Timed dose-response relationship of depressive action of ouabain on toad heart contraction in vitro
Wang, M.Y.; Zhang, F.T.
Zhongguo Yao Li Xue Bao 14(6): 523-526
1993
ISSN/ISBN: 0253-9756 PMID: 8010050 Document Number: 408872
Timed dose-response relationship (TDRR) of depressive action of ouabain (Oua) 0.01 - 30 mmol cntdot L-1 on toad heart contraction in vitro was studied by simultaneous recordings of mechanical tension and electrocardiography. It was found that the inhibition of contraction tension, the latency, the half equilibrium time of depression, and the cardioplegia time (CPT) were all concentration-dependent (P lt 0.01). The EC-50 +- L-95 of Oua was 35 +- 8 mu-mol cntdot L-1, in which L-95 is the average 95% confidence limit. The TDRR data of latency or CPT were fitted to the hyperbolic 4-parameter model II weighted with the square of SE inversely, Y = 25.9492-7.2757 /(InX + 23. 5906)-6.2757 + 72. 7732 for latency and Y = 20637. 37/(Inx + 3. 0947)-3.5907 + 196. 7069 for CPT. It was concluded that the hyperbolic type of TDRR was present in Oua depressive action on the toad heart contraction in vitro.