[Effects of dicarboxyethenylgermanium sesquioxide on electrical and mechanical activity in isolated guinea pig and rabbit heart].
The effects of dicarboxyethenylgermanium sesquioxide (DCG) on electrical and mechanical activity in isolated guinea pig papillary muscles and rabbit sinus node were studied by intracellular capillary glass electrode. The effects of DCG on slow action potential and contractile force (Fc) of preparations in which the fast Na+ channels were inactive by partial depolarization by increasing the concentration of K+ 25.4 mmol/L were observed. DCG (0.5 mol/L) increased Vmax and APA of fast action potential of guinea pig papillary muscles, but its Fc decreased from 105 +/- 12% of control to 80 +/- 16%. DCG prolonged the spontaneous cycle length (SCL) and APD90 of rabbit sinus node, but the slope of phase 4(SP4) was lowered. The functional refractory period (FRP) of rabbit left atria was determined by the paired stimulus method. In experiments involving one drug, the drug was added until equilibrium had been reached. It has been demonstrated by experiments that the administration of DCG resulted in an increase of atrial FRP. These findings suggest that the Ca2+ inward currents and the K+ outward current may be inhibited by DCG.
Ma
F J
FJ
Zhao
G S
GS
Li
X G
XG
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D005260:Female; D005857:Germanium; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009942:Organometallic Compounds / Q000494:pharmacology*; D010210:Papillary Muscles / Q000502:physiology; D011422:Propionates; D011817:Rabbits; D012849:Sinoatrial Node / Q000502:physiology
D009942:Organometallic Compounds; D011422:Propionates; D005857:Germanium; C066750:propagermanium