Role of Adenosine Triphosphate-sensitive Potassium Channels in Coronary Vasodilation by Halothane, Isoflurane, and Enflurane

Content Provider	Scilit
Author	Crystal, George J. Gurevicius, Juozas Salem, Ramez M. Zhou, Xiping
Copyright Year	1997
Description	Journal: Anesthesiology Background Halothane, isoflurane, and enflurane cause coronary vasodilation and cardiac depression. This study was performed to assess the role of adenosine triphosphate (ATP)-sensitive potassium channels (KATP channels) in these effects. Methods Twenty-five thoracotomized dogs were anesthetized with fentanyl and midazolam. The left anterior descending coronary artery was perfused via either of two pressurized (80 mmHg) reservoirs. One reservoir was supplied with arterial blood free of a volatile anesthetic, and the second reservoir was supplied with arterial blood equilibrated in an oxygenator with a 1 minimum alveolar concentration of either halothane (0.9%, n = 10), isoflurane (1.4%, n = 8), or enflurane (2.2%, n = 7). Coronary blood flow (CBF) was measured using a Doppler flow transducer, and segmental shortening (SS) was measured with ultrasonic crystals. Responses to the volatile anesthetics were assessed under control conditions, during intracoronary infusion of the KATP channel inhibitor glibenclamide (100 micrograms/min), and after cessation of glibenclamide (recovery). The effectiveness of glibenclamide was verified from inhibition of coronary vasodilator responses to the KATP channel opener cromakalim without effect on those to the KATP channel-independent vasodilators, sodium nitroprusside and acetylcholine. Results Under control conditions, the volatile anesthetics caused pronounced increases in CBF (isoflurane > halothane = enflurane), and decreases in SS (enflurane > halothane = isoflurane). Glibenclamide blunted significantly (and reversibly) the increases in CBF, but it had no effect on the decreases in SS. Conclusions The KATP channels play an important role in coronary vasodilation but apparently are not involved in cardiac depression caused by halothane, isoflurane, and enflurane in canine hearts in situ.
Related Links	https://pubs.asahq.org/anesthesiology/article-pdf/86/2/448/377025/0000542-199702000-00020.pdf
Ending Page	458
Page Count	11
Starting Page	448
ISSN	00033022
e-ISSN	15281175
DOI	10.1097/00000542-199702000-00020
Journal	Anesthesiology
Issue Number	2
Volume Number	86
Language	English
Publisher	Ovid Technologies (Wolters Kluwer Health)
Publisher Date	1997-02-01
Access Restriction	Open
Subject Keyword	Journal: Anesthesiology
Content Type	Text
Resource Type	Article
Subject	Anesthesiology and Pain Medicine