Objective To establish a simple, valid rat orthotopic left lung transplantation model with the improved operation technique. Methods One hundred and thirty-six male SD rats were randomly divided into donor （n = 68） and recipient （n = 68）, transplantation were performed by using the improved cuff anastomosis technique. Results Time of donor lung perfusion-picking, donor lung vessel cuff anastomosis and recipient vessel anastomosis was 13±2 min, 9±1 min, 10±1 min respectively, the operative time was 60±3 min. In 68 rats of operations, successful rate was 88%（60/68）, anastomotic stoma leak in one rat, lung congestion 3 rats, lung atelectasis 4 rats. The shortest survival time was 1 day, there were 53 rats whose survival time was longer than 12 days. The chest computed tomography showed no atelectasis and blood gas analysis manifested good respiratory function. Conclusion The improved three cuff anastomosis technique offers a simple, valid, cheap and useful method,it can establish rat orthotopic left lung transplantation model successfully.
Objective To establish a reliable rats model of orthotopic liver transplantation with non-heart beating donors. Methods The model was established with modified double-cuff method. According to obtain pre-liver warm ischemia time experiencing non-heart-beat the rats were divided into 3 groups: 10 min (R10 group), 20 min (R20 group) and 30 min (R30 group), then one week survival after operation was compared in rats. Results The operative time of donor was 30 min approximately except warm ischemia time and the cold preservation time of donor liver was 1 h. The anastomotic time for suprahepatic vena cava was 12-22 min (mean 15 min). The anastomotic time for portal vein and infrahepatic vena cava was about 2 min and 1 min, respectively. The anhepatic phase sustained 14-24 min (mean 19 min). The operative time of receptor was 50-65 min (mean 60 min). Twelve rats died at 24 h after operation, which was considered as operative failure. The success rates of operation in R10 group, R20 group, and R30 group were 95% (19/20), 80% (16/20), and 65% (13/20), respectively. After one week the survival rate was 95% (18/19), 81% (13/16), and 54% (7/13), respectively. Conclusions Improved non-heart donor liver transplantation model of rat on the basis of Kamada’s “twocuff technique” acts as a good simulation in clinical non-heart-donor liver transplantation. This study showes that rat liver can tolerate warm ischemia time less than 30 min, the short-term survival after transplantation can reach satisfactory results. However, long-term survival requires further study.
Objective To observe the plastic changes of sensory nerve in terms of structure and function when targetorgan changed through making the rat model of nerve regeneration by anastomosing the proximal end of sensory nerve and the distal end of motor nerve. Methods Thirty adult SD rats (male or female), weighing 200-250 g, were randomized into three groups (n=10 per group). The left upper l imb of the each rat was used as the experimental side, while the right upper l imb as the control side. In group A, the medial antebrachial cutaneous nerve was cut 5 mm away from its origin and its proximal end was anastomozed end-to-end to the distal end of musculocutaneous nerve. In group B, the musculocutaneous nerve was cut 5 mm away from its nerve entry point and the proximal end of medial antebrachial cutaneous nerve were anastomozed end-to-end to the distal end of musculocutaneous nerve. In group C, medial antebrachial cutaneous nerve and musculocutaneous nerve were cut, without further anastomosis. Twenty-four weeks after operation, the general condition and the motion of the elbow joint of rats, the wet weight and muscle fiber cross-section area of the biceps brachii as well as the latent period and the ampl itude of the evoked potential were observed and the acetylchol inesterase (AchE) staining of nerve of proximal end of anastomosis was conducted. Results All the rats survived for 24 weeks with good general condition and without wound infection. The rats in groups A, B and C were lost the active flexion of left elbow joint after operation. The rats in groups A and B got recovered to some degree at 24 weeks. The behavioral evaluation showed that there were 7 l imbs in group A and 5 l imbs in group B scoredas 4-5 points, there was a significant difference when compared with group C (P lt; 0.05), but there was no significant difference between group A and group B (P gt; 0.05). Group A and group B were superior to group C in terms of the wet weight and the muscle fiber cross-section area of the biceps brachii (P lt; 0.05), but no significant difference between group A and group B was detected (P gt; 0.05). The evoked potential of the biceps brachii and motor nerve fibers in proximal end of anastomosis could be detected in both group A and group B. But there was no significant difference between group A and group B with respects of function recovery of elbow joint, the latent period and the ampl itude of the evoked potential of the biceps brachii and the quantity of motor nerve fiber in proximal end of anastomosis (P gt; 0.05). Conclusion The change of target organ leads to the sensory nerve plasticity structurally and functionally, which may provide a new approach for peripheral nerve repair.
