Histomorphometric adaptation of yak (Bos grunniens) abomasum to the Qinghai-Tibetan plateau environment / Adaptación histomorfométrica del abomaso de yak (Yos grunniens) al medio ambiente de la meseta tibetana Qinghai

Six abomasums of yaks (Bosgrunniens) were studied with gross dissection and histological methods. It was found that the mucosa of the yak abomasum was covered with simple columnar epithelium. There were lots of spiral folds (10) in the fundic glandular area. The developed membrane of lamina propria was occupied by high density glands. According to the morphological characteristics of the glands, the abomasum was divided into the cardiac, gastric and pyloric glands. Cardiac glands were curved tubular glands with the intumescent bottom and small glandular cavity. Fundic glands were simple tubular glands or branched tubular glands, where the chief, parietal and mucous neck cells can be observed clearly. Pyloric glands were curled tubular glands, the closer to the deep of the lamina propria, the more obvious the glands curl. Staining of glycoconjugate revealed that the mucosal epithelium of the cardiac gastric and pyloric glands and gastric pits epithelium mainly secreted neutral glycoconjugate, but other portions of cardiac and gastric glands secreted mixed and acid glycoconjugate respectively. By Gordon-Sweet's reticular fiber staining, it was found that the mucous neck cells possessed the characteristic of argyrophilic phenomenon. There was a large number of argyrophilic granules in the supranuclear cytoplasm in contrast with the chief cells. Furthermore, there were isolated lymphoid nodules and diffuse lymphoid tissue in the abomasum glands, especially in corpus abomasi. Grimelius silver staining showed that the argyrophil cells were located in the glandular epithelium and lamina propria of glands, which can also be observed in connective tissue. These endocrine cells dispersed individually in epithelial cells, occasionally in 3­5 cell groups. Therefore, the yaks were grazed throughout the year on diverse natural grassland and had evolved morphological characteristics of the abomasum enabling them to consume a wide variety of plant species, thereby better adapting them to harsh plateau environment.

Seis abomaso yak (Bosgrunniens) fueron estudiados con disección y métodos histológicos. Se encontró que la mucosa del abomaso yak estaba cubierta de epitelio columnar simple. Se observaron pliegues en espiral (10) en la zona glandular fúndica. La membrana desarrollada de la lámina propia contenía glándulas de alta densidad. De acuerdo con las características morfológicas de las glándulas, el abomaso se dividió en las glándulas cardíacas, gástricas y pilórica. Las glándulas cardíacas se curvan en glándulas tubulares con la parte inferior intumescente y una pequeña cavidad glandular. Las glándulas fúndicas eran glándulas tubulares simples o glándulas tubulares ramificadas, donde se pueden observar con claridad las células principales, parietales y mucosas del cuello. Las glándulas pilóricas fueron glándulas tubulares curvadas, cuanto más cercanas a la lámina propia, más evidente fue su forma ondulada. La tinción glucoconjugada reveló que el epitelio de la mucosa de las glándulas gástricas cardiacas, pilóricas y el epitelio de las fosas gástricas secretaron principalmente un glucoconjugado neutro, pero otras porciones cárdicas y de las glándulas gástricas secretaron un glucoconjugado mixto y ácido, respectivamente. A la tinción de fibras reticulares, se encontró que las células mucosas del cuello poseían características argirófilas. Se observó un gran número de gránulos en el citoplasma supranuclear en contraste con las células principales. Además, no fueron aislados los nódulos linfoides y presentaba tejido linfoide difuso en las glándulas de abomaso, especialmente en el cuerpo del abomaso. La tinción Gordon Sweet indicó que las células argirofílicas se localizaron en el epitelio y lámina propia glandular, lo que también se observó en el tejido conectivo. Estas células endocrinas se dispersan individualmente en las células epiteliales, de vez en cuando en grupos celulares de 3-5. De esta forma, los yak pastorean durante todo el año, en diversos pastizales naturales, y han evolucionado sus características morfológicas que les permiten consumir una amplia variedad de especies de plantas, con lo que se adaptan mejor a las condiciones inhóspitas.

Avaliação morfológica do abomaso e ceco-cólon de bovinos / Morphologic evaluation of the abomasum and cecum-colon of bovines

A morfofisiologia relacionada à absorção de ácidos graxos voláteis (AGV) ao longo do trato gastrintestinal de ruminantes não é totalmente caracterizada. Desse modo, os objetivos deste trabalho foram mensurar a extensão da superfície de absorção e determinar o índice mitótico (IM) do abomaso, do ceco e da alça proximal do cólon ascendente (APCA). Dez bovinos mestiços adultos tiveram seu estômago e intestino grosso removidos imediatamente após o abate. A área total da superfície de absorção foi mensurada por meio de digitalização e análise de imagens. Cortes histológicos foram feitos para determinação do IM. A superfície absortiva do abomaso, 0,58m², foi menor (P<0,01) do que a do rúmen, 6,53m², e a do omaso, 2,31m². A superfície absortiva do ceco e da APCA, 0,23m², correspondeu a 3,5% da superfície do rúmen e a 10% da superfície do omaso. O IM observado foi 0,48%; 0,14%; 0,36% e 0,41% para as regiões de pregas espirais, pilórica, ceco e APCA, respectivamente. Observou-se correlação positiva entre a massa tecidual do abomaso e a área de superfície de absorção, aspecto também observado no ceco-APCA. Foi possível estabelecer regressões para facilitar a mensuração da superfície absortiva do abomaso e do ceco-APCA.

