摘要:

In this experimental study we studied the effect of verapamil and iloprost on endothelin release in ischemia/reperfusion (IR) injury of the rat intestine. Endothelin levels in the portal blood and malondialdehyde (MDA), PGE2, and LTC4 levels in the intestinal tissue were determined. The MDA levels increased in the control group and this increase was reversed with iloprost, verapamil and both. The change in the LTC4 levels was insignificant between the groups. Iloprost reduced PGE2 and endothelin release, but verapamil was not as effective and no synergistic effect was encountered. The increased PGE2/LTC4 ratio was also reversed in the experimental groups, verapamil being less effective. Endothelin release seems to be related to both PGE2 levels and the PGE2/LTC4 ratio after mesenteric IR injury.

ISSN:0014-312X    

DOI:10.1159/000129320

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Microcirculatory nonperfusion of the intestinal mucosa may result in a subsequent prolongation of tissue ischemia, even after restoration of the mesenteric blood flow. It was hypothesized that there is a relationship between mucosal no-reflow and the amount of previously ischemic tissues during intestinal ischemia reperfusion. Accordingly, an examination was made of the changes in intestinal and gastric intramucosal pH (pHi) in dogs after a 120-min complete occlusion of the superior mesenteric artery (SMA) and those observed following ischemia of an ileal segment only. pHi, as an indicator of the adequacy of mucosal microcirculatory perfusion, was calculated by the tonometer technique. Baseline values of intestinal pHi (mean 7.25 ± 0.12) and gastric pHi (mean 7.23 ± 0.27) were determined in sham-operated animals. The 120-min intestinal ischemia caused a progressive fall in intestinal pHi to a mean value of approximately 6.8. Reperfusion resulted in a slow return to nearly normal pHi levels in the ileal segment, but essentially no intestinal pHi elevation was observed during the 90-min period following occlusion of the SMA. The gastric pHi remained at the control level during segmental intestinal ischemia reperfusion, but declined below the normal range following release of the occlusion of the SMA. It is proposed that continuing microcirculatory nonperfusion could explain the failure to demonstrate a postreperfusion elevation of pHi following complete occlusion of the SM

ISSN:0014-312X    

DOI:10.1159/000129321

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The electrical activity of the rectal detrusor was studied in 13 dogs. 10 electrodes were sutured serially to the rectal and lower sigmoid colon serosa. Electrical activity was recorded for 30 min/day for 10 days. Simultaneous electric and mechanical activity (recorded by a 6-French catheter connected to a pressure transducer) was also recorded with and without rectal distension by a condom balloon. Electrical activity was further determined after annular myotomy performed at different levels in the rectum and lower sigmoid colon. Pacesetter potentials (PP) were recorded from electrodes 3-10. They were triphasic, propagated caudally and had the same frequency and regular rhythm by all electrodes distal to the 3rd one. Frequency was constant in each dog from day to day. PP were accompanied by action potentials (AP) which had inconsistent frequencies and were accompanied by increased rectal pressure. Rectal distension led to an increase in both the frequency and amplitude of PP and AP. Rectal myotomy below the 3rd electrode resulted in PP and AP disappearing distal but not proximal to the cut, excluding the 1st and 2nd electrodes, which did not show activity. The results suggest that PP start at the 3rd electrode, which corresponds anatomically to the rectosigmoid junction (RSJ). AP cause contractile activity along the rectum. It seems that the RSJ is the site of a pacemaker triggering the PP that pace the AP which initiate the rectal contractile activity.