Objective To make an experimental research of the tissue engineered rat submandibular glands (SMG) cells growing on a collagensponge scaffold under an optimal culture condition. Methods The Wistar rat (8 days old) SMG cells of the second generation were seeded onthesurface of the collagen sponge scaffold (5 mm×5 mm×2 mm) and were cultured under a physiologically optimal condition for 3 weeks. At 1, 2 and 3 weeks, the cultured cells were observed on their shapes and structures by the histological examination and the scanning electron microscopy. The cultured cells underwentthe immunohistochemistry research (the cytokratin 813,CK8.13;αsmooth muscular actin,αSMA) staining performed at 3 weeks of the culture, and the amylaseactivity analysis (the Amano method) performed at 1 day, 1, 2 and 3 weeks of the culture for an evaluation on the secretion function of the cells; the ultrastructures of the cells were also observed by the transmission electron microscopy for an identification of their origins. Results The observatio n under the scanning electron microscope showed that at 1 week after the cellseeding, the seeded cells were attached to the collagen sponge scaffold surface, with no cell process formed; at 2 weeks the cells increased, with formation of the cell process that was anchored on the collagen sponge scaffold surface; and at 3 weeks, the scaffold surfaceattached cells increased, with formation of thefiliform fibers in the surface layer of the cells. The immunohistochemistry staining showed that the cultured epithelial cells of SMG were bly positive for the specific antibody of CK8.13, and the myoepithelial cells were positive forthe specific antibody of αSMA. The transmission electron microscopy showed that in the surface layer of the cultured epithelial cells of SMG the microvilli,plasm crease, and zymogen granules were observed, with a big and ovalshaped nucleus in the cell, and mitochondria and rough endoplasmic reticulum in the cytoplasm of the cell. The amount of amylase secreted by the cells cultured with thecollagen sponge scaffolds increased at a different degree with an extension of the culturing time. Conclusion The collagen sponge has a satisfactory cell compatibility, and the SMG cells cultured with this kind of collagen sponge can keep their abilities of proliferation and differentiation and theirfunction of secretion. Therefore, this kind of cultured SMG cells can be used as the tissueengineered cells seeded in the scaffold.
Objective To explore a practical method of culturing discs organ system by observing the changes of the nucleus pulposus after the whole intervertebral discs (including cartilage end-plate, nucleus pulposus, and annulus fibrous)were cultivated. Methods A total of 335 intervertebral discs were taken out completely from 60 healthy SD rats (about150 g) aged 5-6 weeks of clear grade and rinsed by high osmotic sal ine solution containing heparin, then put to the culture plate after being divided into 5 groups randomly. The whole intervertebral discs were cultured with high osmotic (410 mOsmol/ kg) culture medium and changed the medium once every day, then the cell viabil ity (n=15), HE staining (n=15), Safranin O staining (n=15), and immunohistochemistry staining (n=2) were observed at 0, 3, 7, 14, and 21 days; RT-PCR result (n=5) was observed at 0, 3, 7, and 14 days. Results The cell viabil ity was not changed significantly within 14 days (P gt; 0.05) and was significantly lower at 21 days than at other time points (P lt; 0.01). The immunohistochemistry staining results for collagen type II were positive in nucleus pulposus cells at every time point. HE staining showed that the tissue integrity and morphology of the whole intervertebral discs were not changed within 14 days. Safranin O staining showed no significant difference in the matrix grey scale within 14 days (P gt; 0.05) and significant differences between 21 days and 0-14 days (P lt; 0.05). RT-PCR results showed that the mRNA expression of collagen type I increased with time, but the expressions of collagen type II, aggrecan, and decorin decreased, showing significant differences in the mRNA expressions of the matrix protein at each time point (P lt; 0.05). Conclusion High osmotic sal ine solution containing heparin could be used to cultivate the whole intervertebral discs, it is an ideal model for futher studies on physiology and pathology of intervertebral discs.
