Morfologia do epidídimo de cobaio (Cavia porcellus) em diferentes fases do desenvolvimento pós-natal

The morphological evolution of the epididymal duct of guinea pigs (Cavia porcellus, L.) was studied on 10, 20, 30, 45, 60, 70, 90 and 100 days of age, being complex, which is due to the proper differentiation postnatal in the epididymal epithelium. Thus, it was observed that the initial segment of the epididymis reveals an increase of epithelial height corresponding to the average height of the main tubular epithelium cells, generally progressive after 45 days of age. The epithelial height in the middle segment were higher in younger stages (10 to 45 days) than in the prepubertal age (60 days), and have a decrease among 70 to 100 days of age. The ductular terminal segment starts a gradual decrease of the epithelial heights from puberal age (70 days), until adult age (90 to 100 days). In addition, this segment showed epithelial waviness that disappeared after 70 days of age, when the lumen fills it with sperm and cellular exfoliation. The cell types of the epididymal tubular epithelium, principal cells, basal cells and apical cells, were observed in all ages. In the epididymis of very young animals, there was a predominance of undifferentiated columnar cells. After 20 days of age, there was natural prevalence of the principal cells on other cell types, what is a feature similar to other mammals.

Ocorrência de crryptosporidium spp, em animais exóticos de companhia no Brasil: Milena Sato de Souza. -

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anatomia macroscópica e ultraestrutural da orelha da paca (Cuniculus paca, Linnaeus, 1766)

Pós-graduação em Cirurgia Veterinária - FCAV

Aspectos morfológicos comparativos entre neurônios da camada I do córtex visual de duas espécies de roedores: Cavia porcellus e Rattus norvegicus

A camada I tem como característica principal a baixa quantidade de neurônios e uma alta densidade de fibras nervosas. A morfologia dos neurônios da camada I ainda é pouco estudada, tanto que nos estudos que avaliaram a morfologia desses neurônios não se chegou ainda a um consenso sobre as formas e funções desses neurônios. Este estudo avaliou a morfologia dos neurônios da camada I do córtex visual de duas espécies de roedores: Cavia porcellus, popularmente conhecido no Brasil como porquinho-da-índia e Rattus norvegicus, que é o rato e foi utilizada a linhagem Wistar, comumente usado nas pesquisas científicas. O porquinho-da-índia é um modelo animal muito estudado, utilizado em diversos segmentos da ciência. Apesar dessa espécie ser bem estudada, trabalhos na camada I desse animal são relativamente raros, especialmente em relação à morfologia e eletrofisiologia dos neurônios dessa região cortical. Pesquisas em ratos sobre os neurônios da camada I são mais frequentes, tanto em relação a morfologia quanto a eletrofisiologia. Para discriminar as possibilidades de diferenças na morfologia dos neurônios da camada I do córtex visual do porquinho-da-índia e do rato, este estudo classificou esses neurônios de acordo com a trajetória de seus dendritos e analisou as medidas dendríticas utilizando a técnica de injeção intracelular de biocitina. Após a classificação dos neurônios as comparações foram feitas entre os mesmos tipos celulares de cada roedor. Foram utilizados 35 porquinhos-da-índia da variedade Dunkin-Hartley de pêlo curto de ambos os sexos com idades de 4 a 5 dias de vida pós-natal. Quanto aos ratos, foram utilizados 30 ratos da variedade Wistar, de ambos os sexos com idades de 14 a 21 dias de vida pós-natal. Os animais foram anestesiados e tiveram seus encéfalos removidos, hemisférios separados e foram realizados cortes no plano coronal na região occipital onde se localiza a área visual dos roedores. As fatias foram mantidas em líquido cérebro-espinhal artificial e em seguida levadas ao microscópio para injeção de biocitina e posteriormente foram fixadas e tratadas para montagem em lâmina e contracoradas com Nissl para melhor visualização. Os neurônios encontrados foram classificados como: horizontais, ascendentes, descendentes e radias. Foram analisadas as seguintes medidas dendríticas: área do campo receptor, comprimento dendrítico total e médio, área total do corpo celular, número de dendritos, distância da pia-máter e análise da distribuição de Sholl. Dos resultados obtidos os mais notáveis foram o alcance dos ramos dendríticos e o tamanho do corpo celular dos neurônios da camada I do porquinho-da-índia quando comparados aos do rato. Isso sugere que, nessa espécie, um maior número de microcircuitos neurais podem ser estabelecidos, e por conseguinte maior taxa metabólica, justificada pelo maior tamanho do corpo celular.

