RESUMO
Avoidance of ice formation during cooling can be achieved by vitrification, which is defined as solidification in an amorphous glassy state that obviates ice nucleation and growth. We show that a vitrification approach to storing vascular tissue results in markedly improved tissue function compared with a standard method involving freezing. The maximum contractions achieved in vitrified vessels were >80% of fresh matched controls with similar drug sensitivities, whereas frozen vessels exhibited maximal contractions below 30% of controls and concomitant decreases in drug sensitivity. In vivo studies of vitrified vessel segments in an autologous transplant model showed no adverse effects of vitreous cryopreservation compared with fresh tissue grafts.
Assuntos
Vasos Sanguíneos/transplante , Criopreservação/métodos , Angiotensina II/farmacologia , Animais , Prótese Vascular , Bradicinina/farmacologia , Relação Dose-Resposta a Droga , Histamina/farmacologia , Humanos , Veias Jugulares/anatomia & histologia , Veias Jugulares/transplante , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Norepinefrina/farmacologia , Coelhos , Temperatura , Vasoconstritores/farmacologia , Veias/anatomia & histologia , Veias/transplanteRESUMO
Accelerated coronary atherosclerosis of cardiac allograft occurs in 30-40% of cardiac transplant patients and remains an unsolved clinical problem. The etiology is unknown and anti-platelet drugs are used without conspicuous success. The inhibitory effect of the octapeptide, angiopeptin on coronary atherosclerosis was studied in a previously described rabbit heterotopic cardiac transplant model where allograft rejection is prevented by daily administration of cyclosporin A (CsA, 10 mg/kg per day s.c.). Twenty male New Zealand white rabbits (2.6-2.8 kg) received a heterotopic cardiac transplant from rabbits of the same strain. Donors and recipients were fed a 0.5% cholesterol diet 1 week prior to transplantation which was continued for the recipient until death 6 weeks later. The control group (n = 16) received CsA and saline injections twice daily and the treatment group (n = 4) received CsA and angiopeptin (60 micrograms/rabbit daily s.c.) in 2 divided doses. The treatment began after completion of the transplantation. Coronary artery transplant atherosclerosis was uniformly distributed (tubular) in the entire length of the coronary arteries. Angiopeptin inhibited the intimal hyperplasia in the transplanted heart from 47.5 +/- 2.4% (mean +/- SE) to 25.0 +/- 6.9% and in the native heart from 24.2 +/- 1.4% to 15.7 +/- 1.5%. The intimal hyperplasia is expressed as area of intimal hyperplasia/total vessel area x 100%. A similar inhibition by angiopeptin was seen in lipid deposition in the donor ascending aorta which is transplanted with the heart. Angiopeptin attenuated significantly the hyperplasia and the lipid deposition of the native coronary arteries and aorta but to a lesser extent.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Arteriosclerose/prevenção & controle , Transplante de Coração , Oligopeptídeos , Somatostatina/análogos & derivados , Sequência de Aminoácidos , Animais , Arteriosclerose/patologia , Vasos Coronários/patologia , Metabolismo dos Lipídeos , Masculino , Dados de Sequência Molecular , Oligopeptídeos/farmacologia , Peptídeos Cíclicos , Coelhos , Fatores de TempoRESUMO
Increases in urinary excretion of immunoreactive thromboxane B2 (i-TXB2), the stable break-down product of thromboxane A2, have been described in kidney allograft rejection in patients. We investigated these findings by monitoring daily urine i-TXB2 excretion in a heterotopic cardiac allograft rat model using Lewis rats as recipients. In order to obtain differences in allograft survival, a donor was used that was either ACI or LewisxBrown Norway F1 (LxB-NF1). The ACI-to-Lewis model rejected on day 6.2 +/- 0.2 (n = 6). The LxB-NF1-to-Lewis model received, in addition, azathioprine (5 mg/kg/daily) and rejected on day 9.1 +/- 0.8 (n = 9). Urinary i-TXB2 excretion increased significantly in both groups, compared with i-TXB2 values measured following sham surgery or isograft transplantation. Thus increases in urinary i-TXB2 appear to be associated with cardiac allograft rejection.
