Soy isoflavones modulate adipokines and myokines to regulate lipid metabolism in adipose tissue,skeletal muscle and liver of male Huanjiang mini-pigs

Although a growing body of evidence suggests that soy isoflavones help regulate lipid metabolism, the underlying mechanism has not yet been thoroughly clarified. The present study was undertaken to determine the effects of soy isoflavones on the expression of genes involved in lipid metabolism in different adipose tissue depots, skeletal muscle and liver of male Huanjiang mini-pigs, as well as the expression of adipokines and myokines. A total of 36 male Huanjiang mini-pigs were fed basal diet (control, Con), low-dose soy isoflavones (LSI) and high-dose soy isoflavones (HSI). The results showed that LSI and HSI regulated the expression of genes involved in the anabolism and catabolism of fatty acids in dorsal subcutaneous (DSA), abdominal subcutaneous (ASA) and perirenal (PRA) adipose tissue depots, as well as longissimus dorsi muscle (LDM) and liver. LSI and HSI also regulated the expression of adipokines in DSA, ASA and PRA, and the expression of myokines in LDM in male Huanjiang mini-pigs. In addition, soy isoflavones regulated plasma glucose, leptin and adiponectin contents after treatment for two months. Our results indicate that soy isoflavones, by regulating the expression of adipokines and myokines, may regulate the metabolism of lipids and could have potential therapeutic applications in lipid abnormalities.     

Combination splitting using both in situ and ex situ techniques in triple split liver transplantation in pigs

In situ splitting of cadaver livers has been reported to reduce cold ischemic damage, to avoid biliary complications, and to result in improved graft survival. In this study, which involved a wider application of split liver transplantation (SLT), we examined the effects of a technique combining both ex situ and in situ splittings in triple SLT in pigs and compared it to ex situ splitting alone. In the combination splitting group, the splitting between the right and left lobes was done in situ with perfusion of the left lobe with cold, lactated Ringer's solution; that between the lateral and medical right lobes was done ex situ in backtable surgery. The time required for in situ splitting was 28 ± 5 min. The time for backtable surgery and the total ischemia time were significantly shorter in the combination splitting group than that in the ex situ splitting group (P < 0.05). One day after triple SLT, the elevations in both serum AST and LDH in the ex situ splitting group were significantly greater than those in the combination splitting group (P < 0.05). We conclude that combination splitting may provide a technical improvement and have a beneficial effect on the clinical application of triple SLT. Received: 21 October 1997 Received after revision: June 9, 1998 Accepted: July 8, 1998     

The toxic mechanism and metabolic effects of atractyloside in precision-cut pig kidney and liver slices

The toxic and cellular metabolic effects of atractyloside, a diterpenoid glycoside, which causes fatal renal and hepatic necrosis in vivo in animals and humans, have been investigated in tissue slices prepared from male domestic pig kidney and liver. Precision-cut slices (200 μm thick) were incubated with atractyloside at concentrations of 200 μM, 500 μ M, 1.0 mM and 2.0 mM for 3 h at 37 °C and changes in lipid profile and pyruvate-stimulated gluconeogenesis investigated. Lipid peroxidative changes, reduced glutathione (GSH) and ATP content, the release of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), alanine and aspartate aminotransferase (ALT/AST) were also assessed. After 3 h of incubation, atractyloside caused a significant (P < 0.01) and concentration-dependent leakage of LDH and ALP from kidney slices. Only LDH leakage was significantly elevated in liver slices while ALT and AST leakage showed marginal increase. Atractyloside at concentrations of ≥200 μ M caused a significant increase in lipid peroxidation, but only in liver slices. However, atractyloside at concentrations of ≥200 μ M caused a marked depletion of GSH and ATP content in both kidney and liver slices. There was a marked decrease in total and individual phospholipid in kidney but not in liver slices. However, cholesterol and triacylglycerol levels were not affected by atractyloside in both kidney and liver slices. Renal and hepatic pyruvate-stimulated gluconeogenesis were significantly (P < 0.05) inhibited at atractyloside concentrations of ≥500 μM. Accumulation of organic anion p-aminohippuric acid (PAH) was also inhibited in renal cortical slices at atractyloside concentrations of ≥500 μM. These results suggest that the observable in vivo effect of atractyloside can be reproduced in slices and that basic mechanistic differences exist in the mode of toxicity in liver and kidney tissues. The data also raise the possibility that the mechanistic basis of metabolic alterations in these tissues following treatment with atractyloside may be relevant to target selective toxicity. Received: 21 January 1998 / Accepted: 23 March 1998     