The morphology and physiology related to volatile fatty acid (VFA) absorption throughout the gastrointestinal tract of ruminants is not totally characterized. The purpose of this work was to measure the abomasum and cecum-colon absorptive surface extension and determine the mitotic index (MI). Ten adult crossbred bovine had their stomach and large intestine removed after slaughter. The total area of the absorptive surface was measured through image capture and analysis. Histological sections were performed to measure the MI. The abomasum absorptive surface (0.58m²) was lower (P<0.01) than that of the rumen (6.53m²) and omasum (2.31m²). The cecum-colon absorptive surface (0.23m²) corresponded to 3.5% of the rumen and 10% of the omasum. The MI observed was 0.48%; 0.14%; 0.36% and 0.41% for the regions of spiral folds, pyloric, cecum and proximal loop of ascending colon, respectively. A positive correlation between abomasum tissue mass and the abomasum absorptive surface was observed. This phenomenon has also occurred in the cecum and colon. It was possible to establish regressions to facilitate measurements of the absorptive surface of the abomasum and cecum-colon.

Desenvolvimento do abomaso de bovinos no período pré-natal / Development of bovine abomasum in prenatal period

Para esta pesquisa, amostras de abomaso de fetos da raça Nelore (Bos taurus indicus) foram divididos em cinco grupos: 1º – fetos com 9 a 15 semanas (8 a 21cm) de gestação, 2º – fetos com 16 a 22 semanas (23 a 37 cm), 3º – fetos com 23 a 29 semanas (40 a 58 cm), 4º – fetos com 30 a 36 semanas (61 a 77 cm) e 5º – fetos com 37 a 43 semanas (79 a 88 cm). Os cortes histológicos foram corados com Hematoxilina e Eosina, picrossirius e Tricrômico de Mallory e examinados ao microscópio de luz. No feto de 11 cm, observaram-se pregas mucosas largas, vilosidades revestidas por epitélio simples cilíndrico, lâmina própria, tela submucosa, túnica muscular com estratos interno e externo e serosa. Aos 13,5 cm, as vilosidades eram evidentes com formação da lâmina muscular da mucosa. Aos 16,5 cm, houve aumento em número e tamanho das glândulas mucosas. No feto de 26 cm, observou-se aumento das túnicas e ramificações das glândulas. Aos 29 cm, observou-se aumento no tamanho das pregas. Com 37 cm, houve aumento do epitélio glandular, lâmina muscular da mucosa e túnica muscular. Com 42 cm, as glândulas eram profundas com células mucosas e lâmina pró- pria delgada. Concluiu-se que as os valores histomorfométricos da túnica muscular e parede total do abomaso foram crescentes para todos os grupos, com exceção dos grupos 4 e 5 para os quais houve queda dos valores, sem diferença significante e não houve crescimento contínuo para os demais constituintes da parede do abomaso.

For this purpose, samples of Nelore fetus abomasum (Bos taurus indicus) were classified into five groups: 1 – fetuses with 9 to 15 weeks (8 to 21 cm) of gestation, 2 – fetuses with 16 to 22 weeks (23 to 37 cm), 3 – fetuses at 23 to 29 weeks (40 to 58 cm) 4 – fetuses with 30 to 36 weeks (61 to 77 cm) and 5 – fetuses with 37 to 43 weeks (79 to 88 cm). Histologic sections were stained with Hematoxylin and eosin, picrosirius and Mallory’s trichrome methods and examined underlight microscopy. In fetus with 11 cm of length showed deep mucosa, wide folds and villi lined by single cylindrical epithelium, lamina propria, submucosa, muscular sublayers and serosa. Fetus with 13.5 cm, villi were evident and muscular layer of the mucosa was formed. At 16.5 cm, could be seen an increase in mucosa glands size and number. In fetus of 26 cm, showed gastric mucous glands at great number and ramifications. At 29 cm large folds, were observed.At 37 cm, showed glandular epithelium, muscular layer of the mucosa and muscular layer well development. Fetus with 42 cm, showed deep glands with corresponding mucous cells surrounding by thin lamina propria. It was concluded that the histomorphometric values of muscular layer and total abomasum wall were increased for all groups except for groups 4 and 5 which there was a decline of values, without presenting a significant difference and there was no continuous pattern of growth for other components of abomasum wall.

Anatomical and histological study of the omaso-abomasal orifice in cow

For macroscopic and microscopic study of the omaso abomasal orifice the omasums and abomasums of ten fresh healthy cows between 12-18 months were used. Five of them for macroscopic observation of the orifice and the others for micrscopic study were used. For the later purpose tissues were cut from the cranial lateral and visceral sides and 5x5mm samples were fixed in 10% buffered formalin. Routine histologic method were used and 6 micro m paraffin sections were stained by haematoxylin eosin and studied under light microscope. The lengths of the mucosa, mucosal glands and the muscularis layer measured by graticule and the datas were analyzed statistically by the Anova test. By the study on the muscular layers at the different parts of the orifice and compare it with the other parts the abomasums it seems that the sphincteric function of the pilla omasi is the main role for closure of the orifice vela abomasica were helped to it to be completely closed