[In vitro evaluation of prostaglandin I2 analogue on hypothermic injury to immature myocytes].

We evaluated the functional and biochemical effects of prostaglandin I2 analogue (PGI-A) on cardiac myocytes incubated under hypothermic conditions. Myocytes were isolated from neonatal rat ventricles and cultured for 4 days. Then, myocytes (12.5 x 10(5) myocytes/flask) were incubated at 4 degrees C for 24 hrs in media with PGI-A as follows; O M PGI-A (group C: control), 10(-9) M (group P1), 10(-8) M (group P2), 10(-7) M (group P3), 10(-6) M (group P4). 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 P2 showed significantly increased recovery compared to the control (P2: 47.9, p < 0.025, C:18.1 percent of control; ie, beating rate prior to hypothermic incubation). The release of CPK and LDH was significantly suppressed in group P2 compared to the control (P2:57.7, p < 0.05, 275.1, p < 0.025; C:96.8 mIU/flask, 439.6 mIU/flask, respectively). In conclusion, prostaglandin I2 has direct cytoprotective characteristics for immature myocytes that may be suitable for cardiac preservation.