Biomagnetic investigation of injury currents in rabbit intestinal smooth muscle during mesenteric ischemia and reperfusion.
A noninvasive, sensitive, and specific method of detecting mesenteric ischemia would be of great use in reducing the morbidity and mortality with which it is associated. Acute lesions in polarized electrically coupled tissues lead to injury currents driven by the transmembrane resting potential gradient. These injury currents are an effective indicator of pathophysiology. The presence of near-DC injury currents in rabbit intestinal smooth muscle has already been demonstrated using a Superconducting quantum interference device (SQUID), and the aim of this study was to evaluate the effect of arterial reperfusion upon these currents. We exteriorized the small bowel of 14 New Zealand white rabbits and placed a remotely operated vascular occluder around the distal most artery supplying a 3-in segment of the jejunum. Experiments were conducted in three groups, i.e., control (n=3), ischemia (n=6), and reperfusion following ischemia (n=5). The subject's position was modulated in and out of the biological field detection range of a SQUID magnetometer using a lift constructed of nonmagnetic material. The changes in magnetic field amplitude were 9.3 and 31.01% for the control and ischemia groups, respectively. The reperfusion group first exhibited a decrease of 17.35% from the pre-ischemic to the ischemic period, followed by an increase of 13.88% of the ischemic value after reestablishing perfusion. In conclusion, injury currents in GI smooth muscle that appear during ischemia are reduced to near-pre-ischemic levels during reperfusion.
O'Mahony
Gavin D
GD
Department of Surgery, Vanderbilt University School of Medicine, D 5219 MCN, Nashville, Tennessee 37232, USA.
Gallucci
Michael R
MR
Córdova-Fraga
Teodoro
T
Berch
Barry
B
Richards
William O
WO
Bradshaw
L Alan
LA
D000818:Animals; D004574:Electromagnetic Fields; D004594:Electrophysiology; D007422:Intestines / Q000098:blood supply* / Q000503:physiopathology; D007511:Ischemia / Q000175:diagnosis*; D008643:Mesentery / Q000098:blood supply* / Q000503:physiopathology; D009130:Muscle, Smooth / Q000098:blood supply / Q000503:physiopathology; D011817:Rabbits; D015424:Reperfusion