RESUMO
The liver has multiple functions that change throughout ontogeny. South American camelids (SAC) have unique characteristics related to adaptation to extreme environments and metabolism. However, the process of hepatic cell differentiation has not been studied in any SAC. We study the patterns of cell differentiation and proliferation in the liver of the alpaca at different times of the ontogeny, excluding the hematopoietic components. Immunohistochemical techniques were performed in 66 specimens, including embryos, fetuses, neonates and adults. Supplementary analyses were performed by lectinhistochemistry. The hepatocytic differentiation was performed by the identification of Hepatocyte (Clone: ââOCH1ES Dako®). It began in the specimens of 1.8-2.5 cm of crown to rump length (CRL), from Days 25-29 (ovulation = Day 0), continued during gestation and intensified towards its end. The cholangiocytic differentiation was performed by the identification of cytokeratin 7 (CK7, Dako®). It was manifested at the final of gestation (specimens of 28.4 cm CRL, from Day 223 onwards). Parenchymal cells underwent a process of gradual differentiation (differentiation of hepatocytes preceded that of cholangiocytes). Cell proliferation was observed along gestation using the nuclear proliferation antigen (PCNA) and Ki-67. Hepatic organogenesis in the alpacas shares similar differentiation and proliferation mechanisms with other altricial, but phylogenetically distant, species.
Assuntos
Antígenos de Diferenciação/metabolismo , Camelídeos Americanos/embriologia , Diferenciação Celular , Proliferação de Células , Hepatócitos/metabolismo , Fígado/embriologia , Animais , Feminino , MasculinoRESUMO
N(omega)-nitro-L-arginine methyl ester (L-NAME) decreases the vasodilator effect of nitric oxide (NO) and induces pre-eclampsia in mouse. Sildenafil inhibits the degradation of nitric oxide and increases vasodilation. This study aimed to determine the effects of sildenafil citrate on angiogenesis and oxidative stress at the maternal foetal interface on pre-eclampsia-like mouse model induced by L-NAME. Twenty pregnant mice were divided into four groups: (i) vehicle control; (ii) L-NAME; (iii) sildenafil; (4) L-NAME+sildenafil. L-NAME was administered from day 7 of pregnancy and sildenafil from day 8 until day 16; animals were euthanized on day 17. Placental and foetal sizes and weights were measured; lipid peroxide levels and catalase activity in placental homogenates were determined, and placental vascular endothelia were identified by lectin-histochemistry using BSA-I lectin. Western blot analysis was used to determine VEGF expression in placental homogenates. No changes were seen in placental and foetal development in mice with normal pregnancies treated with sildenafil. Treatments with L-NAME reduced significantly the placental weight and average height and decreased the percentage of the endothelial surface. These alterations may be mediated by the reduction of NO levels in trophoblastic cells, due to the inhibitory effect of L-NAME on nitric oxide synthase (NOS) synthesis. This effect was offset by the treatment with sildenafil, with an increase in the percentage of the endothelial surface. In conclusion, our results indicate that treatment with sildenafil on pre-eclampsia mouse model can be used without adverse effects on the concept and its use in the treatment of pre-eclampsia is promising.
Assuntos
NG-Nitroarginina Metil Éster/administração & dosagem , Pré-Eclâmpsia/tratamento farmacológico , Citrato de Sildenafila/uso terapêutico , Vasodilatadores , Animais , Modelos Animais de Doenças , Feminino , Feto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Fisiológica/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Placenta/irrigação sanguínea , Placenta/efeitos dos fármacos , Pré-Eclâmpsia/induzido quimicamente , GravidezRESUMO
Bovine herpesvirus (BoHV) type 1.1 (BoHV-1.1) causes repeated outbreaks of upper respiratory disease and abortion in cattle. The systemic effects of BoHV-1.1 in rabbits, using intranasal inoculation are reported. Female rabbits were divided into four groups and inoculated with the virus 10 days before mating, and at 15 or 22 days of pregnancy. Studies of the clinical signs, antibody production, virus isolation, and DNA detection as well as histological and immunohistochemical studies were carried out on lungs, kidneys, spleen, placentas, uteri and foetal tissues. All virus-inoculated animals developed respiratory clinical signs and a humoral response. BoHV-1.1 was isolated from nasal swabs and plasma rich in leukocytes, and viral DNA was detected in blood, dead foetuses and placentas. Histopathological lesions were found in the respiratory tract and some placentas and foetuses were immunohistochemically positive. Intranasal inoculation might be useful to study the systemic effects of BoHV-1.1 infection in the rabbit model.
