Electro-acupuncture-induced neuroprotection is associated with activation of the IGF-1/PI3K/Akt pathway following adjacent dorsal root ganglionectomies in rats.

The aim of the present study was to investigate the putative role and underlying mechanisms of insulin­like growth factor 1 (IGF­1) in mediating neuroplasticity in rats subjected to partial dorsal root ganglionectomies following electro­acupuncture (EA) treatment. The rats underwent bilateral removal of the L1­L4 and L6 dorsal root ganglia (DRG), sparing the L5 DRG, and were subsequently subjected to 28 days of EA treatment at two paired acupoints, zusanli (ST 36)­xuanzhong (GB 39) and futu (ST 32)­sanyinjiao (SP 6), as the EA Model group. Rats that received partial dorsal root ganglionectomies without EA treatment served as a control (Model group). Subsequently, herpes simplex virus (HSV)­IGF­1, HSV­small interfering (si) RNA­IGF­1 and the associated control vectors were injected into the L5 DRG of rats in the EA Model group. HSV­IGF­1 transfection enhanced EA­induced neuroplasticity, which manifested as partial recovery in locomotor function, remission hyperpathia, growth of DRG­derived spared fibers, increased expression of phosphorylated (p­) phosphatidylinositol 3­kinase (PI3K) and Akt, and increased pPI3K/PI3K and pAkt/Akt expression ratios. By contrast, HSV­siRNA­IGF­1 treatment attenuated these effects induced by HSV­IGF­1 transfection. The results additionally demonstrated that HSV­IGF­1 transfection augmented the outgrowth of neurites in cultured DRG neurons, and interference of the expression of IGF­1 retarded neurite outgrowth. Co­treatment with a PI3K inhibitor or Akt siRNA inhibited the aforementioned effects induced by the overexpression of IGF­1. In conclusion, the results of the present study demonstrated the crucial roles of IGF­1 in EA­induced neuroplasticity following adjacent dorsal root ganglionectomies in rats via the PI3K/Akt signaling pathway.

Establishing a successful rat model of duodenal- jejunal bypass: A detailed guide.

Gastric bypass surgery, an operation that restricts the stomach and bypasses the duodenum and part of the jejunum, results in major improvement or remission of type 2 diabetes. Duodenual-jejunal bypass was developed by one of the authors (FR) as an experimental, stomach-sparing variant of gastric bypass surgery to investigate weight-independent mechanisms of surgical control of diabetes. Duodenual-jejunal bypass has been shown to improve various aspects of glucose homeostasis in rodents and in humans, thus providing an experimental model for investigating mechanisms of action of surgery and elusive aspects of gastrointestinal physiology. Performing duodenual-jejunal bypass in rodents, however, is associated with a steep learning curve. Here we report our experience with duodenual-jejunal bypass and provide practical tips for successful surgery in rats. Duodenual-jejunal bypass was performed on 50 lean rats as part of a study aimed at investigating the effect of the procedure on the physiologic mechanisms of glucose homeostasis. During the study, we have progressively refined details of anatomic exposure, technical aspects of duodeno-jejunostomy and peri-operative care. We analysed the role of such refinements in improving operative time and post-operative mortality. We found that refinement of exposure methods of the gastro-duodenal junction aimed at minimizing tension on small visceral vasculature, technical aspects of duodeno-jejunal anastomosis and peri-operative management played a major role in improving the survival rate and operative time. Overall, an experimental model of duodenual-jejunal bypass was successfully reproduced. Based on this experience, we describe here what we believe are the most important technical tips to reduce the learning curve for the procedure.

Emprego de Túnica albugínea heteróloga ovina como reforço de parede abdominal em ratos / Employment of ovine heterologous Tunic albuginea as abdominal wall reinforcement in rats