Kinin B1 and B2 receptors in pig vessels: characterization of two monoreceptor systems

The coronary artery and renal vein of the adult pig are sensitive and reliable monoreceptor systems for studying kinin receptors. The pig coronary artery with intact endothelium is highly sensitive to bradykinin (BK, pEC₅₀ 8.6), while being insensitive to the B₁ receptor agonist, LysdesArg⁹BK. The tissue responds to BK with concentration-dependent relaxation, which is prevented by B₂ receptor antagonists, particularly dArg[Hyp³, Thi⁵, dTic⁷, Oic⁸]BK (HOE 140, pK_B 9.3), (E)-3-(6-acetoamido-3-pyridyl)-N-(N-{2, 4-dichloro-3-[(2-methyl-8-quinolinyl)oxy-methyl]phenyl}-N-methylaminocarbonylmethyl)acrylamide (FR 173657), a new non peptide compound (pK _B 9.3), while B₁ receptor antagonists (e.g. Lys[Leu⁸]desArg⁹BK) are inactive. The order of potency of kinin-related peptides in this vessel is: LysBK ≥ BK > [Hyp³]BK>[Aib⁷]BK, a sequence typical of a B₂ receptor system. Antagonists such as HOE 140 and FR 173657, at high concentrations reduce the maximum effect of BK and thus behave as noncompetitive antagonists. The kinin B₁ receptor was studied in the pig renal vein without endothelium and incubated for several hours in order to allow for the de novo formation of this functional site. After 7–8 h in vitro incubation, the vessel shows high sensitivity to LysdesArg⁹BK (pEC₅₀ 8.3) and is insensitive to BK. The pig renal vein responds to B₁ receptor agonists with concentration-dependent contraction which maintains a stable plateau and is prevented by selective B₁ receptor antagonists such as Lys[Leu⁸]desArg⁹BK (pK_B 6.7). The most active antagonist has been found to be desArg⁹HOE 140 (pA₂ 7.6) which acts as competitive antagonist in this preparation. Some B₂ antagonists (e.g. HOE 140) show weak (pK _B 6.1) anti-B₁ receptor activity while the non-peptide compound FR 173657 is inactive on the B₁ receptor and therefore acts as a potent and selective kinin B₂ receptor antagonist in the pig. The data obtained in this study allow us to compare the porcine B₂ and B₁ receptors with those of other species including man, and underline some interesting features that are unique to the porcine functional sites. Received: 9 April / Accepted: 20 June 1997     

Controlled trial of laparoscopic-assisted vs open colon resection in a porcine model

Background: Several series of laparoscopic colon resection have been reported in the literature with varied results; however, no controlled series of laparoscopic vs open colon resection has been reported. The purpose of this study was to determine the relative safety and adequacy of laparoscopic colon resection in a controlled trial using a porcine model. Methods: Domestic pigs (n=23) were randomly divided into two groups. Animals underwent either an open or laparoscopic-assisted segmental resection of the sigmoid colon. The open resections were performed through a 20-cm midline incision and the laparoscopic technique utilized five 12-mm ports. Laparoscopic resection took twice as long to complete as open resection (P<0.001). Return of gastric function was significantly faster in the laparoscopic group than in the open group (P<0.032). Results: No significant differences were found in total length of resection, proximal or distal margins, number of lymph nodes recovered, length of mesenteric vessel resected, or time to return of bowel function. At vivisection, more adhesions to the abdominal wall were noted in the open group (P<0.002). One death occurred in the laparoscopic group 2 h postoperatively (8.3% mortality) while all open group pigs survived. However, there was no statistically significant difference in mortality rates by chi-square analysis (P>0.5). Conclusions: Despite longer operative time, laparoscopic intervention is technically feasible, safe, and may offer significant postoperative benefits due to fewer abdominal adhesions.     