Organisation and tyrosine hydroxylase and calretinin immunoreactivity in the main olfactory bulb of paca (cuniculus paca): a large caviomorph rodent

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular detection of Leishmania spp. in road-killed wild mammals in the Central Western area of the State of São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hypersensitivity induced in dogs by nymphal extract of Amblyomma cajennense ticks (Acari:Ixodidae)

In general, hosts develop resistance to ticks after repeated infestations; nevertheless, several studies on naturally occurring host-tick interactions were unable to detect resistance of hosts to ticks even after repeated infestations. The purpose of this investigation was to study the type of cutaneous hypersensitivity to unfed nymphal extract of A. cajennense in dogs, which, unlike guinea pigs, do not develop resistance. A first, but no second, peak in skin reaction was observed, suggesting that cellular immunity is an important mechanism of resistance to ticks. This may partially explain why guinea pigs, but not dogs, develop resistance against ticks.

Anatomia e imagenologia do braço e da coxa da Paca (Cuniculus paca, Linaeus 1776) para determinação do acesso cirúrgico à diáfise do úmero e do fêmur

Pós-graduação em Cirurgia Veterinária - FCAV

Protein Hydrolysates Are Avoided by Herbivores but Not by Omnivores in Two-Choice Preference Tests

Background: The negative sensory properties of casein hydrolysates (HC) often limit their usage in products intended for human consumption, despite HC being nutritious and having many functional benefits. Recent, but taxonomically limited, evidence suggests that other animals also avoid consuming HC when alternatives exist. Methodology/Principal Findings: We evaluated ingestive responses of five herbivorous species (guinea pig, mountain beaver, gopher, vole, and rabbit) and five omnivorous species (rat, coyote, house mouse, white-footed mouse, and deer mouse; N = 16–18/species) using solid foods containing 20% HC in a series of two-choice preference tests that used a nonprotein, cellulose-based alternative. Individuals were also tested with collagen hydrolysate (gelatin; GE) to determine whether it would induce similar ingestive responses to those induced by HC. Despite HC and GE having very different nutritional and sensory qualities, both hydrolysates produced similar preference score patterns. We found that the herbivores generally avoided the hydrolysates while the omnivores consumed them at similar levels to the cellulose diet or, more rarely, preferred them (HC by the white-footed mouse; GE by the rat). Follow-up preference tests pairing HC and the nutritionally equivalent intact casein (C) were performed on the three mouse species and the guinea pigs. For the mice, mean HC preference scores were lower in the HC v C compared to the HC v Cel tests, indicating that HC’s sensory qualities negatively affected its consumption. However, responses were species-specific. For the guinea pigs, repeated exposure to HC or C (4.7-h sessions; N = 10) were found to increase subsequent HC preference scores in an HC v C preference test, which was interpreted in the light of conservative foraging strategies thought to typify herbivores. Conclusions/Significance: This is the first empirical study of dietary niche-related taxonomic differences in ingestive responses to protein hydrolysates using multiple species under comparable conditions. Our results provide a basis for future work in sensory, physiological, and behavioral mechanisms of hydrolysate avoidance and on the potential use of hydrolysates for pest management.