Objective To investigate the cellular compatibil ity of polyvinyl alcohol (PVA)/wild antheraea pernyisilk fibroin (WSF), and to explore the feasibil ity for tendon tissue engineering scaffold in vitro. Methods The solutions of WSF (11%), PVA (11%), and PVA/WSF (11%) were prepared with 98% formic acid (mass fraction) at a mass ratio of 9 : 1. The electrospinning membranes of WSF, PVA, and PVA/WSF were prepared by electrostatic spinning apparatus. The morphologies of scaffolds were evaluated using scanning electronic microscope (SEM). The tendon cells were isolated from tail tendon of 3-dayold Sprague Dawley rats in vitro. The experiment was performed using the 3rd generation cells. The tendon cells (1 × 106/mL) were cocultured with PVA and PVA/WSF electrospinning film, respectively, and MTT test was used to assess the cell adhesion rate 4, 12 hours after coculture. The tendon cells were cultured in PVA and PVA/WSF extraction medium of different concentration (1, 1/2, and 1/4), respectively; and the absorbance (A) values were detected at 1, 3, 5, and 7 days to evaluate the cytotoxicity. The composite of tendon cells and the PVA or PVA/WSF scaffold were observed by HE staining at 7 days and characterized by SEM at 1,3, 5, and 7 days. Results The solution of WSF could not be used to electrospin; and the solution of PVA and PVA/WSF could be electrospun. After coculture of tendon and PVA or PVA/WSF electrospinning membranes, the cell adhesion rates were 26.9% ±0.4% and 87.0% ± 1.0%, respectively for 4 hours, showing significant difference (t=100.400, P=0.000); the cell adhesion rates were 35.2% ± 0.6% and 110.0% ± 1.7%, respectively for 12 hours, showing significant difference (t=42.500, P=0.000). The cytotoxicity of PVA/WSF was less significantly than that of PVA (P lt; 0.05) and significant difference was observed between 1/2 PVA and 1/4PVA (P lt; 0.05). HE staining and SEM images showed that the tendon cells could adhere to PVA and PVA/WSF scaffolds, but that the cells grew better in PVA/WSF scaffold than in PVA scaffold in vitro. Conclusion PVA/WSF electrospinning membrane scaffold has good cell compatibility, and it is expected to be an ideal scaffold of tendon tissue engineering.
Objective To establish a repeatable, simple, and effective model of rat crush injury and crush syndrome (CS) so as to lay a foundation for further study on CS. Methods A total of 42 female Sprague Dawley rats (2-month-old, weighing 160-180 g) were divided randomly into the control group (n=6) and experimental group (n=36). The rats of the experimental group were used to establish the crush injury and CS model in both lower limbs by self-made crush injury mould. The survival rate and hematuria rate were observed after decompression. The biochemical indexes of blood were measured at 2, 4, 8, 12, 24, and 48 hours after decompression. The samples of muscle, kidney, and heart were harvested for morphological observation. There was no treatment in the control group, and the same tests were performed. Results Seven rats died and 15 rats had hematuria during compression in the experimental group. Swelling of the lower limb and muscle tissue was observed in the survival rats after reperfusion. The liver function test results showed that the levels of alanine transaminase and aspartate aminotransferase in the experimental group were significantly higher than those in the control group (P lt; 0.05). The renal function test results showed that blood urea nitrogen level increased significantly after 2 hours of decompression in the experimental group, showing significant difference when compared with that in the control group at 12, 24, and 48 hours after decompression (P lt; 0.05); the creatinine level of the experimental group was higher than that of the control group at 4, 8, 12, and 24 hours, showing significant difference at 8, 12, and 24 hours (P lt; 0.05). The serum K+ concentration of the experimental group was higher than that of the control group at all time, showing significant difference at the other time (P lt; 0.05) except at 2 hours. The creatine kinase level showed an increasing tendency in the experimental group, showing significant difference when compared with the level of the control group at 4, 8, 12, and 24 hours (P lt; 0.05). The histological examination of the experimental group showed that obvious edema and necrosis of the muscle were observed at different time points; glomeruli congestion and swelling, renal tubular epithelial cell degeneration, edema, necrosis, and myoglobin tube type were found in the kidneys; and myocardial structure had no obvious changes. Conclusion The method of the crush injury and CS model by self-made crush injury mould is a simple and effective procedure and the experimental result is stable. It is a simple method to establish an effective model of rats crush injury and CS.
