Endogenous neuregulin-1 expression in the anterior pituitary of female Wistar-Furth rats during the estrous cycle / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes in endogenous neuregulin-1 (Nrg1) expression in the anterior pituitary of female Wistar-Furth rats in different phases of the estrous cycle.</p><p><b>METHODS</b>Female Wistar-Furth rats during estrous cycles were used. RT-PCR was employed to study the changes in the expression of Nrg1 isoforms and their cognate receptors ErbB-2 and ErbB-4 in the anterior pituitary in different phases of the estrous cycle. Western blotting was used to detect Nrg1 expression at the protein level. Immunofluorescence staining was used to identify hypophyseal cells expressing Nrg1 and observe the localization and distribution of Nrg1 and functional phosphorylation of ErbB-4. The co-expression of Nrg1 and ErbB-4 in the anterior pituitary of Rhesus monkey was also investigated.</p><p><b>RESULTS</b>Some of the Nrg1 isoforms, especially type III Nrg1s, were expressed at a higher level during the estrous cycle I (E1) and estrous cycle II (E2), a result consistent with that of Western blotting for samples of the anterior pituitaries collected at these phases. Immunofluorescence staining identified the gonadotrophs as the main source of Nrg1, and showed an extensive distribution of Nrg1 in the anterior pituitary in E1 and E2 phases accompanied by apparent phosphorylated activation of ErbB-4. Adjacent distribution of Nrg1- and ErbB-4-positive cells was also observed in the anterior pituitary of male Rhesus monkeys.</p><p><b>CONCLUSION</b>Our results provide evidence for the expression of multiple Nrg1 isoforms and the presence of Nrg1/ErbB-4 signaling in the anterior pituitary of female Wistar-Furth rats. This signaling demonstrates an estrous cycle phase-related pattern. Additionally, Nrg1/ErbB-4-based juxtacrine signaling may exist in the anterior pituitary of male non-human primate.</p>

Allograft tolerance induced by FasL chimeric protein decorated donor splenocytes / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of strategy of allograft tolerance induction by injection of FasL-decorated donor splenocytes.</p><p><b>METHODS</b>Chimeric FasL with core streptavidin (SA-FasL) was efficiently displayed on the surface of splenocytes by the technology of ProtEx™. Heterotopic heart transplant procedures were performed from donor WF rats to recipient ACI rats, F344 rats were used as third-party. Intraperitoneal injection of ACI rats with "decorated" WF splenocytes was used as the approach to induce tolerance in this study. According to different therapeutic strategies, three groups were set up: SA-FasL group (n = 23), SA group (n = 20) and naive splenocytes only group (n = 8). No treatment group was regarded as control (n = 10). Adoptive transfer was underwent with injection of splenocytes from tolerant recipients into naive ACI followed by heart transplant procedures. Mixed lymphocyte reaction (MLR) and third party transplantation were performed to detect allogenic tolerance.</p><p><b>RESULTS</b>The injection of ACI rats with WF rat splenocytes displaying SA-FasL on their surface resulted in tolerance to donor, but not F344 third-party cardiac allografts. There were 70% cardiac allografts in SA-FasL group achieved long term survival, and it was significantly higher than the rats in other groups (P < 0.05). Adoptive transfer of splenocytes from long-term graft recipients into naive unmanipulated ACI rats resulted in indefinite survival of secondary WF grafts. Donor specific tolerance was identified by MLR and third-party transplant.</p><p><b>CONCLUSION</b>The direct display of SA-FasL on the cell membrane in a rapid and efficient manner provides a practical and clinically applicable means of immunomodulation for tolerance induction with considerable therapeutic potential for transplantation.</p>

