[Effects of ranitidine on ventricular refractory period and fibrillation threshold of normal and ischemic ventricle in rabbits].
Effects of ranitidine (Ran) on ventricular refractory period and fibrillation threshold of normal and ischemic ventricle were investigated in pentobarbitone anesthetized rabbits. In saline-treated rabbits, relative refractory period (RRP) and effective refractory period (ERP) were shortened from 132 +/- 24 to 126 +/- 25 ms (n = 10, P < 0.05) and from 118 +/- 22 to 108 +/- 27 ms (n = 10, P < 0.05) in boundary zone of ventricular ischemic regions, respectively. The ventricular fibrillation threshold (VFT) was decreased from 5.5 +/- 1.4 to 2.8 +/- 1.1 V (n = 10, P < 0.01) after coronary artery ligation (CAL). Ran (25 mg.kg-1, i.v.) not only prevented these changes, but also lengthened RRP from 123 +/- 14 to 136 +/- 10 ms (P < 0.05) and ERP from 111 +/- 16 to 126 +/- 12 ms (P < 0.05), and increased VFT from 4.7 +/- 0.8 to 7.4 +/- 1.8 V (P < 0.01) in normal ventricle. The results suggest that Ran may have anti-arrhythmic effects in rabbits.
Qiu
H Y
HY
Cardiovascular Disease Institute of He-nan Medical University, Zhengzhou, China.
Wei
T X
TX
Zhang
Y R
YR
Yan
X F
XF
Wei
J H
JH
D000818:Animals; D005260:Female; D008297:Male; D017202:Myocardial Ischemia / Q000150:complications / Q000503:physiopathology*; D011817:Rabbits; D011899:Ranitidine / Q000494:pharmacology* / Q000627:therapeutic use; D012032:Refractory Period, Electrophysiological / Q000187:drug effects*; D014693:Ventricular Fibrillation / Q000517:prevention & control*
D011899:Ranitidine