Effects of tetrandrine on action potentials and afterhyperpolarization potentials in toad dorsal root ganglia
Zeng, W.Z.; Liu, T.P.
Zhongguo Yao Li Xue Bao 13(5): 420-423
1992
ISSN/ISBN: 0253-9756 PMID: 1300044 Document Number: 399796
Intracellular recordings were obtained from the cytosome of type A primary afferents in the isolated toad dorsal root ganglia (DRG) preparations. Bath application of Ca2+ 8.0 mmol.L-1 led to prolong action potential duration of repolarization 100% (APD100) by 23%, afterhyperpolarization potential duration of depolarization 50% (AHPD50) by 46%, and increase afterhyperpolarization potential amplitude (AHPA) by 40%. Verapamil 3 mumol.L-1 shortened the APD100 by 7% and the AHPD50 by 13%, and reduced the AHPA by 17%. The effects of Tet 3-100 mumol.L-1 consisted of APD and AHPD50 shortening and AHPA reduction in concentration-dependent manner. Tet 100 mumol.L-1, APD100 was shortened by 16%, AHPD50 by 18%, and AHPA was reduced by 20%. The results suggested that the effects of Tet may be related to its Ca2+ channel blockade in DRG.