PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Agoutis are small-sized wild animals whose body weight can reach up to 4kg, and are found throughout Brazil. They are considered important seed dispersers, especially for big trees and there are species that rely almost exclusively on these animals for their territorial distribution. The objective of the present study was B scan and Doppler ultrasound characterization of the abdominal organs of healthy agoutis reared in captivity. Fifteen agoutis, chemically restrained, were used from the Nucleus for Wild Animal Studies and Conservation (Núcleo de Estudos e Preservação de Animais Silvestres - NEPAS), CCA-UFPI, submitted to B scan and Doppler ultrasound examination. The urinary bladder wall was hyperechogenic, thin, smooth and regular throughout its anatomic path, with 0.09±0.03cm mean thickness. The kidneys showed fine and homogeneous echotexture, preserved global echogenicity, hyperechogenic in relation to the spleen and isoechogenic or discreetly hyperechogenic in relation to the liver. The spectral Doppler trace showed systolic and diastolic peaks, wide and thread-like, with low flow resistance and a continuous and full diastolic portion that decreased gradually during the diastole (75.83±1.42cm/s, for the right kidney and 80.43±1.22cm/s, for the left kidney). The right adrenal gland was 0.61-1.18cm long and 0.17-0.32cm in diameter, while the left adrenal gland was 0.62-1.16 long with 0.14-0.25cm diameter. The agouti spleen was filiform in shape, with pointed poles and 1.02±0.18cm in diameter. The agouti liver occupied all the abdominal cavity cranial space in direct contact with the diaphragm. The intrahepatic vascular flow allowed individualization of the portal vein (PV) and hepatic vein (HV). The portal veins were distinguished from the hepatic veins mainly by their wall echogenic pattern. The pancreas was 0.51±0.1 cm thick and the pancreatic duct measured 0.12±0.02cm. The stomach was placed to the left the spleen and to the right of the proximal intestine and the transversal colon and the walls were 0.16±0.05cm thick. The abdominal aorta was 0.43±0.04cm in diameter and showed 95.2±2.16cm/s vascular flow. This study characterized agouti organs and abdominal blood vessels by B scan and Doppler ultrasound, that permitted definition of the size, shape, position, echogenicity and echotexture of the anatomic constituents and established reference values for the vascular network and blood flow in the species.

• Abdominal B-mode Doppler ultrasonography agouti Dasyprocta prymnolopha ultrasound morphology hemodynamic Hystricomorpha

Abstract in Portuguese:

As cutias são animais silvestres de pequeno porte, cujo peso corpóreo pode chegar até 4kg, e existem em todo território brasileiro. São considerados importantes dispersores de sementes, especialmente para árvores de grande porte, existindo espécies que dependem quase que exclusivamente destas para sua distribuição territorial. Este trabalho teve por objetivo a caracterização ultrassonográfica modo B e Doppler dos órgãos abdominais de cutias hígidas criadas em cativeiro. Foram utilizadas 15 cutias, contidas quimicamente, oriundas do Núcleo de Estudos e Preservação de Animais Silvestres – NEPAS, CCA-UFPI, submetidas a exame ultrassonográfico em modo B e Doppler. A parede da vesícula urinária presentou-se hiperecogênica, fina, lisa e regular em todo seu trajeto anatômico, com espessura média de 0,09±0,03cm. Os rins demonstraram ecotextura fina e homogênea, ecogenicidade global preservada, hipoecogênico em relação ao baço e isoecogênico ou discretamente hipoecogênico em relação ao fígado. O traçado em Doppler espectral mostrou pico sistólico e diastólico, amplo e afilado, exibindo baixa resistência de fluxo, com uma porção diastólica contínua e cheia, que diminui gradativamente no decorrer da diástole (75,83±1,42cm/s para o rim direito e 80,43±1,22 cm/s para o esquerdo. A adrenal direita apresentou uma variação de comprimento entre 0,61 a 1,18cm e diâmetro variando entre 0,17 a 0,32cm, enquanto a adrenal esquerda evidenciou comprimento de 0,62 a 1,16 e diâmetro de 0,14 a 0,25cm. O baço das cutias mostrou formato filiforme, com polos pontiagudos e diâmetro de 1,02±0,18cm. O fígado da cutia ocupa todo o espaço cranial da cavidade abdominal, em contato direto com o diafragma. O fluxo vascular intrahepático permitiu individualizar as veias porta (VP) e veias hepáticas (VH). As veias porta foram distinguidas, particularmente pelo padrão ecogênico de suas paredes, quando comparadas com as veias hepáticas. A espessura do pâncreas foi de 0,51±0,1cm e o ducto pancreático mediu 0,12±0,02cm. O estômago relaciona-se à esquerda com o baço e a direita com o duodeno proximal e colón transverso. Sua espessura de parede mensurada foi de 0,16±0,05cm. A aorta abdominal possui diâmetro de 0,43±0,04cm e fluxo vascular de 95,2±2,16cm/s. Este estudo caracterizou os órgãos e vasos sanguíneos abdominais de cutias, por meio de ultrassonografia modo B e Doppler, o que permitiu definir o tamanho, formato, posição, ecogenicidade, ecotextura dos constituintes anatômicos, além de estabelecer valores de referência para a rede vascular e fluxo sanguíneo na espécie.