FTY720-induced lymphocyte apoptosis inhibits acute graft versus host disease in rat small bowel transplantation / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect and mechanism of FTY720 on acute graft versus host disease (GVHD) in rat small bowel transplantation (SBTx).</p><p><b>METHODS</b>Heterotopic SBTx was performed using a parent (WF)-into-F1 (WFxACI) rat combination. Recipient rats were divided into experimental group (n=6) and control group (n=6). Rats in the experimental group were administered with FTY720 at 0.5 mg/kg for 14 days. Lymphocyte apoptosis in the liver and the mucosa of intestine and graft was detected by TUNEL and flow cytometry 15 days after transplantation. Recipient survival and lymphocyte apoptosis were compared between the two groups.</p><p><b>RESULTS</b>Recipients in the control group died of GVHD after a mean survival time of (16+/-2.1) days. FTY720-treated recipients had a significantly longer survival (>100 days). After administration of FTY720, the percentage of apoptotic lymphocytes was significantly increased in the graft as compared to that in the control group by flow cytometry. The ratio of apoptotic lymphocyte in the liver and graft was also significantly higher in the experimental group by TUNEL.</p><p><b>CONCLUSION</b>FTY720 effectively induces the lymphocyte apoptosis, inhibits the lesion of target tissues by GVHD, and prolongs the recipient survival.</p>

National equipment of intraoperatory gamma detection in the identification of sentinel lymph node in animal model / Equipamento nacional de detecção gama intra-operatória na identificação de linfonodo sentinela

PURPOSE: To investigate a national equipment of intraoperatory gamma detection in the identification of sentinel lymph node. METHODS: Thirty young adult male rats were used. After anesthetized, animals were divided into two groups of 15 animals each. Animals from group A received dextram 500 - Tc99 radiopharmaceutical and patent blue V and those from group B received only patent blue V to map the lymphatic drainage. The presence of radiation in the background area, in the area of injection and of the ex vivo sentinel lymph node of group A were measured. After the exeresis, each lymph node in group A and in group B was mixed forming a new random sequence and the radioactive reading of each lymph node was carried out, using both pieces of equipment. RESULTS: The hottest sentinel lymph node was identified by the national equipment when radiation was measured in the area of limphatic drainage after the Dextran 500 was injected. Also, the ex vivo sentinel lymph node. The national equipment has also detected radiation in the lymph nodes that had not received radiopharmaceutical, leading to false positive, checked by the application of Mann-Whitney tests and Student's paired t-tests. The Cronbach alpha has shown high internal consistency of data 0,9416. CONCLUSIONS: The national equipment of intraoperatory gamma detection identifies the LS and showed false positives LS and needs improvement.

OBJETIVO: Investigar o equipamento nacional de detecção gama intra-operatória na identificação de linfonodo sentinela. MÉTODOS: Foram utilizados 30 ratos machos, adultos jovens. Depois de anestesiados, os animais foram distribuidos em dois grupos de 15 animais cada. O grupo A recebeu radiofármaco dextran 500 - Tc99 e azul patente V e o grupo B, somente azul patente V para realização do mapeamento linfático. Foi realizada a medição da captação radioativa da região de fundo, do sítio de injeção e do linfonodo sentinela ex vivo do grupo A. Após a exérese, cada linfonodo do grupo A e do grupo B foram misturados formando uma nova seqüência aleatória e procedeu a leitura da radioatividade de cada linfonodo com os dois equipamentos. RESULTADOS: O linfonodo sentinela hipercaptante foi identificado pelo equipamento nacional durante as medições da captação radioativa na região do sítio de injeção e linfonodo sentinela ex vivo. O equipamento nacional detectou radiação mesmo nos linfonodos que não receberam o radiofármaco, causando falso positivo, verificado na aplicação dos testes de Mann-Whitney e t pareado de Student. O alfa de Cronbach mostrou alta consistência interna dos dados (0,9416). CONCLUSÕES: O equipamento nacional de detecção gama intra-operatória identifica o linfonodo sentinela e mostra falsos positivos e necessita de aprimoramento.

Comparação entre os bioenxertos de hidroxiapatita de cálcio e submucosa de intestino delgado porcino no preenchimento de defeitos ósseos criados em mandíbula de ratos / Defect repair in rat mandible with hydroxyapatite cement comparad to small intestine submucosa

