Antihypertension Induced by Tanshinone IIA Isolated from the Roots of Salvia miltiorrhiza

Table 2

Effect of K⁺ channel blockers on the inhibition of tanshinone IIA-induced changes in [Ca²⁺]_𝑖 in A7r5 cells^a.

	[Ca^2+]𝑖 (nmol l^−1)
	Phenylephrine (10 nmol l^−1)		KCl (40 mmol l^−1)
	Vehicle	Tanshinone IIA (10 μmol l^−1)	Vehicle	Tanshinone IIA (10 μmol l^−1)
Basal	440.2±29.3^##	256.4±32.5^∗∗	423.7±32.4^##	246.5±27.6^∗∗
Glibenclamide (μmol l^−1)
1	451.3±35.7^##	292.1±27.6^∗∗	429.7±37.2^##	283.5±29.8^∗∗
10	458.7±30.2^##	371.6±23.7^∗,##	432.6±33.2^##	386.2±31.5^∗,##
100	462.6±32.3^##	405.3±31.4^##	440.5±34.6^##	418.6±28.6^##
Apamin (0.1 μmol l^−1)	459.5±39.2^##	264.8±28.4^∗∗	439.8±29.7^##	254.3±27.2^∗∗
Charybdotoxin (0.1 μmol l^−1)	460.3±34.2^##	257.2±26.7^∗∗	441.2±31.4^##	252.9±30.6^∗∗
Barium chloride (10 μmol l^−1)	456.7±33.9^##	270.7±32.4^∗∗	436.5±28.6^##	261.7±25.9^∗∗
4-Aminopyridine (1 mmol l^−1)	462.5±30.1^##	262.3±34.1^∗∗	443.8±32.5^##	258.3±28.6^∗∗

^aData (mean ± SD) were obtained from six experiments. The [Ca²⁺]_𝑖 obtained from A7r5 cells without any treatment was 214.7 ± 34.2 nmol l⁻¹. Data from phenylephrine (10 nmol l⁻¹)- or KCl (40 mmol l⁻¹)-treated cells without K⁺ channel blockers treatment were served as basal level in each group. *𝑃<.05 and **𝑃<.01 versus basal level obtained from cells treated with the same volume of vehicle to dissolve testing K⁺ channel blockers in each group. ^#𝑃<.05 and ^##𝑃<.01 versus value from cells received tanshinone IIA treatment in the absence of K⁺ channel blockers in each group.