Automated absorption image cytometry of electromagnetically exposed frog erythrocytes

Abstract

Frog erythrocytes dedifferentiate in vitro when exposed to a suitable electromagnetic field in a chemically potentiated microenvironment. These electrochemical stimuli are able to induce a chromatin decondensation, as previously shown by measuring the chromatin accessible sites for acridine orange intercalation by means of flow cytometry (acridine orange green fluorescence). Automated absorption image cytometry of Feulgen stained smeared erythrocytes has been performed to further elucidate the above processes. After measuring or computing the area A of the nucleus, which is related to its volume, the nucleic integrated optical density D, which is related to the DNA content, the average optical density DA = D/A, which is related to chromatin conformation, and the accessible chromatin sites SA = D213 All3, the following results have been obtained: (a) electromagnetically exposed cells progress to stages which correspond to values of D equal to those of controls, in the potentiating solution, whereas A increases, so that DA is smaller in exposed erythrocytes than in control ones, confirming that chromatin decondensation is occurring as an early dedifferentiation step. (b) By using the electromagnetic signal that is most effective in promoting dedifferentiation, erythrocytes further progress toward more advanced stages, which correspond to larger values of both D and A than in controls, ie., to larger DNA content. (c) In all cases, the histograms of SA are in agreement with those previously obtained by flow microfluorometry of chromatin conformation (acridine orange green fluorescence). Finally, flow microfluorometric measurements of acridine orange red fluorescence give an increase of RNA content for case (a), as compared with controls, and for case (b) as compared with (a). These results point out that frog erythrocytes can be electromagnetically reactivated, resuming both RNA and DNA syntheses after initial chromatin decondensation.Frog erythrocytes are nucleated cells that undergo morphologic changes when exposed to suitable electromagnetic (em) fields in a chemically potentiated microenvironment (I, 6, 12, 14).

Bone Morphogenic Protein--mRNA upregulation after exposure to low frequency electric field

“…This explains the good results obtained by the stimulation of hypertrophic non union of the tibia with a pre-existing fibrocartilage and the weak results obtained on fresh fractures [13,15,16]. In parallel to these earlier studies on bone tissue, a cytofluorometry analysis after cell exposure shows an increase in RNA production and modification of the DNA configuration [9,10,12].…”

Role of Membrane Potential in the Regulation of Cell Proliferation and Differentiation

“…This work [111][112][113][114][115] is largely pre-molecular, and it remains to be seen what ion transporters and mechanisms can be capitalized upon in order to de-differentiate somatic cells for biomedical applications.…”

Electrochemical and electrical aspects of low-frequency electromagnetic current induction in biological systems

“…ulates transcriptional events in a dipteran genetic model {Good-man, et al, 1983); inhibits isolated bone cell responses to parathyroid hormone (Luben, et al, 1982); modulates the rate of amphibian RBC response to trauma (with resultant DNA uncoiling) (Chiabrera, et al, 1979a(Chiabrera, et al, , 1979b(Chiabrera, et al, , 1980 of fracture healing in the rat Bassett, et al, 1982c) and of limb regeneration in the salamander (Smith and Pilla, 1981); has a direct and synergistic (with cytotozic and immunomodulating chemotherapy) effect on survival time of mice with B-16 melanoma, Ridgeway osteogenic sarcoma, and spontaneous C3H mammary adenocarcinoma {Norton, et al, 1980{Norton, et al, , 1982 and has been successfully employed clinically for nonunions and pseudarthroses of bone (Bassett, et al, 1977, 1978, 1979, 1981a, 1981b, 1982a, 1982b, Sedel, et al, 1981Muller and Spaas, 1980;Hinsenkamp, 1982;Kort, et al, 1982). Radiofrequency modulated at low frequencies {1000 Hz) has been reported to affect Ca ++ uptake in isolated cerebral tissue (Bawin, et al, 1975(Bawin, et al, , 1978Blackman, et al, 1980) and learning ability in primates (Gavalas, et al, 1970).…”