[Effect of hormones on the susceptibility of the swine cell line IB-RS-2 to foot-and-mouth disease virus].

The actions of hydrocortisone and insulin on the multiplication of foot-and-mouth disease virus were studied. The data obtained showed that the infectivity and the synthesis of the virus nucleic acid as evaluated through the plaque assay method and the kinetics of Uridine-3H incorporation were increased or decreased by hydrocortisone (2 x 10(-6) M). The induction of both effects seems to be related to the carbohydrate metabolism: when the maintenance medium contained glucose or glucose plus calf serum there was an inhibition on virus multiplication and no effect was observed in the absence of both serum and glucose. This was found both when the hormone was added to the cell culture 24 hours before infection as well as when it was added immediately or thirty minutes after virus adsorption. The possibility that these effects could be related to the synthesis of viral RNA-polimerase is discussed. Insulin (50 ng/ml) did not induce any effect on foot-and-mouth disease virus multiplication. However this hormone antagonized the action of hydrocortisone on the infectivity and on the synthesis of foot-and-mouth disease virus nucleic acid.