[Effect of GBE50 on experimental arrhythmias].
OBJECTIVE
The action and mechanism of ginkgo leaf extract (EGB50) in fighting arrhythmia were studies.


METHODS
The animal model of arrhythmia was established by intravenous drip of aconitine and ouabain, and the standard microelectrode technique was used.


RESULTS
In Oua model, threshold doses of ouabain induced VP, VT, VF, CA were observed. GBE50 significantly increased threshold doses of ouabain. In Aco model, threshold doses of Aco induced VP, VT, VF, CA were observed, GBE50 significantly increased threshold doses of Aco. Effects of GBE50 on delayed afterdepolarization and triggered activity induced by ouabain in guinea pig papillary muscles DADs and TA were markedly suppressed by GBE50. The amplitude and duration of DADs were reduced by GBE50 (50 mg x L(-1)) from (13.25 +/- 2.38) mV and (198.38 +/- 53.62) ms to (4.04 +/- 1.44) mV and (57.00 +/- 18.62) ms, respectively, and the induced time of DADs was prolonged from (12.37 +/- 2.26) to (23.00 +/- 4.00) min. TA was reduced from 87.5% to 16.67% (P<0.05, P<0.01). GBE50 (2,10 mmol x L(-1)) had significant therapeutic effects on DADs. The amplitude and duration of DADs were reduced to (10.41 +/- 3.06) mV, (8.92 +/- 2.68) mV and (128.33 +/- 18.91) ms, 103.33 +/- 20.64 ms (P<0.05, P <0. 01 vs control).


CONCLUSIONS
GBE50 can fight arrhythmia following aconitine and ouabain. GBE50 has inhibitory effects on DADs and TA induced by ouabain and high Ca2+ in guinea pig papillary muscles.
Wang
Xingyu
X
Department of Physiology, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Zhang
Zhixiong
Z
Liu
Aihua
A
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D004195:Disease Models, Animal; D020441:Ginkgo biloba / Q000737:chemistry*; D006168:Guinea Pigs; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010936:Plant Extracts / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley
D010936:Plant Extracts