Chorioallantoic and yolk sac placentation in Thrichomys laurentinus (Echimyidae) and the evolution of hystricognath rodents

The evolutionary history of Hystricognathi is associated with major transformations in their placental system. Data so far indicate that key characters are independent from size dimensions in medium to very large species. To better understand the situation in smaller species, we analyzed placental development in a spiny rat, Thrichomys laurentinus. Fourteen individuals ranging from early implantation to near term were investigated by histology, immunohistochemistry, proliferation activity and electron microscopy. Placentation in Thrichomys revealed major parallels to the guinea pig and other hystricognath rodents with respect to the early and invasive implantation, the process of trophoblast invasion, the internal organization of the labyrinth and the trophospongium as well as the establishment of the complete inverted yolk sac placenta. In contrast to systematically related small-sized species, the placental regionalization in Thrichomys was characterized by a remarkable lobulated structure and associated growing processes. Reverse to former perspectives, these conditions represented ancient character states of hystricognaths. The subplacenta was temporarily supplied by both the maternal and fetal blood systems, a rare condition among hystricognaths. The extraplacental trophoblast originating from the subplacenta was partly proliferative in mid gestation. In conclusion, the presented results indicated that only minor variations occurred in small-sized hystricognath species, independent of their systematic interrelationships. Previous views were supported that placentation in hystricognaths followed an extraordinary stable pattern, although the group had distinct habitats in South America and Africa that were separated 30-40 million years ago. J. Exp. Zool. (Mol. Dev. Evol.) 318:13-25, 2012. (C) 2011 Wiley Periodicals, Inc.

Comparison of Celsior and Perfadex lung preservation solutions in rat lungs subjected to 6 and 12 hours of ischemia using an ex-vivo lung perfusion system

OBJECTIVE: This study evaluated the performance of lungs that were preserved with different solutions (Celsior, Perfadex or saline) in an ex vivo rat lung perfusion system. METHODS: Sixty Wistar rats were anesthetized, anticoagulated and randomized into three groups (n = 20). The rats were subjected to antegrade perfusion via the pulmonary artery with Perfadex, Celsior, or saline, followed by 6 or 12 hours of ischemia (4 degrees C, n = 10 in each group). Respiratory mechanics, gas exchange and hemodynamics were measured at 10-minute intervals during the reperfusion of heart-lung blocks in an ex vivo system (IL2-Isolated Perfused Rat or Guinea Pig Lung System, Harvard Apparatus, Holliston, Massachusetts, USA; Hugo Sachs Elektronik, Germany) for 60 minutes. The lungs were prepared for histopathology and evaluated for edema following reperfusion. Group comparisons were performed using ANOVA and the Kruskal-Wallis test with a 5% level of significance. RESULTS: Gas exchange was not significantly different between lungs perfused with either Perfadex or Celsior at the same ischemic times, but it was very low in lungs that were preserved with saline. Airway resistance was greater in the lungs that were preserved for 12 hours. Celsior lungs that were preserved for 6 and 12 hours exhibited lower airway resistance (p = 0.01) compared to Perfadex lungs. Pulmonary artery pressure was not different between the groups, and no significant differences in histopathology and apoptosis were observed between the groups. CONCLUSIONS: Lungs that were preserved with Celsior or Perfadex exhibited similar gas exchange and histopathological findings. Airway resistance was slightly lower in the Celsior-preserved lungs compared with the Perfadex-preserved lungs.

Exercise Inhibits Allergic Lung Inflammation

Aerobic conditioning (AC) performed either during or after sensitization reduces allergic inflammation in mice; however, the effects of AC performed before and during allergic sensitization on airway inflammation are unknown. Mice were divided into Control, AC, OVA, and AC + OVA groups. Mice were trained in a treadmill followed by either ovalbumin (OVA) sensitization or saline administration. Peribronchial inflammation, OVA-specific IgE and IgG1 titers, the expression of Th1 and Th2 cytokines, and airway remodeling were evaluated, as well as the expression of Eotaxin, RANTES, ICAM-1, VCAM-1, TGF-beta and VEGF. Aerobic conditioning performed before and during allergic sensitization displayed an inhibitory effect on the OVA-induced migration of eosinophils and lymphocytes to the airways, a reduction of IgE and IgG1 titers and an inhibition of the expression of Th2 cytokines. The AC + OVA group also demonstrated reduced expression of ICAM-1, VCAM-1, RANTES, TGF-beta and VEGF, as well as decreased airway remodeling (p < 0.05). The effects of AC before and during the sensitization process inhibit allergic airway inflammation and reduce the production of Th2 cytokines and allergen-specific IgE and IgG1.

