SC4453

SC4453 is a digoxin analogue in which the lactone ring at C17β is replaced by a pyrazine ring. SC4453 is slightly inferior to digoxin in inhibiting (Na+ + K+)-ATPase, but shows similar sensitivity to potassium ions. The differences in the sensitivity of SC4453 to heart and brain tissue from different species are mainly due to differences in its dissociation rate from the receptor. These observations confirm the high sensitivity of the human heart to cardiac glycosides.

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