Investigation of Membrane Proteins in Rat Erythrocytes in Spontaneous Hypertension by Means of Spin-Label Technique

It has been suggested that alterations in cell membrane proteins may play a role in changes of erythrocyte membrane structure and function in hypertension. In order to characterize the structure of membrane proteins of erythrocytes from spontaneously hypertensive rats (SHR) the spin-label technique with a maleimide spin-label was used. A significant difference was observed in the characteristic electron-spin resonance (e.s.r.) spectrum of the label between samples from normotensive rats and SHR. The difference was eliminated and the spectrum significantly changed after treatment of the labelled membrane with EDTA followed by washing out the EDTA extracts, whereas the same treatment with EDTA without the following washing had no effect on the e.s.r. spectrum. It is concluded that the EDTA extracts different substances in the different rat groups. The spin-label technique is a useful method for distinguishing cell membrane properties in SHR and normotensive rats.