Local mechanical oscillations of the cell surface within the range 0.2-30 Hz

This paper describes transverse oscillations, within the range 0.2-30 Hz, of the surface of different animal cells: human and frog erythrocytes, human lymphocytes and monocytes, cultured 3T6 fibroblasts, and rat cardiomyocytes. The minimal area of the cell surface which undergoes unidirectional transverse movement is equal to or less than 0.5 x 0.5 microns. The amplitude of the oscillations recorded on larger surface areas is lower than on the smaller ones because of the averaging of solitary oscillations. The oscillation amplitude is different in different cells. The highest amplitude is recorded in human erythrocytes (350-400 nm), the lowest one, in fibroblasts, lymphocytes and monocytes (20-30 nm). The oscillations of the human erythrocyte are suppressed on hypotonic swelling, after hardening of the cell membrane owing to adsorption at the surface of the impermeable dye Heliogen Blue, by treatment of the cell with 0.01% glutaraldehyde, by treatment with 0.5 mM 4-hydroxy-mercurybenzoate, and after crenation caused by 1-2 mM 2,4-dinitrophenol. The amplitude of the surface oscillations is decreased in spectrin deficient erythrocytes obtained from patients with hereditary spherocytosis, which indicates an essential role for spectrin in the rapid oscillations of the erythrocyte surface.