The effects of electroacupuncture on hypotension and the concentrations of intracellular free calcium ([ Ca

(2+)

]i) and free magnesium ([ Mg(2+)]

i) and free magnesium ([ Mg

(2+)

] i) in cardiac myocyte of rabbit were studied. The hemorrhagic hypotension was induced by losing blood from femoral artery of rabbit. [ Ca(2+) ]

i) in cardiac myocyte of rabbit were studied. The hemorrhagic hypotension was induced by losing blood from femoral artery of rabbit. [ Ca

(2+)

]i and [Mg(2+) ]

i and [Mg

(2+)

]i were determined by use of AR-CM-COM canon measurement system and the ionic probe fura-2 and fu- raptra. [ Ca(2+) ]

i were determined by use of AR-CM-COM canon measurement system and the ionic probe fura-2 and fu- raptra. [ Ca

(2+)

] i was significantly decreased

while [ Mg(2+)]

i was significantly decreased

while [ Mg

(2+)

] i was increased

and the ratio of [ Ca(2+) ]

i was increased

and the ratio of [ Ca

(2+)

] i/ [Mg(2+) ]

i/ [Mg

(2+)

] i was decreased as the blood pressure went down with losing blood. The blood pressure and [Ca(2+) ]

i was decreased as the blood pressure went down with losing blood. The blood pressure and [Ca

(2+)

] i of treatment group rabbits were significantly raised by electroacupuncturing the points of " Renzhong" and "Chengjiang"

and the ratio of [ Ca(2+) ]

i of treatment group rabbits were significantly raised by electroacupuncturing the points of " Renzhong" and "Chengjiang"

and the ratio of [ Ca

(2 +)

] i/ [ Mg(2 +) ]

i/ [ Mg

(2+)

] i was increased. The cardiac myocyte [ Ca(2+)]

i was increased. The cardiac myocyte [ Ca

(2+)

] i and [ Mg(2+)]

i and [ Mg

(2+)

] i of normal rabbits had no clear changes by electroacupuncture. It suggested that intracellular free calcium and magnesium ion in cardiac myocyte may play an important role in regulating blood pressure by acupuncture.