OBJETIVO: O objetivo do presente estudo consiste em avaliar a regeneração óssea em defeito criado na mandíbula de ratos utilizando dois bioenxertos: hidroxiapatita de cálcio sintética e submucosa de intestino delgado porcina. FORMA DE ESTUDO: Experimental randomizado. MATERIAL E MÉTODO: Foram utilizados 24 ratos da linhagem Wisthar-Furth. Um defeito ósseo de 0,75cm x 1,5cm no corpo de cada hemimandíbula foi realizado em todos os animais com broca esférica de baixa rotação. Padronizou-se à esquerda o preenchimento do defeito ósseo, no grupo I com 15 microgramas de hidroxiapatita e no grupo II com preenchimento de submucosa de intestino delgado porcina (SID), e à direita o não-preenchimento serviu como controle. A eutanásia foi realizada no 40° dia de pós-operatório, após a qual se procederam as análises macroscópicas e histológicas das peças. RESULTADOS: O comprimento médio em milímetros das hemimandíbulas do grupo hidroxiapatita foi de 3,75, e o do grupo SID 3,03 e o do grupo controle foi de 2,63 (p: 0,0022). No grupo hidroxiapatita a neoformação óssea perfez uma área correspondente à 76,64 por cento do total já no grupo SID 63,64 por cento do total. CONCLUSÃO: Os resultados macroscópios e microscópicos foram superiores com a utilização do enxerto de hidroxiapatita quando comparado ao grupo submucosa de intestino delgado porcino. Entretanto os dois bioenxertos mostraram-se osteoindutores quando comparados ao controle.

In vivo Recombinant Adenovirus-mediated p53 Gene Therapy in a Syngeneic Rat Model for Colorectal Cancer

The p53 gene has a significant role in controlling genomic stability of cancer. The purpose of this study was to evaluate the tumor response of allograft colorectal tumor treated with Ad5CMV-p53 in a syngeneic rat model. Two weeks after the inoculation of WB-2054-M5 tumor cells in the flank of rats, rats were randomly assigned by tumor size to one of three groups (n=18 in each): phosphate buffered saline (PBS), Ad5CMV, and Ad5CMV-p53. Recombinant adenovirus or PBS was administered through intratumoral injection at three divided doses every other day for 4 weeks. Apoptosis of the tumors was evaluated using TUNEL assay. After 2 and 4 weeks of treatment, the volume (cm3) of tumors in PBS, Ad5CMV, and Ad5CMV-p53 was as follows: 2 week: 1.66 +/-0.43, 1.40 +/-0.47, 0.75 +/-0.26 (p<0.001), 4 week: 4.41 +/-0.88, 3.93 +/-1.86, 2.33 +/-0.51 (p<0.001). Tumor growth showed no statistically significant difference between the PBS and Ad5CMV groups (6-week vol. p=0.32). The TUNEL assay results revealed more apparent apoptotic cells in Ad5CMV-p53-treated tumors than in other groups. Growth of allograft colorectal cancer in the syngeneic rat model was significantly suppressed by intratumoral Ad5CMV-p53 gene therapy. These results demonstrate that gene replacement therapy with p53 may provide a novel modality of treatment in conjunction with other present treatments for metastatic colorectal cancer.

Effects of caffeine on learning and memory in rats tested in the Morris water maze

We studied some of the characteristics of the improving effect of the non-specific adenosine receptor antagonist, caffeine, using an animal model of learning and memory. Groups of 12 adult male Wistar rats receiving caffeine (0.3-30 mg/kg, ip, in 0.1 ml/100 g body weight) administered 30 min before training, immediately after training, or 30 min before the test session were tested in the spatial version of the Morris water maze task. Post-training administration of caffeine improved memory retention at the doses of 0.3-10 mg/kg (the rats swam up to 600 cm less to find the platform in the test session, P<=0.05) but not at the dose of 30 mg/kg. Pre-test caffeine administration also caused a small increase in memory retrieval (the escape path of the rats was up to 500 cm shorter, P<=0.05). In contrast, pre-training caffeine administration did not alter the performance of the animals either in the training or in the test session. These data provide evidence that caffeine improves memory retention but not memory acquisition, explaining some discrepancies among reports in the literature

Avaliaçäo da resposta terapêutica aos análogos da somatostatina em uma linhagem de tumores hipofisários somato-mamotróficos transplantáveis do rato

