[Changes in cellular microfilaments in viral infection].

The effect of disorders in actin microfilament polymerization by cytochalasin B (CB) on the development of cytopathic changes was studied in two models. CB in concentrations of 0.1-1.0 microgram/ml enhanced 3-5-fold the formation of symplasts in a line of kidney cells from green monkey 4647 infected with carnivore distemper virus and inhibited this process in higher concentrations (2.5-5.0 micrograms/ml). The addition of CB in concentrations 5-10 micrograms/ml into the medium of a line of Chinese striped hamster cells infected with Sindbis virus led to disorders in the permeability of plasmolemma and destruction of cells although virus reproduction and production of virus antigens remained uninvolved. The above results not only demonstrate the role of actin microfilaments in the development of cytopathic lesions caused by paramyxo- and alphaviruses but also allow the assessment of separate stages of these processes.