Assuntos
Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1 , Coelhos , Animais , Anticorpos Antivirais/sangue , Feminino , Infecções por Herpesviridae/virologia , Pulmão/patologia , Reação em Cadeia da Polimerase , Gravidez , Conchas Nasais/patologiaRESUMO
Mice are commonly used as an experimental model to investigate the Equid herpesvirus 1 (EHV-1) infection. This model easily reproduces the disease, and the clinical signs are more or less similar to those observed in the horse, the natural host. During natural infection, the acute course of respiratory infection is mandatory for the development of adaptive immune response. Since interactions between EHV-1 and anesthetics are possible, the study investigated whether the early events of murine pulmonary immune response could be affected by different anesthetics. Therefore, mice were experimentally infected with a unique EHV-1 strain under the effects of ether, ketamine/xylazine, or isoflurane. Clinical signs and histopathological lesions in the lungs were described, and the cell death and proliferation rates of sham-inoculated or infected animals were quantified using immunohistochemistry. Clinical signs were more severe in animals anesthetized with ether. Qualitative differences in the recruited inflammatory cells were observed following application of anesthesia. The level of infection between the infected groups was not statistically significant. However, lungs from ketamine/xylazine-anesthetized animals showed the highest cell death rates, whereas those from isoflurane-anesthetized animals showed the highest proliferation rates. It has been emphasized that anesthetics alone or their interactions with EHV-1 modify the response against the infection. An appropriate selection of the anesthetic during experimental studies is relevant to minimize wrong conclusions.
Assuntos
Anestésicos/farmacologia , Modelos Animais de Doenças , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/patologia , Herpesvirus Equídeo 1 , Pulmão/patologia , Análise de Variância , Animais , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Imuno-Histoquímica , Isoflurano , Ketamina , Pulmão/efeitos dos fármacos , Camundongos , XilazinaRESUMO
Vitamin D regulates mineral homeostases and enterocyte proliferation and differentiation. Hypervitaminosis D generates changes in cell proliferation, differentiation and apoptosis in several organs. We analysed morphometric parameters and proliferative and apoptotic indices in the intestinal epithelium of rabbits with hypervitaminosis D induced by the chronic treatment with the calcinogenic plant Solanum glaucophyllum. Rabbits were treated for 15 or 30 days. A group was treated for 15 days and led to possible recovery for 30 days. Another group was nutritionally restricted for 30 days. Morphological, morphometric, proliferative and apoptotic changes were found in the treated animals. Mild atrophy and reduced proliferation was found in the jejunum and ileum. Apoptosis increased in the crypts of the ileum and in the superficial epithelium and crypts of the rectum. Most of the alterations were partially recovered. The possible involvement in these changes of the hypervitaminosis D-like state induced by S. glaucophyllum is discussed.
Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Intestino Grosso/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Extratos Vegetais/toxicidade , Solanum glaucophyllum , Animais , Íleo/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Masculino , Folhas de Planta , CoelhosRESUMO
Vitamin D participates in mineral homeostasis, immunomodulation, cell growth and differentiation. The leaves of Solanum glaucophyllum contain high levels of 1,25-dihydroxyvitamin D3 as glycoside derivatives and their chronic ingestion generates a hypervitaminosis D-like state. We analyzed changes on carbohydrate expression as a cell differentiation indicator on samples of the small and large intestine of S. glaucophyllum-intoxicated rabbits, using conventional and lectin histochemistry. Male New Zealand white rabbits were intoxicated with S. glaucophyllum during two or four weeks and killed the day after. A group of animals ("possibly recovered group") were intoxicated during 15 days and killed at day 45 of the beginning of the experiment. We found changes in the lectin binding pattern in the small and large intestine of the intoxicated rabbits. Some of these changes were reverted in the possibly recovered group. Vitamin D could be a new regulator factor of the intestinal glycosylation process.
