Rosângela Felipe Rodrigues

Placentação em cutias (Dasyprocta aguti, CARLETON, M.D.): aspectos morfológicos

A cutia e um roedor silvestre, encontrado no sul da America Central e em regioes tropicais da America do Sul, principalmente nas regioes norte, nordeste e sudeste do Brasil. Estes animais fornecem proteina de origem animal e por isso, apresentam importância socio-economica para as regioes do norte e nordeste do Brasil. Para o presente trabalho foram utilizadas sete placentas de cutias (Dasyprocta aguti), em diferentes fases da gestacao. Nos aspectos morfologicos a placenta da cutia apresenta uma forma esferica e uma estrutura lobada estando conecta ao utero atraves da mesoplacenta. O fluxo sanguineo fetal flui do interlobo para o centro do lobo, ou seja, centripetamente, enquanto que o materno flui centrifugamente.

Vascularização arterial do trato gastrointestinal da Trachemys scripta elegans, Wied, 1838

Estudamos a irrigacao do esofago, ventriculo gastrico, pâncreas e intestinos de 30 tartarugas da especie Trachemys scripta elegans injetados com substância latex, onde evidenciamos duas aorta, sendo aorta direita e esquerda, que em 100,00% dos casos apresenta um trato anastomotico entre elas, ao nivel da emergencia da arteria celiaca. A arteria mesenterica cranial e responsavel pela irrigacao do jejuno, ileo, ceco, colo ascendente, colo transverso em 100,00% dos casos. Ja a arteria mesenterica caudal origina-se da arteria iliaca interna no antimero direito, em 26 preparacoes (86,60%), e no antimero esquerdo em 03 casos (13,30%). Em 01 preparacao (3,30%) a arteria mesenterica caudal, no antimero direito, origina-se a partir das arterias iliacas direita e esquerda.

Prenatal Development of the Digestive System in the Horse

Since the horse has a highly precocial reproductive strategy, most organs are functionally well developed at birth and thus, embryonic and fetal life is interesting. Data on the development of important organs are very limited. Here, we detailed macroscopically and histologically the equine digestive system, focusing on the first third of gestation. At 21 days, the oral cavity was an empty space, and the liver contained proliferating endodermal cells. At 25 days, a fusiform stomach and the pancreatic bud were present. At 28 days, a small tongue and the esophagus occurred. At 30 days, primary and secondary palates were developed, the liver contained cords of hepatocytes, and the pancreas was triangular. At 40 days, crypts had formed in the intestinal loops, cell differentiation was observed in the hepatic parenchyma, and the pancreas was elongated. Pancreatic acini and islets were observed in fetuses of 50 days and intestines were highly convoluted. Three segments of the pharynx were distinguishable at 75 days. At 105 days, the intestinal villi were wide with round tips; especially, the liver, stomach, and oral cavity showed key steps of anatomical and cellular differentiation in early fetuses, whereas other areas, such as pancreas or pharynx were still immature in the investigated phase. Pluripotency analysis using Oct4 showed initial intense staining in all of the digestive system tissues and a later decreased becoming restricted to specific cell layers. In conclusion, our data may contribute to perform a chronological reference of developmental events for approaches predicting pregnancy disorders in horses. Anat Rec, 297:1218–1227, 2014.

Ultrastructure of the bullfrog (Lithobates catesbeianus-Shaw, 1802) oviduct in different seasons

The bullfrog (Lithobates catesbeianus) is an exotic animal that adapted perfectly to the climatic conditions of Brazil after introduction in the country. These climatic conditions favor the reproduction and fattening of bullfrogs. However, the development of the bullfrog is significantly reduced in colder regions because low temperatures affect the secretion of gonadotropins and change the sensitivity of the germinal epithelium to gonadotropic hormones. Thus, the temperature and photoperiod are abiotic factors that influence the life cycle of this species, especially with regard to reproduction. Samples from different regions of the oviducts (the infundibulum, magnum, and isthmus) of 9 bullfrogs were collected in the different seasons of the year. The samples were fixed and processed for analysis with scanning and transmission electron microscopy. A comparison of the morphology of the oviducts collected during different seasonal periods suggests that the frogs have greater reproductive potential in the spring due to the development of the structures related to the oviduct, presence of developed cilia, and electron‐dense granules. However, seasonal changes were noted in the animal throughout the year in preparation for reproduction during the spring and summer. Microsc. Res. Tech. 76:523–532, 2013.

