These results are compared with previously published data on the cauda epididymidis of other mammalian species, in order to understand the significance of the epididymis in sperm maturation.

The surface epithelium of the vas deferens of Agouti paca, a wild and large South American rodent, was basically formed by principal and basal cells being only the principal cells related to endocytosis processes and also secretion taking base on their cytoplasmic ultrastructural features. Principal cell of vas deferens epithelium were characterized mainly by presence of vesicles with several shapes, sizes and internalized content at their apical cytoplasm occurring smaller pits and pale small vesicles seen next to the apical brush border of microvillus. Moreover, coated vesicles, smooth surface vesicles and great vesicles; multivesicular bodies, endosomes and lysosomes were seen. Presence of an apocrine secretory apparatus was also viewed, showing apical cytoplasmic expansions protruding into the vas deferens luminal compartment. The basal flattened cells, without luminal surface contact, occurred next to the basement membrane of the ductus, and did no exhibit special ultrastructural features.

El epitelio que recubre la luz del conducto deferente de la laca (Agouti paca), un roedor silvestre de Sudamérica, está formado por células principales (P) y básales (B), en donde las células principales están asociadas a los procesos de endocitosis y secreción, teniendo una base en su característica ultraestructural citoplasmática. Las células principales de los vasos deferentes del epitelio se caracteriza principalmente por la presencia de vesículas con variadas formas, tamaños y contenido interior en su citoplasma apical produciendo pequeñas invaginaciones y pequeñas vesículas pálidas ubicadas continuas al borde en cepillo de las microveilosidades apicales. Además, fueron observados, vesículas de superficie lisa y vesículas de gran tamaño; órganos multivesiculares, endosomas y lisosomas. También se observó la presencia de un aparato secretor apocrino, con expansiones citoplasmáticas apicales que se protruyen en el compartimiento luminar del conducto deferente. Células básales aplanadas, sin contacto con la superficie luminal, se encuentran junto a la membrana basal del conducto, las que no presentan características ultraestructurales especiales.

O ducto epididimário (DE) de codorna doméstica mostrou, ao longo do ano, variabilidade pequena, porém muito expressiva no outono, o qual corresponde à fase quiescente do ciclo testicular anual. A morfologia do DE na primavera foi, em termos, similar à verificada no verão e inverno. Nestas fases notaram-se aumento significante do calibre tubular do DE; estocagem intraluminal de espermatozóides e ocorrência de mitocôndrias, lamelas do RE, vesículas variáveis quanto à forma, dimensões e conteúdos e presença de alguns lisossomos localizados, principalmente, no citoplasma apical das células principais (P), no epitélio epididimário. Estas características ultra-estruturais das células P parecem ser indicativas da ocorrência de processos ativos de endocitose e de secreção micromerócrina. A quiescência outonal foi caracterizada pelo aspecto anfractuoso do DE; ausência de espermatozóides e pouco material intraluminal, observados à microscopia de luz. Características ultra-estruturais degenerativas foram verificadas ao nível do citoplasma supranuclear das células P epididimárias no outono.

Small but expressive variability was noted on the epididymidis duct (ED) of domestic quail along the year, with more evidence in autumn of the quiescent phase of the annual testis cycle in this species. Spring features of ED had a general similar pattern in summer and winter. They were characterized by enlargement of epididymis tubule, storage of spermatozoa into the luminal compartment and presence of mitochondria, ER lamellae, several variable vesicles, and lysosomes localized mainly on the apical cytoplasm of principal cells (P) of the epididymal epithelium. These P cells features indicated a process of endocytosis and perhaps protein secretion. Autumn quiescence was marked by a convolute pattern of the epididymis tubule, lacking of spermatozoa and small amount of exfoliate heterogeneous material inside the luminal compartment at light microscopy. Ultrastructural degenerative features mainly apical cytoplasmic debris were seen in the supranuclear cytoplasm of lining P cells.