Hérnias são umas das afecções que mais acometem os pequenos e grandes animais, podendo ter origem traumática ou não. Estas afecções, geralmente, necessitam de um reparo cirúrgico o mais rápido possível, devido ao fato de suas consequências poderem levar o animal ao óbito. Alguns estudos têm avaliado o comportamento da túnica albugínea como biomaterial de enxertia para reforço de parede abdominal, obtendo resultados favoráveis. O presente trabalho tem como objetivo avaliar o comportamento do enxerto de túnica albugínea ovina na parede abdominal de ratos. Foram selecionados 30 ratos da raça Wistar, os quais foram divididos em 2 grupos de 15 animais, sendo um grupo controle (C), um grupo teste (TA), onde os animais receberam reforço de parede abdominal com túnica albugínea ovina. Cada grupo foi dividido em três subgrupos contendo cinco animais, que foram submetidos à eutanásia nos dias 7, 21 e 42. O material coletado foi submetido a análises macroscópicas e histopatológicas a fim de afirmar a aplicabilidade do material e propor a utilização da túnica albugínea heteróloga como material de enxertia para a reconstrução da parede abdominal. Nos animais do grupo TA observou-se maior infiltrado inflamatório, neovascularização, deposição de colágeno e fibrose do que nos animais do grupo controle, concluindo assim que a túnica albugínea ovina é um biomaterial que funciona como substrato e promove uma precocidade da cicatrização de parede abdominal de ratos.

Hernias are one of the infections that most affect small and large animals, and may have traumatic origin or not. These conditions usually require a surgical repair as soon as possible, due to the fact that its consequences can lead the animal to death. Some studies have evaluated the behavior of the Tunica albuginea as a biomaterial for grafting abdominal wall reinforcement, obtaining favorable results. This study aims to evaluate the ovine Tunica albuginea graft behavior in the abdominal wall of rats. We selected 30 Wistar rats, which were divided into 2 groups of 15 rats, with a control group (C) and a test group (TA) where the rats received abdominal wall reinforcement with ovine Tunica albuginea. Each group was divided into three subgroups with five rats that were sacrificed on days 7, 21 and 42. The collected material was submitted to macroscopic and histopathological analysis to affirm the suitability of the material and propose the use of heterologous Tunica albuginea as grafting material for the reconstruction of the abdominal wall. In the TA group there was a higher inflammatory infiltration, neovascularization and collagen deposition and fibrosis than in group control, thus concluding that the ovine Tunica albuginea is a biomaterial that acts as substrate and promotes precocity of the abdominal wall healing of rats.

Surgery and electrochemotherapy treatment of incompletely excised mammary carcinoma in two male pet rats (Rattus norvegicus).

Two male rats (Rattus norvegicus; 18 and 24 months old), were referred for treatment of large masses located in the axillary area. Following total body radiography and hematological and serum biochemical analysis, the rats were anesthetized, and the masses were surgically removed. Both lesions were diagnosed as mammary carcinoma based on histopathological diagnosis. The tumor beds were treated with two sessions of electrochemotherapy (ECT), two weeks apart. ECT involved cisplatin administration in the tumor bed, followed by a series of eight biphasic electric pulses. The treatment was well tolerated, and the rats were disease-free after 10 and 14 months. Therefore, adjuvant ECT resulted in good local control of mammary carcinoma and can potentially be used for adjuvant treatment of pet rats with cutaneous and adnexal tumors.

Surgical Skills Training with Cryopreserved Rat Stomachs.

The objective of this study is to present a high-fidelity bench model of cryopreserved stomachs that can be used while learning surgical skills. Thirty stomachs were harvested from Wistar rats at the end of non-abdominal research studies. The stomachs were washed with cold saline solution and filled with hyaluronic acid solution. The organs were then placed into cryovials and cryopreserved at -30 °C for 60 days. The stomachs were thawed to room temperature on the day of the surgical skills practice and two full-thickness incisions were made. Reporting on their experiences, 22 participants (73.33%) felt that the cryopreserved stomach was identical to in vivo rat stomachs, 24 (80.00%) reported that the stomach was easy to handle, and 27 (90%) reported the tissue was non-friable. Moreover, 29 participants (96.6%) finished the suturing without tears and 100% recommended it as a biomaterial for surgical training. The cryopreserved stomach is a practical, reproducible, low-cost, and high-fidelity bench model that allows surgical fellows to learn how to handle a stomach and improve their surgical abilities before performing surgery on patients or laboratory animals.

Evaluation of the sufficiency of pedicled temporoparietal fascial flap on rat head and neck defects: detailed anatomical study.

The temporoparietal flap containing the temporal fascia has a wide spectrum of applications in head and neck surgery. The aim of this study is to demonstrate a temporoparietal fascial flap model that can be used in various head and neck defects in rats. Ten male Sprague-Dawley rats weighing 250-300 g were used in this study. Temporoparietal fascial flaps were elevated with the axial pedicle from the rats using microsurgical techniques. The arc rotations of the flaps on the pedicles were examined and the dimensions of the defects these flaps could cover were identified. The flaps were observed to be the right size for use with defects of the occipital, temporal and mastoid regions, ear, facial nerve and the mandible. The temporoparietal fascial flap is an experimental flap model, which can be useful in experimental studies related to complex head and neck defects.

