S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 13 No.4 (1972)
Ouabain이 Ca++-Troponin 상호작용에 미치는 영향
The effect of ouabain on Ca++-troponin interaction
- 정명희; 홍사악; 박찬웅
- Issue Date
- 서울대학교 의과대학
- Seoul J Med, Vol.13 No.4, pp. 261-267
- The possible mechanism of inotropic action of
cardiac glycosides(CG) have been sought with respects
to the cellular and intracellular mobi1izatiop of
But calcium, which plays a triggering role in
excitation-contraction coupling, acts upon the
contractile protein, esp. troponin. eventually
stimulates ATPase activity of actomyosin and induces
the muscular contraction.
Although many investigations were devoted to
search for the possible effects of CG on the
contractile protein, no conclusive evidence for a
direct interference of CG with the physicochemical
or enzymatic properties of the actomyosin is
Present study was made to observe the effect of
ouabain on the Catt-troponin interaction in the
superprecipitation of actomyosion. The results are summarized as follows.
1. The initiation of the superprecipitation of
natural actomyosin was delayed by adding EGTA
before the superprecipitation reaction.
This delayed initiation by EGT A was not affected
2. The addition of EGT A during the superprecipitation
caused the superprecipitation curve to be
declined nearly to the level before the reaction.
This clearing effect of EGT A on superprecipitation
was reversed by ouabain. which also accelerated curve
to reach the maximum more rapidly.
3. Above effect of ouabain showed the doseresponse
4. Di git onin did not show such effect as ouabain
5. Above effect of ouabain on the action of EGT A
during the reaction also obtained from the Perry
myosin B superprecipitation in the presence of
troponin and tropomyosin.
6. It is suggested that ouabain affects the troponincalcium
interaction and alters the binding property
of calcium to the troponin.