Assuntos
Rejeição de Enxerto , Transplante de Coração , Tromboxano B2/urina , Tromboxanos/urina , Animais , Histocompatibilidade , Masculino , Ratos , Ratos Endogâmicos ACI , Ratos Endogâmicos Lew , Especificidade da Espécie , Tromboxano B2/imunologia , Fatores de TempoRESUMO
Three agents that significantly prolong cardiac allograft survival were tested in Lewis rats that were recipients of hearts from Lewis X Brown-Norway F1 hybrid donors. In the presence of azathioprine, the effects of daily administration of either the thromboxane antagonist (L 640,035), the platelet-activating factor (PAF) antagonist (BN 52021) or prednisolone were evaluated on the infiltration of cardiac allografts by syngeneic lymphocytes and platelets labeled with 111indium. As anticipated, platelet deposition was reduced by the thromboxane antagonist and unaffected by the PAF antagonist; the latter is likely due to the known absence of PAF receptors in rat platelets. In addition prednisolone had no effect. The increased accumulation of lymphocytes on days 4-5 was also unaffected by all three drugs. These experiments indicate that, in this model, graft survival is not necessarily related to lymphocyte and platelet infiltration of the graft. The data also provide evidence for the efficacy of the thromboxane receptor antagonist L 640,035 in preventing platelet deposition in vivo.
Assuntos
Plaquetas/citologia , Diterpenos , Transplante de Coração , Lactonas , Linfócitos/citologia , Glicoproteínas da Membrana de Plaquetas , Prednisolona/farmacologia , Receptores de Superfície Celular/antagonistas & inibidores , Receptores Acoplados a Proteínas G , Tromboxanos/farmacologia , Animais , Azatioprina/farmacologia , Movimento Celular/efeitos dos fármacos , Dibenzotiepinas/farmacologia , Ginkgolídeos , Masculino , Extratos Vegetais/farmacologia , Ratos , Ratos EndogâmicosRESUMO
This study describes the use of a blood perfusion apparatus to assess the renal function of isolated kidneys. Eight fresh kidneys were obtained from healthy rabbits and perfused with blood at 36 degrees C for 2 hours. Rabbit blood was drawn and diluted to a hematocrit of 25%. The kidneys were evaluated for their capacity to support life in an autograft model. Blood and urine samples were taken at regular time intervals during kidney perfusion. Serum creatinine was measured in surviving rabbits after transplantation. Over the course of the perfusion, arterial pressure was maintained at 87.2 +/- 5.5 mm Hg. The renal blood flow (3.7 +/- 1.0 ml/min per g) and urine output (0.11 +/- 0.04 ml/min per g) were continuously monitored. Glomerular filtration rate (0.29 +/- 0.02 ml/min per g) and fractional reabsorption (FR) of sodium and glucose indicated appreciable tubular function (FR(Na) = 67.9 +/- 8.5%, FR(Glu) = 91.2 +/- 5.8%). Protein was excluded from urine at 99.8% +/- 0.1%. After transplantation, the peak creatinine was 6.8 +/- 3.2 mg/dl at 1.90 +/- 0.92 days for the seven surviving rabbits and was above 16 mg/dl for the only rabbit that died 4 days after operation. The level of free hemoglobin generated at the end of the perfusion (2.6% +/- 2.8%) was correlated with the postoperative peak creatinine (r2 = 0.84). Perfusion of seven additional kidneys by using the roller pump lead to a final hemolysis of only 0.34 +/- 0.14%. Kidneys transplanted after 2 hours of blood perfusion were able to resume normal function and support life. Hemolysis was a measurable stress factor causing delayed function of the kidney after transplantation. Introduction of a roller pump significantly reduced the hemolysis.