Assisted ventilation without endotracheal intubation in rats.

This technique was performed to allow for an additional approach to assist in ventilation. A modified ventilation nose cone was placed over the nose, which allowed the animal to not require endotracheal intubation. This method was effective in ventilating the animals during thoracic and abdominal procedures without requiring endotracheal intubation.

A new model for repair of the Achilles tendon in the rat.

The Sprague-Dawley rat is an excellent model for studies of Achilles tendon repair. Most researchers use a modification of the Kessler technique for suture repair of the Achilles tendon in rats. While this technique provides adequate strength, early mobilization is not recommended. Prior to healing, the load will be borne completely by the suture repair, subjecting it to rupture. To prevent this complication, investigators employing the Kessler repair often immobilize the operative extremity with a cast or splint. This has also been shown to be detrimental to the peak load borne by the tendons prior to rupture. A double-loop locking technique of suture repair for rat Achilles tendons is favored over the modified Kessler technique. As force is applied across the repair, the suture pulls on the tendon, sharing the load. This allows for early mobilization of repaired tendons, with minimal risk of rupture. Additionally, no immobilization is required for the operative extremity. One hundred repairs have been performed using this double-loop locking technique. All animals have been able to mobilize with minimal limp immediately after recovering from anesthesia, and there have been no ruptures. No other complications have occurred (hematoma, seroma, infection, dehiscence). This technique of tendon repair is ideal for use in studies of tendon repair in the rat, since it is easy to perform and eliminates the need for immobilization of the operative leg.

Accidental renal injury by an external heating device during surgery in rats.

Hypothermia can be caused by anaesthesia and/or surgery and represents a daily challenge in the operating room. Experimental animal surgery settings typically use heating pads or warming blankets to maintain the rodent's body temperature during long-lasting experiments. Warming is crucial in small animal experiments because these animals quickly lose temperature due to their large body surface to body weight ratio. While establishing a left ventricular infarction model in rats, we inserted a rectal temperature probe. The heating pad's set point was 37°C. Although a dual set point control circuit should prevent overheating, we observed a maximum heating pad's surface temperature of 43°C between the animal's back and the surface of the heating pad. At the end of the experiments, which lasted up to 8 h, the animals showed severe haematuria and segmental kidney damage. We hypothesized that overheating of the heating pad and uneven distribution of temperature led to kidney damage. Therefore, the maximal temperature of commonly used heating pads must be tightly controlled to avoid overheating, which may cause kidney or tissue injury, may falsify the experimental data and could influence the study results.

Comparison of buprenorphine and meloxicam for postsurgical analgesia in rats: effects on body weight, locomotor activity, and hemodynamic parameters.

Buprenorphine is administered to humans and animals for postoperative pain management, although its use is associated with complications. Alternative analgesics, including the nonsteroidal antiinflammatory meloxicam, are available, but information on their postoperative effects is limited. The objective of the present study was to compare buprenorphine (0.03 mg/kg SC twice daily for 3 d) with meloxicam (2 mg/kg SC initial dose followed by 1 mg/kg SC once daily for 2 d) by assessing parameters relating to postsurgical recovery in rats that underwent surgical implantation of radiotelemetric transducers. Rats treated after surgery with buprenorphine showed greater reductions in body weight, food consumption, locomotor activity, and nighttime heart rates than did meloxicam-treated rats. Buprenorphine and meloxicam treatments both had stimulatory effects on mean arterial pressure and daytime heart rate measurements, although effects on nighttime mean arterial pressure were greater in the buprenorphine-treated rats. In summary, the lesser physiologic changes associated with meloxicam, as compared with buprenorphine, suggest that meloxicam offers advantages for use as a postoperative analgesic after laparotomy and radiotelemetric transducer implantation in rats.

Reported analgesic and anaesthetic administration to rodents undergoing experimental surgical procedures.

