[Radiation activation of angiotensin-converting enzyme during low-dose irradiation]

Radiation activation of angiotensin-converting enzyme (respect to Cbz-Phe-His-Leu as substrate) was obtained at the gamma (137Cs, t(irr) = 10s-2h, D approximately 3 Gy)- and X (plasma foces source, t(irr) = 10(-9)s, Cu-filter, D approximately 2 x 10(-5) Gy)-irradiation. The inactivation of the horseradish peroxidase at the same X-irradiation dose (2 x 10(-5) Gy) took place. Based on the experimental data and on the mathematical model proposed by us we made a conclusion that the special points exist on the dose response curves. Besides, the deduction that an activation is a common process at radiation changes of the different enzymes follows from our model. The activation of tobacco peroxidase (in presence of Ca(2+)-cations and without them) and of recombinant horseradish peroxidase (in presence of H2O2) by gamma-irradiation was really observed (respect to guaiacol as substrate).