Assuntos
Transplante de Rim/fisiologia , Rim/fisiologia , Preservação de Órgãos/instrumentação , Animais , Pressão Sanguínea , Sobrevivência de Enxerto/fisiologia , Hemólise , Técnicas In Vitro , Testes de Função Renal , Perfusão , Coelhos , Circulação RenalAssuntos
Diterpenos , Transplante de Coração , Lactonas , Extratos Vegetais/farmacologia , Animais , Azatioprina/farmacologia , Ciclosporinas/farmacologia , Ginkgolídeos , Rejeição de Enxerto , Sobrevivência de Enxerto/efeitos dos fármacos , Imunidade Celular , Fator de Ativação de Plaquetas/antagonistas & inibidores , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Fatores de Tempo , Transplante HomólogoAssuntos
Araquidonato Lipoxigenases/antagonistas & inibidores , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Coração , Inibidores de Lipoxigenase , SRS-A/antagonistas & inibidores , Tromboxanos/antagonistas & inibidores , Animais , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Transplante HomólogoAssuntos
Doença da Artéria Coronariana/patologia , Transplante de Coração , Oligopeptídeos/farmacologia , Somatostatina/análogos & derivados , Animais , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/prevenção & controle , Vasos Coronários/patologia , Sobrevivência de Enxerto/efeitos dos fármacos , Humanos , Peptídeos Cíclicos , Coelhos , Ratos , Somatostatina/farmacologia , Transplante Homólogo/efeitos adversosAssuntos
Araquidonato Lipoxigenases/antagonistas & inibidores , Benzopiranos/farmacologia , Catecóis/farmacologia , Cromanos/farmacologia , Rejeição de Enxerto/efeitos dos fármacos , Transplante de Coração , Inibidores de Lipoxigenase , Sulfetos/farmacologia , Tromboxano B2/biossíntese , Animais , Ciclosporinas/farmacologia , Leucócitos/patologia , Miocárdio/imunologia , Miocárdio/patologia , RatosAssuntos
Doença das Coronárias/prevenção & controle , Estradiol/uso terapêutico , Transplante de Coração , Animais , Colesterol/sangue , Colesterol na Dieta/administração & dosagem , Doença das Coronárias/etiologia , Doença das Coronárias/patologia , Ciclosporinas/administração & dosagem , Quimioterapia Combinada , Estradiol/administração & dosagem , Rejeição de Enxerto , Masculino , Prednisolona/administração & dosagem , CoelhosAssuntos
Veias Jugulares , Músculo Liso Vascular/transplante , Preservação de Órgãos/métodos , Angiotensina II/farmacologia , Animais , Bradicinina/farmacologia , Criopreservação/métodos , Histamina/farmacologia , Técnicas In Vitro , Veias Jugulares/fisiologia , Veias Jugulares/transplante , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/fisiologia , Norepinefrina/farmacologia , Coelhos , Transplante HomólogoRESUMO
The requirements of organ cryopreservation differ from those of conventional organ preservation. The encouraging results of Karow's group with dog kidneys transplanted after perfusion with more than 4 M dimethyl sulfoxide were based on an RPS-2 (renal preservation solution 2) vehicle solution, but transplantation of rabbit kidneys after perfusion with RPS-2 has not been reported. We evaluated RPS-2 in comparison to Euro-Collins solution (EC) using a modified technique for rabbit kidney autotransplantation and a computer-based organ perfusion machine designed for the introduction and removal of cryoprotective agents. Consistent success in rabbit kidney transplantation was found to depend on the anesthetic used, the hydration volumes administered, and direct ureter-to-ureter anastomosis. RPS-2 was found to be equivalent to EC for short-term (about 5 h) preservation by either perfusion or simple cold storage. However, good results with EC were associated with perfusion at 4 degrees C, recovery being significantly worse at 2 degrees C. In addition, we found that the solitary rabbit kidney is not able to fully compensate for the loss of the contralateral kidney, the result being persistent (to 3 weeks) mild elevation of serum creatinine, potassium, and calcium and persistent moderate reduction of serum phosphate. These results establish perfusates, perfusion conditions, transplantation techniques, computer-based perfusion control techniques, and a general clinical baseline that are permissive of further direct experiments on cryoprotectant introduction and removal.
Assuntos
Criopreservação/métodos , Transplante de Rim/métodos , Rim , Animais , Creatinina/sangue , Estudos de Avaliação como Assunto , Sobrevivência de Enxerto , Soluções Hipertônicas , Técnicas In Vitro , Transplante de Rim/fisiologia , Masculino , Perfusão , Coelhos , Circulação Renal , Soluções , Transplante AutólogoRESUMO
The effect of a thromboxane antagonist, L640,035 on platelet deposition in heart allografts was studied. Twenty Lewis rats received heterotopic allografts from Lewis x Brown-Norway F1 hybrid. All recipients received azathioprine (5 mg/kg/day). The rats were divided into three groups. Groups II and III were also treated daily with either the vehicle for L640,035 or L640,035 respectively. Syngeneic indium-111-labeled platelet deposition was determined in the allograft and the native heart at 6, 9, and 13 days after transplantation; group III was studied on the sixth and ninth day only. A rapidly increasing platelet deposition was seen in allografts from rats given azathioprine; whereas the thromboxane antagonist prevented the increase in platelet deposition on the ninth day.
