The effects of magnetic field and pterostilbene on renal ischemia and reperfusion

Ischemia reperfusion injury is one of the most important pathological mechanisms observed after organ trasnplantation nowadays. Therefore, the development of new therapeutic strategies to prevent ischemic injury has a scientific signficance. The application of magnetic field to prevent ischemic injury has been proposed as a new treatment strategy, however there have been contraversial results reported on the effects of magnetic field as being effective or uneffective on ischemic injury. This study aims to determine the therapeutic role of 50 Hz low frequency magnetic field application and the administration of pterostilbene together with magnetic field application on kidney tissues of ischemia reperfusion rat model. In the study, renal ischemia reperfusion injury model was established by clamping the renal arteries for 20 minutes, then the kidneys were reperfused for 24 hours and the rats were projected to two different treatments. The first treatment group was subjected to 50 Hz low frequency magnetic field application and the rats in the second group received a 10 mg/kg dose of pterostilbene injection together with magnetic field application for 5 consecutive days. After 5 days, the kidneys were dissected and homogenised, the homogenate was analyzed by Fourier transform infrared (FTIR) spectroscopy. The results revealed that ischemia-reperfusion injury caused a decrease in lipid and protein amount, lipid/protein ratio, a decrease in the level of unsaturated lipids and unsaturated/saturated lipid ratio, an increase in lipid peroxidation in components of rat kidneys. Moreover, ischemia-reperfusion injury led to an alteration in the structure of lipids and proteins and a higher content of long chained lipids were observed in kidneys of ischemia-reperfusion group. Both treatments, but more precisely pterostilbene treatment together with magnetic field application was observed to be effective to restore these ischemia induced alterations. Although no significant changes were observed in the mebrane order, the increase in the bandwidth of the CH2 antisymmetric and symmetric strecthing bands revealed that membrane fluidity was increased in ischemia-reperfusion group, where both treatments were found to be effective to decrease the membrane fluidity. Although 50 Hz frequency magnetic field application was not sufficient to repair ischemia-induced alterations, pterostilbene treatment applied together with magnetic field successfully restored ischemia-induced changes in all of the investigated parameters. Key words: Renal ischemia reperfusion injury, low frequency magnetic field, antioxidant, pterostilbene, FTIR spectroscopy