Assuntos
Calcitriol/toxicidade , Glicoconjugados/metabolismo , Intestinos/efeitos dos fármacos , Distúrbios Nutricionais/veterinária , Intoxicação por Plantas/veterinária , Coelhos , Solanum glaucophyllum , Animais , Glicoconjugados/química , Imuno-Histoquímica , Mucosa Intestinal/metabolismo , Intestinos/patologia , MasculinoRESUMO
Solanum bonariense intoxication is characterized by cerebellar neuronal vacuolation, degeneration, and necrosis. Cerebellar Purkinje cells seem especially susceptible, but more research is needed to determine the pathogenesis of neuronal necrosis and the mechanism of Purkinje cell susceptibility. Calbindin D28k (CbD28k) is highly expressed in Purkinje cells and has been used as a marker for normal and degenerative Purkinje cells. The goal of this study was to describe S bonariense-induced disease by ascertaining Purkinje cell-specific degenerative changes using CbD28k expression and to correlate this with apoptosis in Purkinje cells, as determined using TUNEL (transferase-mediated dUTP-biotin nick end-labeling) and ultrastructural changes. In all cases, an increase in both dose and duration of S bonariense intoxication resulted in a decrease in the number of Purkinje cells. CbD28k immunohistochemistry was an excellent marker for Purkinje cells because immunoreactivity did not change in normal or degenerative tissues. This finding suggests that excessive calcium excitatory stimulation does not induce rapid neuronal degeneration and death. As found in previous studies, TUNEL tests and electron microscopy suggest that Purkinje cell degeneration and death are not occurring via an apoptotic process. These findings suggest that S bonariense poisoning induces progressive Purkinje cell death that is not mediated by excitotoxicity or apoptotic activation.
Assuntos
Apoptose , Doenças dos Bovinos/metabolismo , Cerebelo/metabolismo , Intoxicação por Plantas/veterinária , Proteína G de Ligação ao Cálcio S100/metabolismo , Solanum/intoxicação , Animais , Calbindinas , Bovinos , Doenças dos Bovinos/patologia , Cerebelo/patologia , Feminino , Masculino , Intoxicação por Plantas/metabolismo , Intoxicação por Plantas/patologia , Células de Purkinje/metabolismo , Células de Purkinje/patologia , Alcaloides de Solanáceas/intoxicaçãoRESUMO
The intestinal epithelium has a critical roll in host defence. One specialised cell type involved in this function is the Paneth cell, which secretes many substances with antimicrobial properties in response to different stimuli. Under pathological conditions, changes in the Paneth cell number, morphology and location as well as in granule number, morphology and composition have been reported. In the normal animal, 1,25-dihydroxyvitamin D3 participates in the maintenance of mineral homeostasis, immunomodulation and cell proliferation and differentiation. Solanum glaucophyllum, a calcinogenic plant containing high levels of 1,25-dihydroxyvitamin D3, is responsible for a condition known as enzootic calcinosis in ruminants, characterised by loss of body condition and mineralization of soft tissues. Using and established rabbit model, this study analyses the changes that rabbit Paneth cells undergo during intoxication with S. glaucophyllum. Male New Zealand white rabbits were experimentally intoxicated with S. glaucophyllum for 15 or 30 days. Lectin, immunohistochemical and morphometric studies were carried out on Paneth cells from samples of jejunum. SBA, DBA and WGA lectins bound to Paneth cells-granules in both normal and intoxicated rabbits, with more heterogenity in the labelling of granules from intoxicated rabbits. Paneth cells in both groups were immunonegative for lysosyme. A time and dose-dependent increase in the size and number of Paneth cells was found in both intoxicated groups. We suggest that the changes described in these cells may be directly or indirectly induced by S. glaucophyllum intoxication.