Desenvolvimento do sistema tegumentar em bovinos com idades gestacionais estimadas de 20 a 140 dias

The skin is an important part of the integumentary system, which has important functions such as protection against dehydration, injury and infection, as well as present high potential of renewal. Histologically, the skin consists of two functional layers, that are morphologically distinct, the epidermis and dermis. The mammary glands, ungueal capsule and horn are also part of this system. Due the poor data available on literature about the development of skin and other cornea attachments in bovine, the aim of this study was to describe the morphological characteristics of the integumentary system development during the embryonic and fetal periods in bovine. Individuals were allocated in three groups: Group I -embryos from 20 to 26 days (n=4), Group II -embryos from 30 to 47 days (n=6) and Group III -fetuses from 74 to 140 days (n=6). During the development of the skin it was observed different morphological patterns according to the analyzed regions. Especially, a higher level of differentiation was observed during 30-47 days of gestation. The bovine claw and mammary gland develop later between 74 to 140 days of gestation. In summary, these results related to the development of the integumentary system in bovine may help the analysis and understanding of the development of their organs, as well as the pathological disorders associated to the organogenesis.

Embryonic and Fetal Development of the Cardiorespiratory Apparatus in Horses (Equus Caballus) from 20 to 115 Days of Gestation

Horses have always sparked social and economic interest, awakening in the scientific community an interest in embryology and reproductive biology. To date, little is known about horse embryology because this species has several morphological and physiological characteristics that are peculiar to its own reproductive process. This study describes morphological aspects of developing cardiorespiratory apparatus in equine embryos and fetuses during 20-115 days of gestation. At 21 days, the equine embryo had a forming heart with two chambers and a distinct atrium and ventricle. There was a clear cellular protuberance in the lumen of both chambers and in the region of the endocardium. During this phase, the embryo had a nose rostral to the eyes and dorsal to the mouth, but no speciesspecific characteristics. Only at 40 days did it show external characteristics that were specific to the species, such as a nasal diverticulum. The larynx and pharynx were observed at 26 days of gestation. Additionally, at 26 days, the formation of the epiglottal protrusions was noted, and as embryonic development advanced, cartilage formed, while over the larynx, a non-uniform epithelial lining was observed. At day 30 of gestation, the thyroid and cricoid cartilage were seen, and the formation of the epiglottis was clear. At 45 days, the larynx was completely formed, and the thyroid, cricoid, and cricoarytenoid muscle were identified. Lung tissue was observed in embryos from 24 to 49 days, and then a pseudoglandular transitional phase started between days 50 and 60. At this time, light bronchi and terminal bronchioles were observed and became wider as the lung tissue became more vascularized. Between days 90 and 105, the primary and secondary bronchi were tubular structures composed of columnar epithelium layers. Blood capillaries were observed in the lung. Structures similar to alveoli were not seen. This work contributes to advance knowledge regarding the organogenesis of the cardiorespiratory apparatus in horses.

ORIGIN AND DISTRIBUTION OF THE BASILAR ARTERY IN THE ENCEPHALON OF ZEBUINE BOVINE FETUSES

En el presente trabajo utilizamos 30 encefalos de fetos de bovinos cruzados con cebu, inyectados con latex coloreado rojo y fijados en solucion de formaldehido al 20%, seguido de una minuciosa diseccion. La arteria basilar tiene origen a partir de la convergencia del ramo caudal de la arteria carotida del encefalo (antimeros derecho e izquierdo), en el 100% de los casos, evidenciando una disminucion progresiva de su calibre rostro-caudal. Esto sugiere que el flujo sanguineo se produciria en tal sentido, donde existen algunas ramas colaterales de la arteria basilar: arteria cerebelar caudal y arterias que se dirigen al puente y a la medula oblonga