Gorban E. N., Drevitskaia T. I., Topolnikova N. V., Mankovskaia I. N. mRNA expression of HIF-1α and HIF-3α in heart tissue of adult and old rats after interval hypoxic training and irradiation

Problems of Aging and Development, 2015, vol. 24, № 1.- P. 3-13.

mRNA expression of HIF-1α and HIF-3α in heart tissue of adult and old rats after interval hypoxic training and irradiation

E. N. Gorban, T. I. Drevitskaia*, N. V. Topolnikova, I. N. Mankovskaia*

State Institution "D .F. Chebotarev Institute of Gerontology NAMS Ukraine", 04114 Kyiv
*A. A. Bogomolets Institute of Physiology NAS Ukraine, 01601 Kyiv

Investigated was the effect of intermittent hypoxic training (IHT — breathing of air mixture comprising about 12 % O2 for 2 hours daily, 5 days per week for 2 weeks), prior to a single X-ray irradiation in sublethal dose (5 Gy) on changes of subunit mRNA expression of the transcription factor HIF (HIF-1a and HIF-3a) in heart tissue of adult (8 mo) and old (24 mo) rats 17 days after irradiation. Under normoxia mRNA expression of HIF-1a and HIF-3a subunits in cardiac tissue of old rats was found to be increased significantly (by 90 and 7 times, respectively) as compared to adults. The IHT led to a decrease of mRNA expression of both HIF subunits in heart tissue in animals of both age groups. More pronounced response of the HIF transcription factor was noted in adult vs. old rats 17 days after irradiation; this can be accounted for by diversely directional changes in the level of mRNA expression of HIF-3α subunit and reduction of ratio HIF-3α/HIF-1α in cardiac tissue of irradiated adult animals. Pre-exposure to IHT leads to the opposite reaction of HIF transcription factor of irradiated animals depending on age: in adult rats — significantly activate it, in the old — significantly depressed. A significant reduction in the expression of HIF-1α mRNA in the heart tissues of old irradiated rats pre-exposed to IHT effect might be of significant positive value, because increase of HIF-1α concentration with age is one of the reasons for reducing the cell ability to generate energy.