RESUMO
The liver plays essential roles in human and animal organisms, such as the storage, release, metabolism, and elimination of various endogenous or exogenous substances. Although its vital importance, few treatments are yet available when a hepatic failure occurs, and hence, the use of stem cells has arisen as a possible solution for both human and veterinary medicines. Previous studies have shown the existence of hepatic progenitor cells in human fetuses that were positive for EpCAM and NCAM. There is limited evidence, however, further identification and characterization of these cells in other species. Considering the similarity between dogs and humans regarding physiology, and also the increasing importance of developing new treatments for both veterinary and translational medicine, this study attempted to identify hepatic progenitor cells in canine fetal liver. For that, livers from canine fetuses were collected, cells were isolated by enzymatic digestion and cultured. Cells were characterized regarding morphology and expression of EpCAM, NCAM, Nestin, and Thy-1/CD90 markers. Our results suggest that it is possible to identify hepatic progenitor cells in the canine fetal liver; however, for therapeutic use, further techniques for cellular isolation and culture are necessary to obtain enriched populations of hepatic progenitors from the canine fetal liver.
Assuntos
Cães/embriologia , Células-Tronco Fetais/citologia , Fígado/embriologia , Animais , Biomarcadores/metabolismo , Células Cultivadas , Cães/anatomia & histologia , Molécula de Adesão da Célula Epitelial/metabolismo , Células-Tronco Fetais/metabolismo , Feto/citologia , Feto/embriologia , Hepatócitos/metabolismo , Fígado/citologia , Fígado/metabolismo , Antígenos Thy-1/metabolismoRESUMO
The aim of this study was to evaluate the effect of epidural bupivacaine administration at the first lumbar vertebra on cardiopulmonary variables, arterial blood gases and anti-nociception. Sixteen healthy female dogs were randomly assigned into two groups based on bupivacaine dose: G1 group, 1mg kg-1 or G2 group, 2mg kg-1, diluted in the same final volume (1mL4kg-1). Cardiopulmonary variables were measured and arterial blood gas was collected (T0), it was repeated 10 minutes after intravenous administration of butorphanol 0.4mg kg -1 (T1). Anesthesia was induced with intravenous etomidate at 2mg kg-1 and the epidural catheter was introduced and placed at the first lumbar vertebra. Thirty minutes later, bupivacaine was administered epidurally. Cardiopulmonary measurements and arterial blood gas analysis were recorded at 10 minute intervals (T2 to T6). Evaluation of pre surgical anti-nociception was performed at 5 minute intervals for 30 minutes by clamping the hind limbs, anus, vulva, and tail with the dogs awake. Subsequently, ovariohysterectomy was performed and adequacy of surgical anti-nociception was evaluated at 5 time points. Parametric data were analyzed using the F test with a <0.05 significance. After bupivacaine administration, there were differences between groups just for bicarbonate means (HCO3-) on T6 (P=0.0198), with 18.7±1.3 and 20.4±0.8 for G1 and G2, respectively. After T1, before bupivacaine administration, both groups presented a slightly lower pH, base excess (BE), the end-tidal carbon dioxide tension (PECO2), and partial pressure of carbon dioxide (PaCO2), suggesting mild metabolic acidosis. G2 showed better antinociceptive effect both before and during surgery. It was possible to perform ovariohysterectomy in 87.5% of the G2 bitches and 25% of the G1 bitches. The two doses of bupivacaine evaluated do not cause important alterations in the studied parameters and the dose of 2mg kg-1 results in a better antinociceptive effect.(AU)
O objetivo deste estudo foi avaliar os efeitos da administração epidural de bupivacaína à altura da primeira vértebra lombar sobre variáveis cardiopulmonares, hemogasometria arterial e antinocicepção. Dezesseis cadelas foram separadas aleatoriamente em dois grupos que se diferenciaram pela dose de bupivacaína, 1mg/kg (G1) ou 2mg/kg (G2), diluídas no mesmo volume final (1mL/4kg). As variáveis cardiopulmonares e hemogasometria arterial foram coletadas antes (T0) e após 10 minutos da administração intravenosa de 0,4mg/kg de butorfanol (T1). A anestesia foi induzida com 2mg/kg de etomidato intravenoso para introdução do cateter epidural. Após 30 minutos, a bupivacaína foi administrada e, passados 10 minutos, nova coleta de parâmetros foi feita, sendo repetida a cada 10 minutos (T2 a T6). Após cinco minutos da administração de bupivacaína, iniciou-se a avaliação da antinocicepção pré-cirúrgica, repetida a cada cinco minutos durante 30 minutos. Então, iniciou-se a cirurgia de ovário-histerectomia, na qual se avaliou a antinocicepção transcirúrgica em cinco momentos. Os resultados paramétricos foram analisados pelo software SAS 9.4 (2010), utilizando-se o teste F com significância menor que 0,05. Houve diferença entre as médias dos grupos após administração de bupivacaína apenas para bicarbonato em T6 (P=0.0198), sendo 18,7±1,3 e 20,4±0,8 as médias do G1 e G2, respectivamente. Desde T1, os grupos apresentaram valores de pH, excesso de bases, pressão parcial de gás carbônico no sangue arterial e tensão de dióxido de carbono ao final da expiração pouco abaixo do fisiológico, sugerindo acidose metabólica discreta. O G2 apresentou efeito antinociceptivo pré e transcirúrgico superior ao G1. Foi possível realizar a cirurgia em 87,5% das cadelas do G2 e em 25% das cadelas do G1. Concluiu-se que as duas doses de bupivacaína avaliadas não acarretam alterações importantes nos parâmetros fisiológicos estudados e a dose de 2mg/kg determina melhor efeito antinociceptivo que a dose de 1mg/kg.(AU)