ISSN:0014-312X    

DOI:10.1159/000129322

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Complete ischemia in the left hindlimb was maintained for 3.5 h in 16 rats randomized into two equal groups. One group served as control, the other was treated with pentoxifylline before, during and after the ischemic period. The animals were killed 72 h later, and the anterior tibial muscles were prepared for histological investigation. The most severely damaged muscles had a central core with complete necrosis of all muscle fibers, disintegrated capillaries and no macrophage infiltration. This zone, which was called the area of no resorption, was surrounded by an area of incomplete necrosis with partly resorbed muscle fibers, intact capillaries and marked macrophage infiltration. The muscles were completely intact only in a narrow subfascial zone. The total areas of necrosis and the areas of no resorption were measured as percent of the cross-sectional area of each muscle. There was extensive necrosis in both groups. The infarcted area was 93% in the control group and 89% in the treated group (NS). The corresponding areas of no resorption were 23 and 6% (p = 0.01). The study indicates that pentoxifylline has some protective effect on ischemic muscle damage. However, this effect is marginal compared to moderate hypothermic treatment.

ISSN:0014-312X    

DOI:10.1159/000129323

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

To clarify the role of thromboxane A2 synthetase inhibitor (CV-4151) in the ischemia-reperfusion injury, the effect of CV-4151 was investigated in the gastrocnemius muscles of female Lewis rats. All tissues except femoral vessels were transected at the midthigh level and 4 h of ischemia was induced by vascular clamping of the femoral artery and vein, followed by 1 h of reperfusion. The sham group (n = 8) underwent the operation without ischemia-reperfusion; the control group (n = 8) with ischemia-reperfusion, and the CV-4151 group (n = 8) was pretreated with CV-4151 20 mg/kg. Skeletal muscle blood flow was measured by a hydrogen gas clearance method; the blood flow restored fully in the CV-4151 group, while it remained significantly low in the control group after 1 h of reperfusion (p < 0.05). Tissue levels of adenosine triphosphate (ATP) and creatine phosphate (PCR) were measured after 1 h of reperfusion; ATP decreased to 25% of non-ischemic values in the control group. In contrast, premedication with CV-4151 significantly improved the recovery of ATP (p < 0.01). PCR showed the same tendency as ATP; CV-4151 also improved the recovery of PCR significantly (p < 0.05), but CV-4151 did not prevent the production of lipid peroxides. Serum thromboxane B2 was determined by radioimmunoassay; in the sham and the CV-4151 group the level was significantly lower than in the control group (p < 0.05). These results indicate that pretreatment with CV-4151 promotes the recovery of skeletal muscle blood flow and maintains its viability after 4 h of ischemia, without preventing the generation of free radicals.

ISSN:0014-312X    

DOI:10.1159/000129324

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The mechanism by which FK506 (FK) prevents hepatic injury induced by ischemia/reperfusion was studied. Adult Sprague-Dawley rats were subjected to 60-min normothermic liver ischemia. Animals were divided into two groups: group I, controls, saline vehicle treatment; group II, FK treatment. FK (1 mg/kg/day, p.o.) was given for 4 consecutive days prior to inducing ischemia. In addition to a survival study, plasma levels of endotoxin and serum activities of tumor necrosis factor-α (TNF) and aspartate aminotransferase (AST) were assessed in the blood collected from suprahepatic vena cava. Results showed: (1) FK therapy significantly improved 7-day survival (80.0%) compared with nontreated animals (50.0%, p < 0.05); (2) both TNF and endotoxin were elevated following reperfusion, reaching maximum values at 3 h after reperfusion (217.0 ± 40.6 and 280.5 ± 31.4 pg/ml, respectively, in the control; mean ± SEM), and (3) serum activities of TNF and AST following reperfusion were substantially suppressed with FK treatment, whereas FK did not reduce the rise in endotoxin. These findings suggest that suppression of TNF production in response to endotoxemia might account at least in part for the protective effect of FK against ischemia-induced hepatic inj

