The suppressive effect of resveratrol on protein kinase C theta in peripheral blood T lymphocytes in a rat liver transplantation model.

UNLABELLED: Our aim was to study the effect of resveratrol on the expressions of protein kinase C isotypes (PKC alpha, theta) in peripheral blood lymphocytes and on the expression of IkappaB kinase-beta (IKK beta) in lymphocytes in allografts in a rat liver transplantation model. METHODS: Orthotopic liver transplantations (OLT) were performed from Sprague Dawley rats to Wistar rats. The recipients were divided into two groups after OLT. In the RES group, resveratrol was given intraperitoneally once a day (100 mg kg(-1)) after OLT, whereas in the control group vehicle buffer was given. The expressions of PKC alpha, theta in peripheral blood lymphocytes, expression of IKK beta in lymphocytes in allograft, and survival periods were compared between the groups. RESULTS: The mean survival period after OLT in the RES group was significantly longer than that in control group (P < .05). On posttransplant day 7, the expression of PKC theta in peripheral blood lymphocytes in the RES group was significantly decreased compared with that in the control group (P < .05), whereas there was no obvious difference in the expressions of PKC alpha between the two groups (P > .05), and the positive rate of IKK beta protein in lymphocytes in allografts in RES group was significantly decreased compared with that in the control group (P < .05). CONCLUSION: Resveratrol showed an immunosuppressive effect on lymphocytes for allograft rejection in the rat. Down-regulation of the expression of PKC theta in peripheral blood lymphocytes may be part of the mechanism.

Novel magnetic rings for rapid vascular reconstruction in canine liver transplantation model.

OBJECTIVE: Magnetic rings were used for rapid vascular reconstruction in a canine liver transplantation model. MATERIALS AND METHODS: Thirty-two adult mongrel dogs weighing 13 to 16 kg were randomly selected as donors or recipients of transplantations. The recipients were randomly divided into two groups: group A (n = 10) had magnetic rings used for vascular reconstruction without venovenous bypass; group B (n = 6) had vascular reconstruction performed by continuous suturing with splenojugular venovenous bypass. RESULTS: In group A, the entire operative period was 3.24 +/- 0.49 hours, the durations of clamping the portal vein and the infrahepatic vena cava of the recipient were 5.89 +/- 2.27 minutes and 3.89 +/- 0.73 minutes, respectively. In group B, the entire operative period was 4.12 +/- 0.51 hours with the duration of clamping portal vein and infrahepatic vena cava, 28.33 +/- 6.04 minutes and 12.16 +/- 3.72 minutes (P < .01 vs group A). In group A, mean arterial pressure dropped during the anhepatic phase but recovered quickly after reperfusion. The fluid infusion was about 730.56 +/- 50.56 mL in the group A and a pressor agent was unnecessary. In group B, blood pressure dropped during the anhepatic phase and slowly recovered. The fluid infusion was about 2241.67 +/- 390.78 mL and a pressor agent was used to maintain the blood pressure of the recipient. No twist or thrombus was discovered in the anastomoses group A and the endothelium at the site of anastomosis was entire. In group B, errhysis was common in the anastomotic stomas. Nine of 10 dogs in group A survived more than 3 days, the longest being 8 days, whereas four of the six dogs in group B survived less than 3 days. CONCLUSION: The results showed that the anhepatic time was significantly shortened (about 5.89 +/- 2.27 minutes) in group A compared with group B and venovenous bypass was unnecessary. Magnetic rings could be used for rapid vascular reconstruction in canine liver transplantation model. The long-term results of this procedure should be clarified before it is applied in clinical practice in the future.

Immunosuppression by combined use of cyclosporine and resveratrol in a rat liver transplantation model.

INTRODUCTION: Despite continued progress in the development of immunosuppressive agents, allograft rejection remains an important cause of morbidity and mortality after liver transplantation. We examined the effect of intraperitoneal injection of cyclosporine (CsA) and resveratrol (Res) on allograft rejection after liver transplantation in rats. METHODS: Male Sprague-Dawley rats were selected as donors and male Wistar rats as recipients for a rejection model. The recipients were divided into three groups after orthotopic liver transplantation (OLTx): in the combination group both Res (100 mg/kg) and CsA (20 mg/kg) were given by intraperitoneal route once a day, whereas in the CsA group or control group CsA (20 mg/kg) or vehicle buffer was given. The survival period, serum chemistry, production of some cytokines, activation of transcription factor NF- kappaB, and histopathological findings were then compared among them. RESULTS: The mean survival period after OLTx in the combination group was significantly longer than that in the CsA group or control group (P < .05 and P < .01). On posttransplant day 7, the serum albumin level significantly improved, the serum total bile acid and alanine aminotransferase levels were significantly lower, the serum interleukin-2 and interferon-gamma levels were significantly lower, and the activation of transcription factor NF-kappaB in peripheral blood T lymphocytes was significantly suppressed in the combination group in comparison with those in the CsA group (all P < .05) or control group (all P < .01), and a histological examination revealed apparent difference in the severity of rejection between the combination group and CsA group (P < .05) or control group (P < .01). CONCLUSION: The combined use of CsA and Res has a stronger immunosuppressive effect on hepatocytes under allograft rejection in comparison with the sole use of CsA. Res might serve as a novel supplementary immunosuppressive agent for reducing the severity of hepatic allograft rejection in rats.

[The effect of Chinese cobra venom factor on guinea pig to rat cardiac xenotransplantation].

OBJECTIVE: In the guinea pig-to-rat cardiac xenotransplantation model, the effect of complement depletion by using Chinese Cobra Venom Factor(CVF) on hyperacute rejection was evaluated. METHODS: Cardiac xenograft from guinea pig was transplanted into the abdomen of rat after the recipient being given i.p. a dose of CVF 0.20 microgram/g. the recipients were divided into group A (control group), group B (only given CVF), group C (CVF + Cytoxan + Splenectomy), group D (Cytoxan + Splenectomy) Cytoxan was injected into the abdominal cavity with a dose of 60 mg/Kg. The survival time of xenograft was measured and histologic observation was carried out after the cardiac arrest. RESULTS: The survival time of xenograft ranged from 15 to 3,120 minutes. There were significant difference among group A compared with group B and C (P < 0.01), and no difference between group A and group D, as well as group B and C (P > 0.05). There were significant difference between group B and D, as well as group C and D(P < 0.01). The histologic observation proved that the hyperacute rejection in group A and D was milder than group B and C. CONCLUSION: The study reveals that CVF can prolong the xenograft time by depleting complement activities and restricting hyperacute rejection in this model. Further basic and clinical study of effect of CVF in xenograft transplantation is worthwhile.