We studied the effects of lisinopril (Lis) and captopril (Cap), two an
giotensin-converting enzyme inhibitors, on calcium in ischemia/reperfu
sion and normal rat hearts. Ischemia/reperfusion hearts were subjected
to 15 min ischemia followed by 1 or 30 min reperfusion. Lis 0.1 mumol
. L-1 and Cap 200 mumol . L-1 decreased the concentration of calcium
in ischemia/reperfusion hearts (the content of calcium in reperfusion
1 min heart were reduced from 4.0 +/- 0.6 to 2. 7 +/- 0.5 and 3. 0 +/-
0. 9 mumol/g dry wt respectively). In cultured cell of neonatal rat h
eart, both drugs inhibited the uptake of Ca-45(2+). The activity of Na
+ , K+-ATPase prepared from rat heart was increased (activity increase
d from 15.7 +/- 2.3 in control group to 21.2 +/- 2.0 and 22.0 +/- 3.1
mumol/h mg protein in Lis and Cap groups, respectively). This calcium
lowering effects of Lis and Cap may be important in protecting the isc
hemia/reperfusion damage of myocardium.