Foram avaliados os efeitos de um análogo da somatostanina, a octreotida, sobre a secreção hormonal e a proliferação celular de tumores hipofisários do rato, secretores de PRL (SMtTW2) ou GH e PRL (SMtTW10), considerados como modelos experimentais de adenomas mamo-somatotróficos. Os tumores primários foram espontâneos, e transplantados sob a cápsula renal de ratos Wistas-Furth-Ico. Os ratos transplantados com os tumores SMtTW2, secretaram apenas PRL. Os animais transplantados com os tumores SMtTW10 apresentaram, no quarto mês do experimento, níveis de GH e de PRL, superiores a 5000 ug/l e 200 ug/l, respectivamente. Neste período, os ratos receberam uma única injeção subcutânea de Octreotida 100 ug/kg e os níveis plasmáticos de GH e de PRL foram determinados após 60 minutos. Visando avaliar os efeitos do tratamento crônico com octreotida, sobre a secreção hormonal e o crescimento tumoral, os animais foram distribuídos em grupos pareados para a idade, que receberam diferentes regimes de tratamento, por um período de três meses[...] Em conclusão, os tumores mamo-somatotróficos SMtTW10 expressam receptores funcionais, que permitem os efeitos agudos da Octreotida sobre a secreção hormonal. A ausência destes efeitos, na vigência de um tratamento crônico, deve-se provavelmente, a um processo de dessensibilização que poderia ocorrer em qualquer etapa da via de sinalização intra-celular, ou os receptores para a somatostatina expressos nos tumores, não apresentam sensibilidade adequada à octreotida

Rat allotransplantation of epigastric microsurgical flaps: a study of rejection and the immunosuppressive effect of cyclosporin A

The rejection of allotransplantation of epigastric microsurgical flaps and the effect of immunosuppression have been studied in 58 rats. Three sets of experiments were planned: (1) Wistar Furth isogenic donors and receptors (control set); (2) Brown Norway donors and Wistar Furth receptors (rejection set); and (3) Brown Norway donors and Wistar Furth immunosuppressed receptors (cyclosporin A set). Cyclosporin A (10 mg/kg/d) treated rats had a transplantation survival rate of up to 30 days: 83.3 percent among isogenic animals and 60 percent among allogeneic. There was 100 percent rejection by the 9th day after the transplantation in allogeneic non-immunosuppressed rats. Biopsies embedded with historesin were taken from the flap and normal contralateral skin (used as control) on the 3rd, 7th, 15th, and 30th days after the surgery. A quantitative study of infiltrating lymphocytes in the flaps, with and without cyclosporin A, was done by evaluating the local inflammatory infiltrate. A significant increase in the number of lymphocytes among the rejection and immunosuppressed groups was seen, as compared to the isogenic set. Local lymphocytosis in allogeneic non-immunosuppressed transplantations reached its highest level on the 3rd day after surgery, before gross findings of rejection, which could only be seen by naked eye on the 5th or 6th day. Therefore, we conclude that cyclosporin A is effective in preserving allogenic transplantation in rats. Biopsies of transplanted areas may contribute to earlier diagnosis of the need for immunosuppressive therapy.

Effects of oncostatin M on hormone release of rat pituitary cells in primary culture

It has become increasingly clear that cytokines play an important role in modulating neuroendocrine regulation, especially in the secretion of corticotropin (ACTH) in the pituitary. Oncostatin M (OSM), a cytokine of IL-6 family has been reported to increase ACTH secretion and pro-opiomelanocortin (POMC) transcription in murine corticotroph pituitary tumor cells (AtT20 cells). The present study was undertaken to determine the effects of OSM on hormonal release in primary culture of rat pituitary cells. Growth hormone or prolactin release was not affected by OSM. OSM (1 nM) stimulated ACTH release (35.1% increase versus control, p>0.001) in dispersed pituitary cells of rat to a lesser extent than in AtT20 cells. Corticotropin releasing hormone (CRH) (10 nM) also induced a 2.3-fold increase of ACTH secretion (p>0.001), but co-treatment of OSM and CRH did not exhibit any synergistic effect on ACTH secretion. We conclude OSM has a stimulatory effect on ACTH secretion in normal rat pituitary cell cultures, and OSM acts mainly on corticotroph, supporting the potential role of OSM to modulate immune-endocrine regulation in the pituitary.

