Abstract
Postconditioning (PCD) is known to reduce infarct size (IS). Here, we investigated whether isoflurane, which is known to potentiate preconditioning, also potentiates PCD and whether NO is involved. Accordingly, open-chest rabbits underwent 30-minute coronary artery occlusion (CAO) followed by 3-hour coronary artery reperfusion (CAR). In control and postconditioned (4 cycles of 30s-CAR/30s-CAO after the 30-min CAO), rabbits were anesthetized with pentobarbital alone or in combination with isoflurane inhaled (i) throughout the experiment or (ii) only during CAR. With pentobarbital alone, PCD significantly reduced IS versus control (39 +/- 7% vs. 55 +/- 4% of the risk zone, respectively, P < 0.05). Isoflurane--0.5% throughout the experiment did not alter IS in both control and PCD groups. Isoflurane--2% throughout the experiment reduced IS in control (37 +/- 8%, P < 0.05 vs. pentobarbital alone) and enhanced the protective effect of PCD (IS = 21 +/- 3%, P < 0.05 vs. both control and PCD under pentobarbital alone). When isoflurane--2% was administered only during reperfusion, IS was not changed in control (53 +/- 3%) but combination with PCD reduced IS to 23 +/- 4% (P < 0.05 vs. both control and PCD under pentobarbital alone). L-arginine analog N-nitro-L-arginine methyl ester administered before reperfusion did not properly alter IS (53 +/- 6%) but abolished the effect of PCD alone (IS = 47 +/- 7%) or in combination with isoflurane--2% during reperfusion (55 +/- 3%). Thus, isoflurane potentiates PCD at reperfusion through a NO-dependent mechanism.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.