Late preconditioning induced by NO donors, adenosine A1 receptor agonists, and delta1-opioid receptor agonists is mediated by iNOS.

Abstract

Although ischemia-induced late preconditioning (PC) is known to be mediated by inducible nitric oxide (NO) synthase (iNOS), the role of this enzyme in pharmacologically induced late PC remains unclear. We tested whether targeted disruption of the iNOS gene abrogates late PC elicited by three structurally different NO donors [diethylenetriamine/NO (DETA/NO), nitroglycerin (NTG), and S-nitroso-N-acetyl-penicillamine (SNAP)], an adenosine A1 receptor agonist [2-chloro-N6-cyclopentyladenosine (CCPA)], and a delta1-opioid receptor agonist (TAN-670). The mice were subjected to a 30-min coronary occlusion followed by 24 h of reperfusion. In iNOS knockout (iNOS-/-) mice, infarct size was similar to wild-type (WT) controls, indicating that iNOS does not modulate infarct size in the absence of PC. Pretreatment of WT mice with DETA/NO, NTG, SNAP, TAN-670, or CCPA 24 h before coronary occlusion markedly reduced infarct size. In iNOS-/- mice, however, the late PC effect elicited by DETA/NO, NTG, SNAP, TAN-670, and CCPA was completely abrogated. Furthermore, in WT mice pretreated with TAN-670 or CCPA, the selective iNOS inhibitor 1400W also abolished the delayed PC properties of these drugs; 1400W had no effect in WT mice. These data demonstrate that iNOS plays an obligatory role in NO donor-induced, adenosine A1 receptor agonist-induced, and delta1-opioid receptor agonist-induced late PC, underscoring the critical role of this enzyme as a common mediator of cardiac adaptations to stress.

• Authors: Yiru Guo, Adam B Stein, Wen-Jian Wu, Xiaoping Zhu, Wei Tan, Qianhong Li, Roberto Bolli
• Journal: American journal of physiology. Heart and circulatory physiology (Am J Physiol Heart Circ Physiol) Vol. 289 Issue 5 Pg. H2251-7 (Nov 2005) ISSN: 0363-6135 [Print] United States
• PMID: 16006548 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Adenosine A1 Receptor Agonists
• Amidines
• Benzylamines
• DOR-1 protein, mouse
• Enzyme Inhibitors
• N-(3-(aminomethyl)benzyl)acetamidine
• Nitric Oxide Donors
• Receptors, Opioid, delta
• 2-chloro-N(6)cyclopentyladenosine
• Adenosine

Topics

• Adenosine (analogs & derivatives, pharmacology)
• Adenosine A1 Receptor Agonists
• Amidines (pharmacology)
• Animals
• Benzylamines (pharmacology)
• Blood Pressure (drug effects)
• Body Temperature (drug effects)
• Enzyme Inhibitors (pharmacology)
• Heart Rate (drug effects)
• Ischemic Preconditioning, Myocardial
• Male
• Mice
• Mice, Knockout
• Myocardial Infarction (pathology)
• Myocardium (pathology)
• Nitric Oxide Donors (pharmacology)
• Receptors, Opioid, delta (agonists)