• Ultrassonografia abdominal Modo B Doppler cutias Dasyprocta prymnolopha ultrassom hemodinâmica abdome morfologia Hystricomorpha

Abstract in English:

ABSTRACT.- Conceição R.A., Ambrósio C.E., Martins D.S., Carvalho A.F., Franciolli A.L.R., Machado M.R.F., Oliveira M.F. & Miglino M.A. 2008. [Morphological aspects of yolk sac from rodents of Hystricomorpha subordem: paca (Agouti paca) and agouti (Dasyprocta aguti).] Aspectos morfológicos do saco vitelino em dois roedores da subordem Hystricomorpha: paca (Agouti paca) e cutia (Dasyprocta aguti). Pesquisa Veterinária Brasileira 28(5):253-259. Setor de Anatomia dos Animais Domésticos e Silvestres, Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia. Universidade de São Paulo, Cidade Universitária, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-900, Brazil. E-mail: ceambrosio@usp.br The study aimed to characterize gross and microscopic features of the yolk sac in paca (Agouti paca) and agouti (Dasyprocta aguti) in early gestation. Fragments of the yolk sac of 3 paca and 3 agouti fetuses at early gestation were taken and processed for histological and ultrastructural analyses. Gross features of the vitelline placenta in both species showed its insertion over the main placenta surface and projections to the embryos/fetuses. Microscopically, the vitelline placenta was constituted by endoderm epithelium and mesenchyme, in which vitelline vessels are abundant. The ultrastructure of the samples showed that the visceral yolk sac of the paca was formed by endodermic cells with nuclei in the median region, and that the visceral yolk sac of the agouti was formed by nuclei arranged apically; other characteristic was the large number of mitochondrias, eletrodense vesicles with microvilosities We conclude that (1) the vitelline placenta of the two species presents insertion in the surface of the main placenta; (2) the vitelline placenta of paca rests on the Reichert’s membrane, whereas the agouti vitelline placenta does not have this membrane; (3) the chorion and allantoic are fusioned; and (4) the chorioallantoic placenta and the yolk sac in both species are reversed and vascularized.

• Hystricomorpha Agouti paca Dasyprota aguti yolk sac

Abstract in Portuguese:

ABSTRACT.- Conceição R.A., Ambrósio C.E., Martins D.S., Carvalho A.F., Franciolli A.L.R., Machado M.R.F., Oliveira M.F. & Miglino M.A. 2008. [Morphological aspects of yolk sac from rodents of Hystricomorpha subordem: paca (Agouti paca) and agouti (Dasyprocta aguti).] Aspectos morfológicos do saco vitelino em dois roedores da subordem Hystricomorpha: paca (Agouti paca) e cutia (Dasyprocta aguti). Pesquisa Veterinária Brasileira 28(5):253-259. Setor de Anatomia dos Animais Domésticos e Silvestres, Departamento de Cirurgia, Faculdade de Medicina Veterinária e Zootecnia. Universidade de São Paulo, Cidade Universitária, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-900, Brazil. E-mail: ceambrosio@usp.br The study aimed to characterize gross and microscopic features of the yolk sac in paca (Agouti paca) and agouti (Dasyprocta aguti) in early gestation. Fragments of the yolk sac of 3 paca and 3 agouti fetuses at early gestation were taken and processed for histological and ultrastructural analyses. Gross features of the vitelline placenta in both species showed its insertion over the main placenta surface and projections to the embryos/fetuses. Microscopically, the vitelline placenta was constituted by endoderm epithelium and mesenchyme, in which vitelline vessels are abundant. The ultrastructure of the samples showed that the visceral yolk sac of the paca was formed by endodermic cells with nuclei in the median region, and that the visceral yolk sac of the agouti was formed by nuclei arranged apically; other characteristic was the large number of mitochondrias, eletrodense vesicles with microvilosities We conclude that (1) the vitelline placenta of the two species presents insertion in the surface of the main placenta; (2) the vitelline placenta of paca rests on the Reichert’s membrane, whereas the agouti vitelline placenta does not have this membrane; (3) the chorion and allantoic are fusioned; and (4) the chorioallantoic placenta and the yolk sac in both species are reversed and vascularized.