ISSN:0014-312X    

DOI:10.1159/000129325

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The activation of the kallikrein-kinin system is thought to be one of the pathophysiological factors in acute pancreatitis. A radioimmunoassay for porcine, pancreatic tissue kallikrein was developed and used to measure levels in normal plasma and peritoneal fluid and in experimental, bile-induced (group and bile trypsin-induced (group B) acute pancreatitis in the pig. Normal porcine plasma and peritoneal fluid contained about 2.17 ± 0.11 and 1.91 ± 0.19 µg/l (SEM) tissue kallikrein, respectively. In experimental, acute pancreatitis there was a rapid rise in the plasma level of tissue kallikrein, followed by a slow increase to a final value of about 150% of the normal plasma level in both groups. In the peritoneal exudate a large increase (200-fold in group A and 2,000-fold in group in tissue kallikrein was seen, with a maximum within about 1/3 of the survival time, followed by a slow decrease until death in group B. In group A a smaller second peak was seen at about 2/3 of the survival time. Gelfiltration of peritoneal exudates showed complexes with alpha1-, alpha2-macroglobulin (α1α2-M), and alphai-proteinase inhibitor (α1-PI) and a large portion of free tissue kallikrein. The complexes with α1α2-M and the free tissue kallikrein were found to be enzymatically active when tested on chromogenic tripeptide substrate. The presence of large amounts of free and active tissue kallikrein in the peritoneal exudate leads us to the conclusion that tissue kallikrein may be a major cause of local release of kinins in acute pancr

ISSN:0014-312X    

DOI:10.1159/000129326

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

A study was undertaken to determine whether the cellular viability of the liver graft and posttransplantation outcome could the assessed by the graft energy status or change in water content prior to the transplantation procedure. These measurements were performed in a rat liver transplantation model. In a first set of experiments, the time for 50% survival of grafts preserved with UW solution or saline solution was determined. Grafts preserved with UW solution could be cold-stored for 19.9 h and grafted with a 50% success rate. The corresponding figure for saline-preserved grafts was 6.2 h. The energy status and water content of liver grafts preserved with UW solution for 19.9 h and livers preserved with saline solution for 6.2 h were compared. There were significant differences between livers preserved with UW solution and saline solution for ATP (p < 0.01), total adenine nucleotides (p < 0.05), ATP/ADP (p < 0.05) and energy charge levels (p < 0.05). ATP concentrations in the donor livers did not decrease significantly during cold storage when the success rate decreased from 100 to 0% after liver transplantation. The livers preserved with NaCl solution took up water during preservation. In contrast, the water content was reduced slightly in the livers preserved with UW solution and the differences were significant at all times. During cold storage using either the UW solution or saline solution for preservation, there were no significant time-related changes in the water content of the liver graft when the posttransplantation success rate decreased from 100 to 0% after liver transplantation. These results demonstrate that the metabolic energy status and the water content are not suitable indicators of the cellular viability of the liver graft.

ISSN:0014-312X    

DOI:10.1159/000129327

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

In the present study the effect of oxygenated Bretschneider cardioplegia on high-energy phosphates [adenosine triphos-phate (ATP), adenosine diphosphate (ADP) and creatine phosphate (CP)] and hemodynamics was evaluated in the isolated working rabbit heart. Hearts were obtained from 37 adult white Elco rabbits (3,100 ± 110 g). After a 20-min working period 14 hearts were arrested with Bretschneider cardioplegia (8 °C) oxygenated with 98% oxygen (O2) and 2% carbon dioxide in comparison to 14 hearts receiving Bretschneider solution saturated with 98% nitrogen (N2) and 2% carbon dioxide as a control group for either 60 or 90 min (O26O, O290, N260, N290 groups, n = 7). Seven hearts were used to determine preischemic baseline values of ATP, ADP and CP, 2 were excluded. The results showed a significantly poorer preservation of high-energy phosphates in hearts receiving oxygenated Bretschneider cardioplegia as compared to hearts receiving nitrogenated cardioplegia (p < 0.05). Postischemic recovery of hemodynamics did not demonstrate any statistically significant differences between the groups. However, the intragroup analysis showed a tendency towards weaker hemodynamic recovery in hearts treated with oxygenated cardioplegia. These results stay in contrast to the beneficial effect of oxygenated St. Thomas solution. In conclusion our findings suggest that oxygenated Bretschneider cardioplegia leads to significantly poorer preservation of high-energy phosphates and depressed hemodynamic recover

ISSN:0014-312X    

DOI:10.1159/000129328

出版商:S. Karger AG    

年代:1994

数据来源: Karger