Assuntos
Dibenzotiepinas/farmacologia , Transplante de Coração , Agregação Plaquetária/efeitos dos fármacos , Animais , Azatioprina/farmacologia , Plaquetas , Sobrevivência de Enxerto/efeitos dos fármacos , Índio , Miocárdio/patologia , Radioisótopos , Ratos , Ratos Endogâmicos Lew , Receptores de Prostaglandina/efeitos dos fármacos , Receptores de Tromboxanos , Tromboxano A2/antagonistas & inibidoresRESUMO
Tandem Scanning Confocal Microscopy (TSCM) is a non-invasive form of vital microscopy which can be used to evaluate superficial uriniferous tubules in living kidneys. Because TSCM has a number of advantages over conventional microscopic examination of renal biopsies, the present study was undertaken to determine whether the histopathological images obtained by TSCM can be correlated with post-transplant renal function. The kidneys of New Zealand male rabbits were harvested, flushed in Euro-Collins solution, and stored at 0-2 degrees C for periods of 24, 48, 67 and 72 hours prior to transplantation. As expected, there was a significant deterioration in post-transplant renal function as the kidneys were stored for longer periods of time. TSCM observations of the kidneys prior to their transplantation revealed characteristic histopathological changes of the proximal convoluted tubules which correlated closely with post-transplant renal function. These observations support the proposed use of TSCM in evaluating human donor kidneys prior to their transplantation.
Assuntos
Sobrevivência de Enxerto/fisiologia , Nefropatias/patologia , Transplante de Rim/métodos , Transplante de Rim/patologia , Túbulos Renais/citologia , Túbulos Renais/patologia , Microscopia Confocal/métodos , Valor Preditivo dos Testes , Animais , Nitrogênio da Ureia Sanguínea , Creatina/sangue , Nefropatias/sangue , Nefropatias/fisiopatologia , Transplante de Rim/efeitos adversos , Túbulos Renais/fisiopatologia , Masculino , Microscopia Confocal/instrumentação , Coelhos , Recuperação de Função Fisiológica/fisiologiaRESUMO
Sex related differences in the blood protein patterns of male and female rats and humans have been studied by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. In rats, a prominent band of mol.wt. 74000--78000 is seen in females in far greater quantity than in males, castrated males or ovariectomized females. A secondary band of 100000 is seen under non-reducing conditions in female rats that is absent in males. In humans, bands of 92000 and 88000 mol.wt. appear to be variable in concentration in men although relatively constant in women. The above differences are observable only if serum albumin is removed from the samples before electrophoresis. The results suggest that each sex has its own characteristic blood protein pattern.
Assuntos
Proteínas Sanguíneas/análise , Albumina Sérica , Caracteres Sexuais , Adolescente , Adulto , Animais , Eletroforese das Proteínas Sanguíneas , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Masculino , Peso Molecular , RatosRESUMO
The antirejection eicosanoids--PGE2, (PGD2), and PGI2--have an attenuating effect on T-cell proliferation by inhibition of IL-1, IL-2, and class II antigen expression on macrophages, and the prorejection eicosanoids--TXA2, LTB4, LTC4, and LTD4--enhance T-cell proliferation. LTB4 stimulates IL-1 and IL-2 formation and expression of IL-2 receptor. The mechanism of enhancement of T-cell proliferation by TXA2 has not been demonstrated. LTC4 and LTD4 promote gamma-interferon release and can replace IL-2 as a stimulator of gamma-interferon. PAF at high concentrations inhibits lymphocyte proliferation. The eicosanoids interfere with the same mechanisms as CsA and corticosteroids on T-cell clonal expansion. In experimental organ transplantation, corticosteroids can be replaced by compounds preventing the formation or expression of the prorejection eicosanoids or analogs of antirejection eicosanoids as well as by PAF antagonists. In addition, these drugs exert synergistic effect with CsA and azathioprine.