Table 2.

Thresh-old and half-maximal concentration (IC50) of ouabain (OU) and marinobufagenin (MBG) triggered Na,K-ATPase and K⁺/⁸⁶Rb uptake inhibition.

Cell type	Tested CTS	Thresh-old, nM	Half-maximal effect, nM	References
Na,K-ATPase
c-kidney	OU	1	20	129
r-kidney	OU	5 × 103	105	130
m-kidney	OU	105	106	131
r-sarcolemma from aorta	OU	10	50	36
r-kidney medulla	OU	104	>105	132
r-intravascular nerve ending	OU	1	2.6	36
h-rings from mesenteric artery	OU	1	14	12
r-sarcolemma from left ventricle	OU	10	2.5 × 103	133
h-erythrocytes	MBG	1	70	134
r-sarcolemma from aorta	MBG	1	2.1	36
r-intravascular nerve ending	MBG	100	140	36
r-sarcolemma from left ventricle	MBG	1	5.5 × 103	133
r-kidney medulla	MBG	0.5	10	132
r-kidney medulla	MBG	0.1	50	120
h-sarcolemma from mesenteric artery	MBG	1	50–60	117,135
h-rings from mesenteric artery	MBG	1	50	136
h-sarcolemma from pulmonary artery	MBG	0.1	50	137
Sf-9 cells transfected withr-α1β1	OU		43,000	138
Sf-9 cells transfected withr-α2β1	OU		170	138
Sf-9 cells transfected withr-α1β1	OU		31	138
K+/86Rb uptake
h-erythrocytes	OU	1–2	50	139,140
r-erythrocytes	OU	>103	2 × 105	141
h-leukocytes	OU	0.1	0.56	142
c-renal epithelial cells	OU	>3	50	37
r-fetal brain	OU	<10	20	143
r-renal epithelial cells	OU	103	5 × 104	79
r-renal epithelial cells	OU	104	3 × 105	129
gp-carotid artery	OU	<1	10	144
c-renal epithelial cells	MBG	30	80	37

Abbreviations: c – canine; gp – guinea pig; h – human; m - mouse; r – rat.

Data obtained in rodents appear in italics.