Objective To explore the effect and mechanism of sleeve gastrectomy （SG） for type 2 diabetes mellitus （T2DM） in Goto-Kakizaki （GK） rats. Methods Thirteen male GK rats at 12 weeks of age were randomly divided into SG group （n=7） and sham operation group （SO group， n=6）， receiving SG surgery and sham operation respectively.Body weight， food intake in 24hours， fasting plasma glucose， plasma glucagon-like peptide-1 （GLP-1）， and plasma Ghrelin of rats in 2 groups were measured or tested before operation， 1， 4， 10， and 26 weeks after operation. In 10 weeks after operation， fecal energy content of rats in 2 groups was tested， in addition， oral glucose tolerance test （OGTT） and insulin tolerance test （ITT） were performed to investigate the glucose tolerance and insulin sensitivity. Results ①Body weight：there were no significant difference on body weight between the 2 groups （P＞0.05）. Compared with time point of before operation， the body weight of both 2 groups decreased in 1 week after operation （P＜0.01）， but increased in 10 weeks and 26 weeks （P＜0.01）. ②Food intake in 24 hours：compared with SO group， the food intake of SG group were lower in 4 weeks and 10 weeks after operation （P＜0.05）. Compared with time point of before operation， the food intake of SG group were lower in 1， 4， and 10 weeks after operation （P＜0.05）， but lower only in 1 week in SO group （P＜0.05）. ③Value of fasting glucose：compared with SO group， the value of fasting glucose in SG group were lower after operation （P＜0.01）. Compared with time point of before operation， the value of fasting glucose of SG group were lower after operation （P＜0.01）， but decreased in 1 week only in SO group （P＜0.01）. ④Level of serum GLP-1：compared with SO group， the levels of serum GLP-1 in SG group were higher in 4， 10， and 26 weeks after operation （P＜0.05）. Compared with time point of before operation， the levels of serum GLP-1 in SG group were higher in 4， 10， and 26 weeks after operation （P＜0.05）， but levels of serum GLP-1 in SO group didn’t change significantly （P＞0.05）. ⑤Level of serum Ghrelin：compared with SO group， the levels of serum Ghrelin in SG group were lower at alltime points after operation （P＜0.01）. Compared with time point of before operation， the levels of serum Ghrelin in SGgroup were lower at all time points after operation （P＜0.001）， but levels of serum Ghrelin in SO group didn’t change significantly （P＞0.05）. ⑥Areas under curves （AUC）：the AUC of OGTT and ITT test in SG group were both lower than those of SO group （P＜0.01）. Conclusion SG surgery can induce the level of fasting plasma glucose， and canimprove glucose tolerance and insulin sensitivity with significant changes of levels of plasma GLP-1 and Ghrelin， sugg-esting that SG surgery may be a potential strategy to treat patient with T2DM but without obesity or insulin resistance.
A acute partial obstructive hepatocholangitis model by selective ligation and injection of E coli into left hepatic bile duct was successfully founded in rat. Using parameters including mortality, mitochondrial glutamic oxalacetic transaminase and ornithine carbamoytransferase activity, pathological observation and blood culture of bacteria, we evaluated the model. The authors emphasize that this models is superior to the wole-bile-duct-challenged cholangitis model, which is characterized by liver injury.