Effect of cyclosporin on various metabolic processes in fungi

: Sensitivity of the representatives of Aspergillus and Piricularia to various concentrations of cyclosporine (in the submerged culture) was studied for choosing the test object for the subcellular investigation of the mechanism of the cyclosporine antifungal action. Changes in the main physiological and biochemical parameters of the fungal cells under the action of cyclosporine in concentrations of 10 to 80 micrograms per 1 ml of the medium were characterized. Low concentrations of cyclosporine (10 to 20 micrograms/ml) did not inhibit the growth of Aspergillus niger but induced stimulation of the growth processes. Only at a concentration of 80 micrograms/ml the inhibitory effect was observed. At the same time there was detected a dramatic stimulation of the culture respiration via the basic respiration chain. In the culture of Piricularia oryzae only inhibition of the culture growth even at the minimum concentration of cyclosporine (10 micrograms/ml) was recorded. Both the cyclosporine sensitive test objects i.e. A. niger and P. oryzae had an alternative cyanide resistant system of the electron transport. In the experiments with A. niger the cyclosporine effect on the synthesis of protein and RNA was revealed. The study provided data on the changes in the morphogenesis of the A. niger cells under the effect of cyclosporine.