Development of of yolk sac inversion in Galea spixii and Cavia porcellus (Rodentia, Caviidae)

Caviomorph development includes an inverted yolk sac. Since principle processes are not understood, we investigated its differentiation in Galen and re-examined material from the guinea pig. Galea showed the typical caviomorph conditions in blastocyst development and the nature of the definitive yolk sac, formed of the visceral layer that became villous, proliferative, vascularized and attached to the uterus and placenta. In contrast to what was known before, in both species parts of the parietal yolk sac and a yolk sac cavity were temporarily present. Data suggest that early yolk sac development in caviomorphs is more complex than thought before. (C) 2012 Elsevier Ltd. All rights reserved.

Intrauterine food restriction alters the expression of uncoupling proteins in brown adipose tissue of rat newborns

A previous study from our laboratory showed that maternal food restriction (MFR) delays thermoregulation in newborn rats. In neonates brown adipose tissue (BAT) is essential for thermogenesis due to the presence of uncoupling proteins (UCPs). The aim of this study was to evaluate the influence of MFR on the UCPs mRNA and protein expression in BAT and skeletal muscle (SM) of the newborn rat. Female Wistar EPM-1 control rats (CON) received chow ad libitum during pregnancy, whereas food-restricted dams (RES) received 50% of the amount ingested by CON. Fifteen hours after birth, the litters were weighed and sacrificed. Blood was collected for hormonal analysis. BAT and SM were used for determination of UCPs mRNA and protein expression, and Ca2+-ATPase sarcoplasmic reticulum (SERCA1). RES pups showed a significant reduction in body weight and fat content at birth. MFR caused a significant increase in the expression of UCP1 and UCP2 in BAT, without changes in UCP3 and SERCA1 expression in BAT and SM. No differences between groups were found for leptin, T4 and glucose levels. RES pups showed increased insulin and decreased T3 levels. The delay in development of thermoregulation previously described in RES animals appears not to result from impairment in thermogenesis, but from an increase in heat loss, since MFR caused low birth weight in pups, leading to greater surface/volume ratio. The higher expression of UCP1 and UCP2 in BAT suggests a compensatory mechanism to increased thermogenesis. (C) 2011 Elsevier Ltd. All rights reserved.

SCG postnatal remodelling - hypertrophy and neuron number stability - in Spix's Yellow-toothed Cavies (Galea spixii)

Whilst a fall in neuron numbers seems a common pattern during postnatal development, several authors have nonetheless reported an increase in neuron number, which may be associated with any one of a number of possible processes encapsulating either neurogenesis or late maturation and incomplete differentiation. Recent publications have thus added further fuel to the notion that a postnatal neurogenesis may indeed exist in sympathetic ganglia. In the light of these uncertainties surrounding the effects exerted by postnatal development on the number of superior cervical ganglion (SCG) neurons, we have used state-of-the-art design-based stereology to investigate the quantitative structure of SCG at four distinct timepoints after birth, viz., 1-3 days, 1 month, 12 months and 36 months. The main effects exerted by ageing on the SCG structure were: (i) a 77% increase in ganglion volume; (ii) stability in the total number of the whole population of SCG nerve cells (no change - either increase or decrease) during post-natal development; (iii) a higher proportion of uninucleate neurons to binucleate neurons only in newborn animals; (iv) a 130% increase in the volume of uninucleate cell bodies; and (v) the presence of BrdU positive neurons in animals at all ages. At the time of writing our results support the idea that neurogenesis takes place in the SCG of preas, albeit it warrants confirmation by further markers. We also hypothesise that a portfolio of other mechanisms: cell repair, maturation, differentiation and death may be equally intertwined and implicated in the numerical stability of SCG neurons during postnatal development. (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.