A structured literature review was carried out to assess recent trends in the administration of analgesics and anaesthetics to laboratory rats and mice undergoing surgical procedures. The ScienceDirect database was used to systematically identify studies published in peer-reviewed journals over two periods (2000-2001 and 2005-2006), 86 studies from each time period were included in the review. The total number of animals that underwent surgery, species used, type of procedure, anaesthetic regimen and analgesic administration were noted for each study. There was an increase in the reported administration of systemic analgesics from 10% in 2000-2001 to 20% in 2005-2006. Buprenorphine was the most commonly reported analgesic in both periods (2000-2001: 78%, 2005-2006: 35%) and reporting the use of non-steroidal anti-inflammatory drugs increased from 11% to 53%. There was also a change in reported anaesthetic practices, notably a decrease in the use of pentobarbital and an increase in the use of isoflurane and ketamine/xylazine. Although reported administration of analgesics has increased and there has been some refinement in the selection of anaesthetic agents used, the findings of this review suggest that there is still significant scope for improvement with respect to the perioperative care of laboratory rodents.

Uterus transplantation in the rat: model development, surgical learning and morphological evaluation of healing.

OBJECTIVE: Experimental uterus transplantation is a growing research field with the aim to develop a treatment for women with absolute uterus factor infertility. The potential risks of surgery and immunosuppressive treatment involved in uterus transplantation need to be identified and minimized in appropriate animal models before clinical trials commence. The aim of the present study was to develop and evaluate a model for uterus transplantation in the rat that can be reproduced and used in future studies concerning critical aspects of uterine function after transplantation. DESIGN: Animal study. SETTING: University Hospital. SAMPLE: Uterine tissue sampled at different post-operative time points after non-rejecting uterus transplantation in rats. METHODS: Adult, virgin female rats of inbred Lewis strain served as donors and recipients of uterine transplants. Two individuals with no previous microsurgical training performed the transplantations and learning curves were recorded. When transplant survival exceeded 70% for both surgeons, 15 animals were transplanted and grafted uteri were evaluated at 1, 7 and 21 days after surgery by assessment of morphology and enumeration of infiltrating neutrophilic granulocytes. MAIN OUTCOME MEASURES: Animal survival, graft survival, surgery times, uterine morphology, enumeration of infiltrating neutrophilic granulocytes. RESULTS: Both surgeons gained the necessary microsurgical skills needed to achieve above 70% transplant survival at a similar rate. The signs of post-operative inflammation on day one after transplantation were minor and further reduced at later time points. CONCLUSION: A reproducible model for uterus transplantation in the rat was developed, which can be used in future studies concerning uterine function after allogenic transplantation.

A transgenic rat with the human ATTR V30M: a novel tool for analyses of ATTR metabolisms.

Amyloidogenic transthyretin (ATTR) is the pathogenic protein of familial amyloidotic polyneuropathy (FAP). To establish a tool for analyses of ATTR metabolisms including after liver transplantations, we developed a transgenic rat model expressing human ATTR V30M and confirmed expressions of human ATTR V30M in various tissues. Mass spectrometry for purified TTR revealed that rat intrinsic TTR and human ATTR V30M formed tetramers. Congo red staining and immunohistochemistry revealed that nonfibrillar deposits of human ATTR V30M, but not amyloid deposits, were detected in the gastrointestinal tracts of the transgenic rats. At 24h after liver transplantation, serum human ATTR V30M levels in transgenic rats that received livers from normal rats became lower than detectable levels. These results thus suggest that this transgenic rat may be a useful animal model which analyzes the metabolism of human ATTR V30M including liver transplantation studies.

Ketamine-xylazine-acepromazine anesthesia and postoperative recovery in rats.

We evaluated the effect of ketamine-xylazine-acepromazine anesthesia (31.25, 6.25, and 1.25 mg/kg subcutaneously, respectively) on postsurgical recovery in male Sprague-Dawley (Crl:SD) rats undergoing laparotomy with and without the postoperative analgesic ketorolac. Recovery was determined by changes in body weight (BW) and water intake. The time of ketorolac administration (5 mg/kg intramuscularly), 60 min after anesthetic injection, was based on return of the pedal withdrawal reflex in Long-Evans (HsdBlu:LE) rats undergoing stereotaxic surgery in a separate experiment. Results were compared with those of housing and anesthesia controls as well as of laparotomized rats receiving a single sugared treat for nonpharmacologic management of postoperative pain. Surgery took place on day 0; the first 24 h postsurgery was considered the "acute phase," and days 1 through 4 comprised the "recovery phase." Results suggest that 1) the anesthetic mixture is fast- and long-acting and provides sufficient immobility, loss of consciousness, and analgesia; 2) during the acute phase, rats subjected to laparotomy did not lose more BW than rats exposed to anesthesia alone; 3) water intake during both phases did not significantly differ between treatment groups; 4) postsurgical ketorolac administration did not minimize BW loss during the acute phase nor cause any adverse effects under this anesthetic regimen; and 5) provision of single sugared treats had salutary effects on BW recovery. This finding suggests that postsurgical BW loss after use of this anesthetic mixture is due to distress unrelated to pain; this nonpain distress may have masked potential beneficial effects of ketorolac.

