Guba, Markus and Steinbauer, Markus and Buechner, Michael and Froehlich, Dieter and Farkas, Stefan and Jauch, Karl-Walter and Anthuber, Matthias (2000) Differential effects of short-term ACE- and AT1-receptor inhibition on postischemic injury and leukocyte adherence in vivo and in vitro. SHOCK, 13 (3). pp. 190-196. ISSN 1073-2322
Full text not available from this repository. (Request a copy)Abstract
There is recent evidence that angiotensin-converting enzyme (ACE) inhibition reduces postischemic injury and angiotensin II receptor inhibition may have similar effects. We therefore further characterized the role of ACE- vs. AT1-receptor inhibition on cell injury and temporal association of leukocyte endothelial interaction in response to ischemia-reperfusion. A combined in vivo and in vitro study comparing the ACE inhibitor enalapril and the AT1-receptor antagonist losartan was performed. The extent and temporal correlation of cellular damage (propidium-iodide staining), microvascular perfusion failure and leukocyte-endothelial interaction (leukocyte adherence) were investigated by means of intravital microscopy, after the application of hemodynamically ineffective doses of enalapril and losartan (5 mg/kg). A hamster dorsal skinfold model with a 4-h tourniquet ischemia was used. In vitro, the effect of enalapril and losartan on polymorphonuclear cell (PMN) adherence, as well as adhesion molecule expression (ICAM-1, VCAM-1), on hypoxia- or IL-1 beta-stimulated endothelial cells (HUVEC) was assessed using a PMN-adhesion assay and flow cytometry, respectively. Ischemia-reperfusion responses revealed a biphasic pattern, comprised of an early phase (30 min) of acute cellular damage and microvascular perfusion failure, followed by a late increase (240 min) in leukocyte adherence in vivo. Enalapril significantly reduced early cellular damage, microvascular perfusion failure, and leukocyte adherence in response to ischemia-reperfusion. Conversely AT1 receptor inhibition with losartan proved to be ineffective at attenuating postischemic microcirculatory disorders (leukocyte-endothelial interactions, microvascular perfusion failure) and aggravated cellular injury. In vitro, enalapril reduced PMN adherence and ICAM-1 and VCAM-1 expression, while losartan was ineffective in the same respect. Following ischemia-reperfusion injury; ACE- versus AT1-receptor inhibition induce differential effects concerning the extent and temporal association of cell injury and leukocyte-endothelial interaction. The use of enalapril combines the beneficial effects of preventing cell and vascular injury immediately after reperfusion, with a delayed inhibition of the inflammatory response. Since the AT1-receptor inhibitor losartan did not mimic effects obtained with ACE inhibition, it is conceivable that the responses in ischemia-reperfusion are mediated by a non-angiotensin II-AT1 receptor-dependent mechanism.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CONVERTING ENZYME-INHIBITION; RAT SKELETAL-MUSCLE; ENDOTHELIAL-CELLS; ISCHEMIA-REPERFUSION; TEMPORAL CORRELATION; NITRIC-OXIDE; ANGIOTENSIN; ISCHEMIA/REPERFUSION; MECHANISMS; ENALAPRIL; intravital microscopy; enalapril; losartan; adhesion molecules; ischemia-reperfusion injury |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Anästhesiologie Medicine > Lehrstuhl für Chirurgie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 07 Jun 2022 04:49 |
| Last Modified: | 07 Jun 2022 04:49 |
| URI: | https://pred.uni-regensburg.de/id/eprint/42811 |
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