Author(s)

Anna Nikoghosyan, Lilia Narinyan, Armenuhi Heqimyan, Sinerik Ayrapetyan^*

Life Sciences International Postgraduate Educational Center, UNESCO Chair in Life Sciences, Yerevan, Armenia.

Previously we have shown that nM ouabain-induced activation of cAMP-dependent Na/Ca exchange in reverse (R) mode in cell membrane has age-dependent weakening hydration effect on heart muscle and brain tissues and such Na/Ca exchange is characterized by quantum mechanical sensitivity. As in biological experiments radioactive ⁴⁵Ca is used for the study of cold ⁴⁰Ca exchange in cells and organisms, in the present work, the age-dependent effect of physiological solution (PS) containing either ⁴⁰Ca or ⁴⁵Ca on tissue hydration in different experimental conditions was studied in order to evaluate the bioequivalence of these two forms of Ca. The obtained data indicate that the intraperitoneal injections of ⁴⁰Ca PS and 45Ca PS leading to activation of RNa/⁴⁰Ca and RNa/⁴⁵Ca exchanges, respectively, have different age-dependent effects on heart muscle and brain tissue hydration. As in myocyte membrane, the Na/Ca exchange is more expressed than in neuronal membrane, the age-dependent heart muscle hydration is more sensitive to quantum properties of Ca than brain tissue hydration. The [⁴⁵Ca]i, in contrary to [⁴⁰Ca]i, has age-dependent weakening and stabilizing effect on tissue hydration and makes the latter insensitive to ouabain. The obtained data bring us to a strong conclusion that RNa/Ca exchange has quantum mechanical properties and in biological experiments radioactive ⁴⁵Ca cannot be used for adequate estimation of the functional activity of ⁴⁰Ca ions in cells and organisms.

Rat, Brain, Heart Muscle, ⁴⁵Ca, Na/Ca Exchange, Ouabain

Nikoghosyan, A. , Narinyan, L. , Heqimyan, A. and Ayrapetyan, S. (2020) The Radioactive ⁴⁵Ca Cannot Be Used for Adequate Estimation of the Functional Activity of ⁴⁰Ca Ions in Cells and Organisms. Open Journal of Biophysics, 10, 13-26. doi: 10.4236/ojbiphy.2020.101002.