微囊化猪肝细胞培养的研究

目的　微囊包裹猪原代肝细胞并进行普通培养 ,观察肝细胞形态变化。方法　在不含小牛血清的RPMI 164 0培养基中培养 ,光镜下观察培养过程中肝细胞形态变化 ,检测不同时期培养上清中白蛋白及尿素含量。结果　微囊肝细胞可较长期存活 ,微囊肝细胞组与游离肝细胞组上清蛋白分泌在前 3d差异无显著性 (P >0 .0 5 ) ,4d后差异有显著性 (P <0 .0 5 ) ,而上清尿素合成在前 2d差异无显著性 (P >0 .0 5 ) ,3d后差异有显著性 (P <0 .0 5 )。结论　微囊材料可制备微囊化猪原代肝细胞 ,并进行体外培养 ,与游离肝细胞比较具有更好分泌合成功能。     

体外肝脏切除术对肝脏功能和结构的影响

方法:正常家猪13头，在体外静脉转流和4℃EuroCollins液持续灌注肝脏下行体外肝切除及自体残肝原位再植术。在手术中不同时相点检测肝组织能荷水平（EC）、线粒体呼吸活性（RCR）、动脉血酮体比值（AKBR）和肝脏病理变化。结果：在肝脏冷灌注时相，两组动物肝组织ATP、EC及AKBR水平较术前显著降低，RCR轻度降低。残肝植入后，术程平稳的6头动物，EC水平回升、RCR无显著变化、AKBR回升到0．7以上；术程不平稳的7头动物，RCR下降、EC进一步降低、AKBR仍低于0．5。冷灌注时肝脏组织结构基本保持完整，残肝再植复流后肝组织出现以肝腺泡第Ⅲ带为著的组织损害。结论：体外肝切除术造成肝脏损害的主要原因是再灌流损害；肝细胞能量代谢状态与手术动物的预后密切相关。     

Microskin grafting with Biobrane: a new application

A new grafting technique involving the combination of skin micrografts and Biobrane is reported. This is a modification of a method originally reported from China, utilising cadaveric allograft and skin micrografts. Experiments to verify the technique were carried out in a pig model. Small split-thickness skin autografts were finely minced into tiny particles and evenly spread on Biobrane. The micrografts with Biobrane were transplanted to controlled wounds in pigs. The expansion ratios of the micrografts were 10:1, they took well and the healing time of the wound was from 35–46 days. Based on successful animal experiments, we have used this technique successfully to treat severely burned patients.     

Intra-portal injection of 400-µm microcapsules in a large-animal model

To date, encapsulated grafts have usually been implanted in the peritoneal cavity. This site is, however, not ideal, mainly because of its low blood supply. We have investigated the feasibility of intra-portal injection of (400 microm) microcapsules in the pig. Ten-thousand microcapsules per kilogram body weight were injected into six Large White pigs. Portal pressure, various biological tests, portographies and liver histology were recorded before and at various time points after injection. As a result, portal pressure increased after injection (15+/-2.3 vs 8.7+/-1.7 mmHg) but remained within an acceptable range (<20 mmHg) and returned to normal values at 3 months (8.5+/-3.7 mmHg). During the 3-month follow up, liver function and liver tests remained stable. Portographies showed a homogenous implantation of the capsule, with the portal flow always directed to the liver. At histological examination after 3 months the capsules demonstrated various degrees of fibrosis. We can thus conclude that these results demonstrate that intra-portal injection of microcapsules is feasible in a large-animal model. Hemodynamic, biological and radiological results are similar to those observed in clinical free-islet transplantation.