We have investigated the binding of n-toluenesulfonate-4-(n-dimethylaminostyrene)-1-methylpyridinium (DSM) to human and animal erythrocyte membrane. It was discovered the spectral characteristics and binding parameters of the probes differ in the norm and in various pathologies, at changing adrenoreactivity of the animal organism. It is concluded that the probe can be used to assess the changes in membrane properties and in the beta-adrenoreceptive function of both the erythrocytes and the organism as a whole.