PMID- 11677764
OWN - NLM
STAT- MEDLINE
DCOM- 20051021
LR  - 20151119
IS  - 0366-6999 (Print)
IS  - 0366-6999 (Linking)
VI  - 114
IP  - 10
DP  - 2001 Oct
TI  - Effect of tetrandrine on cellular electrophysiology and calcium uptake of 
      myocardium in guinea pigs and dogs.
PG  - 1046-50
AB  - OBJECTIVE: To study the effects of tetrandrine, a Chinese herbal medicine, on the 
      action potential (AP), contraction as well as sarcoplasmic reticulum (SR) calcium 
      uptake of myocardium in guinea-pigs and dogs. METHODS: Changes in AP, dV/dt, peak 
      tension (PT) and dT/dt of myocardial cells were studied using the technique of 
      glass electrode. Changes of the calcium uptake rate by sarcoplasmic reticulum and 
      release of inorganic phosphate from sarcoplasmic reticulum were assessed with 
      biochemical techniques. RESULTS: Tetrandrine exerts a concentration-dependent and 
      frequency-dependent negative inotropic effect and shortens action potential 
      duration. Tetrandrine depresses both dT(E)/dt and dT(L)/dt as well as the tension 
      of myocardium, and reduces dV/dt and amplitude only in the slow action potential, 
      thus implying that tetrandrine blocks the slow calcium channel. In addition, 
      compared with thapsigargin, a specific inhibitor of Ca(2+)-ATPase on SR, 
      tetrandrine more apparently suppresses the contraction of the myocardium. 
      CONCLUSIONS: Tetrandrine is a wide-range calcium antagonist of plant origin. Not 
      only it blocks the voltage-operated calcium channels as other authors reported, 
      but also may play an important role in affecting the function of Ca(2+)-ATPase 
      and calcium release channels on SR. From this study, we also suggest that the 
      calcium channel appears to be more critical than SR for the contraction of 
      myocardium.
FAU - Guan, S
AU  - Guan S
AD  - Department of Geriatric Medicine, Union Hospital, Tongji Medical College of 
      Huazhong University of Science and Technology, Wuhan 430022, China.
FAU - Lynch, C 3rd
AU  - Lynch C 3rd
LA  - eng
PT  - Journal Article
PL  - China
TA  - Chin Med J (Engl)
JT  - Chinese medical journal
JID - 7513795
RN  - 0 (Alkaloids)
RN  - 0 (Benzylisoquinolines)
RN  - 0 (Phosphates)
RN  - 29EX23D5AJ (tetrandrine)
RN  - 67526-95-8 (Thapsigargin)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Action Potentials/drug effects
MH  - Alkaloids/*pharmacology
MH  - Animals
MH  - Benzylisoquinolines/*pharmacology
MH  - Calcium/*metabolism
MH  - Coronary Vessels/*metabolism
MH  - Dogs
MH  - Dose-Response Relationship, Drug
MH  - Female
MH  - Guinea Pigs
MH  - Male
MH  - Myocardial Contraction/*drug effects
MH  - Myocardium/*metabolism
MH  - Phosphates/metabolism
MH  - Sarcoplasmic Reticulum/metabolism
MH  - Thapsigargin/pharmacology
EDAT- 2001/10/27 10:00
MHDA- 2005/10/22 09:00
CRDT- 2001/10/27 10:00
PHST- 2001/10/27 10:00 [pubmed]
PHST- 2005/10/22 09:00 [medline]
PHST- 2001/10/27 10:00 [entrez]
PST - ppublish
SO  - Chin Med J (Engl). 2001 Oct;114(10):1046-50.