Changes of fatty acid composition of brain synaptosomal phospholipids in isoflurane exposure rat]

We examined effects of inhalational anesthetic drug, isoflurane, on phospholipid and fatty acid in brain synaptosome. Wistar strain male rat was treated by inhalation of isoflurane. Rats were divided into 3 groups each 6 rats, one was 1 minimum alveolar concentration (MAC) exposure group, 1MAC group, and another was 2 times of MAC exposure group, 2MAC group, and the other was non exposure group, control group. The animals were kept in to box (0.343 m3) and the gas flow rate was set in 4 L/min by anesthetic instrument. After 60 minutes of exposure, rats were decapitated. Immediately, cerebrums were removed and fraction of synaptosome was sampled. In 2MAC group, C14:0 of phosphatidylcholine (PC) increased significantly as compared to the control group, but C16:1, C18:0, C18:2 and C20:3 decreased significantly. And also, C18:2 and C20:3 decreased significantly in 1MAC group. In terms of phosphatidylethanolamine(PE), C18:1 in 1MAC group, C14:0 and C16:1 in 2MAC group increased, but C20:3, C20:4 and C22:5 in 2MAC group decreased significantly as compared to the control group. Regarding phosphatidylserine + phosphatidylinositol, C14:0 in 2MAC group increased, but C22:5 decreased. In lysophosphatidylcholine, C12:0 and C14:0 in 2MAC group and C18:0, C20:4 in 1MAC group increased significantly, but C18:1 in 2MAC decreased. The changes of phospholipids and fatty acid in synaptosome were due to the metabolism of phospholipids of basic matrix and this was caused by effects of isoflurane on neural cellular membrane. The results indicated the suppression of membrane activity. Isoflurane has physiological activity on metabolism of phospholipid of cellular membrane. Thus, it has effects on neural cellular functions in brain.