Progesterone counteracts estrogen-induced increases in neurotrophins in the aged female rat brain.

Neurotrophin alterations have been associated with normal aging and age-related neurodegenerative disease, as well as cognitive status. Estrogen influences expression of mRNA and protein of neurotrophins and their receptors, and affects cognitive performance in young ovariectomized (Ovx) rats. The current investigation evaluated whether estrogen or estrogen plus progesterone affects neurotrophin protein levels in cognitive brain regions in the aged Ovx rat. While estrogen treatment increased BDNF, NGF, and NT3 levels in entorhinal cortex, progesterone abated the effects of estrogen resulting in neurotrophin levels comparable to aged Ovx rats not given hormone. Our findings suggest that the aged female brain is responsive to estrogen in cognitive brain regions, and that progesterone can reverse these estrogen effects.

Ventral approach to the lumbar spine of the Sprague-Dawley rat.

Lumbar intervertebral disc repair is an important tissue-engineering research area. In creating an in vivo rat model to evaluate repair techniques, the authors developed a surgical transperitoneal approach that permits the easy exposure of four lumbar vertebral bodies with no surgery-related peri- or postoperative complications.

Laparoscopy of rats with experimental liver metastases: a method to assess new humane endpoints.

Metastatic disease to the liver is one of the major factors determining the outcome of colonic resection with curative interventions in human patients. Therefore, animal models for studies of liver metastasis have been developed. Humane endpoints are needed for the evaluation of the animal condition. Liver metastases were modelled by hepatic subcapsular injection of a syngeneic rat colon cancer cell line (DHD/K12-PROb) in BDIX/OrlIco rats. In this study, we present a detailed description of a laparoscopic technique for the direct inspection of liver metastases. That way a qualitative impression of the metastases was obtained. We suggest, as a new humane endpoint, that one animal should only have 1-2 separately growing metastases, each of a maximum size of 10 mm(2). In future, the method has to be developed further to measure the size of the metastases in a more quantitatively precise manner. Although the animal has to be anaesthetized each time, laparoscopy is considered a minor surgical procedure as only two small puncture wounds are made through the abdominal wall. Because laparoscopy offers a direct view of the hidden tumours and their sizes, as well as of possible complications (e.g. peritoneal tumour growth), one can prevent unnecessary discomfort. We therefore think the advantages outweigh the disadvantages, as laparoscopy helps to avoid the unnecessary suffering due to large tumours which may only be detected at late stages by conventional procedures.

In vivo regulation of growth hormone-stimulated gene transcription by STAT5b.

The long-term effects of growth hormone (GH) are mediated through coordinated changes in gene expression that are the outcome of interactions between hormone-activated signal transduction pathways and specific feedback loops. Recent studies in mice have implicated the transcription factor STAT5b as part of the GH-regulated somatic growth pathway, because mice lacking this protein showed diminished growth rates. To assess the role of Stat5b in GH-stimulated gene expression, we have delivered modified versions of the protein to the liver of pituitary-deficient male rats by quantitative adenovirus-mediated gene transfer. In pilot studies in cell culture, both constitutive-active and dominant-negative STAT5b showed appropriate binding properties toward a specific DNA response element. After in vivo expression, neither protein prevented nuclear accumulation of STATs 1 and 3 in the liver. Dominant-negative STAT5b completely inhibited GH-stimulated transcription of genes encoding the growth-promoting proteins IGF-I, IGF-binding protein-3 (IGFBP-3), and acid-labile subunit (ALS), which comprise the major circulating IGF-I complex, and blocked expression of the GH inhibitors SOCS-1, SOCS-2, and CIS, but had little effect on induction of SOCS-3. Constitutive-active STAT5b stimulated robust transcription of IGF-I, ALS, and IGFBP-3 in the absence of hormone but did little to modify GH-mediated activation of SOCS family genes. An adenovirus encoding EGFP was without effect. These results, in addition to establishing STAT5b as one of the key agents of GH-stimulated gene transcription, demonstrate the feasibility of using in vivo gene transfer to target and dissect the functions of distinct components of complex hormone-activated signal transduction pathways.