Mechanisms of analgesic action of Gln49-PLA(2) from Gloydius ussurensis snake venom.
Gln49-PLA(2) is a phospholipase A(2) isolated from the Gloydius ussurensis snake venom. In this paper, we studied its effect on the function of neural conduction. Electrophysiological studies demonstrated that Gln49-PLA(2) reduced the amplitude of the action potential and the velocity of nerve conduction on isolated mouse sciatic nerve. Patch clamp recordings confirmed that Gln49-PLA(2) significantly decreased neural excitability by the potentiation of sodium channels and the blockade of potassium channels in nerve terminal. In freshly isolated hippocampal pyramidal neurons, 54.25% of potassium current was inhibited by 20 microg/ml Gln49-PLA(2). However, sodium current was potentiated by 158.99% under the same condition. These findings demonstrate that the effect of Gln49-PLA(2) on ion channels is the main mechanism of analgesic action.
Zhang
Yu
Y
Department of Bioscience & Biotechnology, Dalian University of Technology, Dalian 116024, People's Republic of China.
Jiang
Bo
B
Li
Wenli
W
Zhou
Cheng
C
Ji
Fangling
F
Xie
Qun
Q
Sun
Xiaojiao
X
An
Lijia
L
Bao
Yongming
Y
D000200:Action Potentials / Q000187:drug effects; D000700:Analgesics / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D006624:Hippocampus / Q000166:cytology; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D051379:Mice; D009431:Neural Conduction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D054467:Phospholipases A2 / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D012584:Sciatic Nerve / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D012910:Snake Venoms / Q000201:enzymology* / Q000494:pharmacology; D017819:Viperidae
D000700:Analgesics; D007473:Ion Channels; D012910:Snake Venoms; D054467:Phospholipases A2