Effects of oncostatin M on hormone release of rat pituitary cells in primary culture

It has become increasingly clear that cytokines play an important role in modulating neuroendocrine regulation, especially in the secretion of corticotropin (ACTH) in the pituitary. Oncostatin M (OSM), a cytokine of IL-6 family has been reported to increase ACTH secretion and pro-opiomelanocortin (POMC) transcription in murine corticotroph pituitary tumor cells (AtT20 cells). The present study was undertaken to determine the effects of OSM on hormonal release in primary culture of rat pituitary cells. Growth hormone or prolactin release was not affected by OSM. OSM (1 nM) stimulated ACTH release (35.1% increase versus control, p>0.001) in dispersed pituitary cells of rat to a lesser extent than in AtT20 cells. Corticotropin releasing hormone (CRH) (10 nM) also induced a 2.3-fold increase of ACTH secretion (p>0.001), but co-treatment of OSM and CRH did not exhibit any synergistic effect on ACTH secretion. We conclude OSM has a stimulatory effect on ACTH secretion in normal rat pituitary cell cultures, and OSM acts mainly on corticotroph, supporting the potential role of OSM to modulate immune-endocrine regulation in the pituitary.

Lung tissue mechanics in the early stages of induced paracoccidioidomycosis in rats

Pulmonary dysfunction represents the most important cause of death in patients with paracoccidioidomycosis (PBM). In order to investigate the functional changes of the lungs in the early stages of PBM, a model of benign disease was developed by intratracheal challenge of 12-week old isogenic Wistar rats with 1 x 10(6) yeast forms of Paracoccidioides brasiliensis. Animals were studied 30 and 60 days after infection, when fully developed granulomas were demonstrable in the lungs. Measurements of airway reistance, lung elastance and tissue hysteresis were made during sinusoidal deformations (100 breaths/min, tidal volume = 2 ml) with direct measurement of alveolar pressure using the alveolar capsule technique. Infection caused a significant increase in hysteresis (infected: 1.69, N = 13; control: 1.13, N=12,P = 0.024, ANOVA), with no alterations in airway resitance or lung elastance. Histopathological analysis revealed the presence of fully developed granulomas located in the axial compartment of the lung interstitial space. These results suggest that alterations of tissue mechanics represent an early event in experimental PBM.

Uso de retalho axial de parede abdominal para crescimento de neomucosa do intestino delgado: estudo experimental em ratos / Use of abdominal wall axial flaps to grow samll bowel neomucosa: experimental stydu in rats

O crescimento de uma nova mucosa de remanescentes do intestino delgado em pacientes com síndrome de intestino curto pode oferecer uma estratégia para o tratamento deste grave problema clínico. Realizamos um estudo experimental em 15 ratos Wistar, confeccionando um retalho axial da parede abdominal baseado na artéria epigástrica cranial e suturando sobre a superfície peritoneal um segmento aberto de íleo terminal. Os animais foram sacrificados com 7, 14 e 30 dias após o experimento. O exame macroscópico demonstrou um crescimento progressivo da neomucosa sobre a base serosa do retalho. O estudo histológico confirmou a presença de mucosa essencialmente normal com vilosidades maduras e bem desenvolvidas atapetando o retalho. Concluímos que a neomucosa pode crescer no retalho axial da parede abdominal e é similar à mucosa do intestino delgado pelo exame histológico

Immunomodulatory effect of cimetidine on the proliferative responses of splenocytes from T. cruzi-infected rats

O efeito imunomodulatorio da Cimetidine (CIM), um antagonista do receptor de histamina-tipo 2, foi avaliado na resposta blastogenica a Con A em celulas de ratos Wistar Furth (WF) infectados pela cepa Y de Trypanosoma cruzi (T.cruzi). Foi observado que apenas na concentracao de "10 POT. -3"M de Cimetidine houve amplificacao da resposta blastogenica de esplenocitos normais a Con A. Entretanto, a capacidade mitogenica de esplenocitos de animais infectados foi restaurada na presenca de molaridades da droga que variaram entre "10 POT. -8" a "10 POT. -3". Os resultados demonstraram que a CIM tem o potencial de modular a resposta mitogenica de celulas de animais infectados pelo T.cruzi, sugerindo um papel imunoregulatorio da histamina e/ou celulas que expressam receptores H2 nesta infeccao.