title: A new technique of in vivo synchrotron radiation coronary microangiography in the rat.
abstract: BACKGROUND
  Previously, in our laboratory, synchrotron radiation coronary microangiography (SRCA) using Langendorff-perfused rat hearts could visualize a coronary artery of 50 µm in diameter. However, in vivo rat SRCA poses the problem of compromised temporal resolution due to the rapid heart rate of rats.
  
  
  OBJECTIVE
  To establish a simple method of in vivo rat SRCA with bradycardia induced by intravenous injection of adenosine triphosphate disodium hydrate (ATP).
  
  
  METHODS
  SRCA was performed at the Photon Factory of the High Energy Accelerator Research Organization (Tsukuba, Japan). Eight male Wistar rats were anesthetized. A catheter for injecting the contrast material was inserted into the carotid artery. Temporary bradycardia was induced by an intravenous bolus injection of 5 mg of ATP, and SRCA was performed immediately thereafter.
  
  
  RESULTS
  After ATP administration, the average heart rate decreased from 388 to 73 beats per minute. As a result, we could detect a coronary artery as small as 45 µm in diameter.
  
  
  CONCLUSIONS
  Our SRCA system which has a high resolution of 9 µm per pixel could detect a coronary artery as small as 45 µm in diameter in the in vivo rat.
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan sakamotoh@md.tsukuba.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Faculty of Health Science, Tsukuba University of Technology, Tsukuba, Japan.
authors.forename: Shonosuke
authors.initials: S
authors.lastname: Matsushita
authors.affiliation: Photon Factory, High Energy Accelerator Research Organization, Tsukuba, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hyodo
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Tokunaga
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Fujio
authors.initials: F
authors.lastname: Sato
authors.affiliation: Department of Cardiovascular Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hiramatsu
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001919:Bradycardia / Q000139:chemically induced; D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography / Q000295:instrumentation / Q000379:methods*; D003331:Coronary Vessels / Q000033:anatomy & histology*; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017356:Synchrotrons
chemical_list: D003287:Contrast Media; C057937:iomeprol; D000255:Adenosine Triphosphate; D007479:Iopamidol
keywords: Cardiac; angiography; animal investigations; ischemia/infarction