[Cytoprotective effects of nicorandil on immature myocytes under hypothermic conditions].
We evaluated the functional and biochemical effects of nicorandil on cardiac myocytes incubated under hypothermic conditions. Cardiac myocytes were isolated from neonatal rat ventricles and cultured for 4 days. Myocytes (12.5 x 10(5) myocytes/flask) were then incubated at 4 degrees C for 24 hrs in media with nicorandil as follows: O M  nicorandil (group C: control), 10(-5)M (group N 1), 5 x 10(-5)M (group N 2), 10(-4)M (group N 3). After hypothermic incubation, CPK and LDH were measured. The myocytes were then cultured for 24 hrs at 37 degrees C to evaluate the recovery of myocyte beating rate. For the beating rate, group N 3 showed a significantly increased recovery compared to the control (N 3: 44.2, p < 0.02, C: 24.6 percent of control; ie, beating rate prior to hypothermic incubation). The release of CPK and LDH was significantly suppressed in group N 3 compared to the control (N 3: 24.1, p < 0.005, 247.2, p < 0.01; C: 125.4 mIU/flask, 459.5 mIU/flask, respectively). Thus, nicorandil has cytoprotective effects on immature myocytes under hypothermic conditions.
Orita
H
H
Second Department of Surgery, Yamagata University School of Medicine, Japan.
Fukazawa
M
M
Inui
K
K
Hirooka
S
S
Uchino
H
H
Uchida
T
T
Shiono
T
T
Washio
M
M
D000818:Animals; D002478:Cells, Cultured; D015925:Cryopreservation; D003470:Culture Media; D009206:Myocardium / Q000166:cytology*; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D020108:Nicorandil; D051381:Rats
D003470:Culture Media; D009536:Niacinamide; D020108:Nicorandil