The concentration of total protein measured by photocolorimetric methodology and reported as units per 100 mg of tissue decreased from the initial segment to the cauda epididymidis of the Golden hamster, being significant the numeric difference observed between these two regions. This observation was related with an increased synthesis and secretion of proteins to the lumen in proximal segments of the epididymidis duct, mainly in initial segment, as proposed for other rodents. LDH activity was higher in initial segment and distal cauda than in the caput and corpus epididymidis, although no significant differences in mean values had been observed. The high LDH activity observed in initial segment and cauda epididymidis of hamster had been related to an expressive epithelium metabolic activity presented in these regions. This metabolic activity help to guarantee the survival of spermatozoa stored in cauda epididymidis. Furthermore, lower LDH activity noted in the caput and corpus epididymidis might be related with a progressive reduction of glycolysis in initial maturation step of spermatozoa mainly verified in corpus epididymidis.

La concentración de proteínas totales medidas a través de la fotocolorimetría y reportada como unidades por 100 mg de tejido, decreció desde el segmento inicial hacia la cola del epidídimo del hámster dorado, siendo significativa la diferencia numérica observada entre estas dos regiones. Esta observación estaba relacionada con el aumento de la síntesis y secreción de proteínas por el epitelio del epidídimo, siendo exportadas después hacia el lumen tubular en los segmentos proximales del epidídimo, especialmente a nivel del segmento inicial, ya obsevada en otros roedores. La actividad del LDH fue mayor en el segmento inicial y en la cola distal que en la cabeza y cuerpo del epidídimo, no obstante no haya sido observada ninguna diferencia significativa en los valores promedios. La intensa reacción del LDH observada en el segmento inicial y cola del epidídimo había sido relacionada con la expresiva actividad metabólica del epitelio, especialmente observada en estas regiones del conducto. Esta actividad metabólica permite la sobrevivencia y el metabolismo de los espermatozoides almacenados en la cola del epidídimo. Además, la baja actividad del LDH evidenciada en la cabeza y el cuerpo del epidídimo podría estar relacionada con la reducción progresiva de la glucólisis observada en la etapa inicial de maduración de los espermatozoides, siendo especialmente notoria en el cuerpo del epidídimo

Light microscopy analysis of the mural structure of the common carotid artery, internal carotid artery and external carotid artery in mongrel dog revealed variability in the middle values of vascular diameter and thickness of the intimal plus medial coats and adventitial coat. The vascular diameter did not differ between the internal carotid artery and external carotid artery, but was significantly increased in the common carotid artery from which the other two arteries had origin. The increased thickness of the intimal plus medial coats of the common carotid artery revealed the constant mechanical adjustment of the arterial wall and local shearing stress that occurred among the arterial coats. The adventitial coat of the internal carotid artery was significantly thicker than those of the common carotid and external carotid arteries, with no significant difference noted between the latter arteries. These histomorphometric results were related to the qualitative observations regarding the mural structure of the three arteries analyzed, especially regarding to the increased thickness and structural complexity of the adventitial coat of the internal carotid artery. Perhaps it acted as an external protective sheath of the vascular wall during its long course until the carotid channel

El análisis de la estructura de las arterias carótidas, común, externa y interna en el perro sin raza definida, a través del microscopio fotónico mostró variabilidad en los valores promedios de los parámetros: diámetro vascular y grosor de las capas íntima, media y adventicia de cada arteria, respectivamente. El diámetro vascular no difirió significantemente entre las arterias carótidas interna y externa, pero mostró aumento significativo en la arteria carótida común, la cual da origen a los dos otros vasos sanguíneos. El grosor aumentado de las capas íntima y media de la arteria carótida común, más directamente sometida a la fuerza de la presión sistólica cardiaca, significó los ajustes constantes de la pared vascular a las alteraciones de presión y al estrés de deslizamiento controlado entre las capas de la pared arterial. El grosor de la adventicia de la arteria carótida interna fue significativamente mayor que la de las otras arterias carótidas (común y externa), las cuales, entre, sí no tuvieron diferencia con respecto de la adventicia. Estos resultados morfométricos estaban directamente correlacionados con las observaciones morfológicas de naturaleza cualitativa, especialmente, en relación al incremento relativo de la adventicia de la carótida interna ya apreciable en las microfotografías. Tal vez, la adventicia en la arteria carótida interna actúa como una capa conjuntiva protectora, durante el complejo proceso de avance de esta arteria desde su origen cervical hasta el nivel del canal carotídeo donde alcanza la cavidad craneana