The Effect of Polyscias filicifolia Bailey Biomass Tincture on the Protein Synthesis Process in the Heterogeneous System From the Isolated Pig Heart

Background and Objective. An insufficient supply of oxygen to the heart influences the process of protein synthesis. The aim of this study was to determine the effect of the Polyscias filicifolia Bailey biomass tincture on the protein synthesis process in a heterogeneous translation system from the isolated pig heart. Materials and Methods. The effect of anoxia was evaluated after 20- and 90-minute anoxia. With the aim to determine the effect of Polyscias, the pig hearts were perfused with a buffer containing the Polyscias filicifolia Bailey biomass tincture. To determine the rate and the level of translation, the incorporation of [14C]-leucine into translational products in a cell-free system was measured. Results. The protein synthesis level decreased by 23%–42% when the translation system containing cytosol from the anoxic heart was used. When the translation system containing a ribosomal fraction after 20-minutes anoxia was used, the protein synthesis level was the same as in the control. In the case of 90-minute anoxia, it decreased by 16%. The protein synthesis rate and the level in the translation system containing cytosol from the heart after 20-minute anoxic perfusion with the buffer containing Polyscias was the same as in the control. Conclusions. A decrease in the protein synthesis rate and the level after 20-minute anoxia was determined by changes in cytosol. On the other hand, 90-minute anoxia caused changes in cytosol and the ribosomal fraction. The Polyscias filicifolia Bailey biomass tincture restored the protein synthesis process acting on the components of the translation system in cytosol and the ribosomal fraction.

Effect of anoxia and Polyscias filicifolia Bailey biomass tincture on the activity of tRNA and aminoacyl-tRNA synthetases in isolated pig heart

Objective. The aim of this study was to investigate effect of anoxia and Polyscias filicifolia Bailey biomass tincture on the activities of different tRNA and aminoacyl-tRNA synthetases in isolated pig heart. Material and methods. The isolated pig heart was perfused according to the modified method of Langendorf, using an artificial blood circulation apparatus. Anoxia 20 min in duration was performed by perfusion of isolated heart with Krebs-Henseleit bicarbonate buffer saturated with gas mixture (95% N2 and 5% CO2). Control heart was perfused with the same buffer saturated with gas mixture (95% O2 and 5% CO2). Effect of Polyscias filicifolia Bailey biomass tincture was evaluated by perfusion of isolated heart with a buffer containing tincture. Total tRNA and aminoacyl-tRNA synthetases were isolated from pig heart. Activities of tRNA and aminoacyltRNA synthetases were measured by the aminoacylation reaction using C14-amino acids. Results. Anoxia 20 min in duration has caused a decrease in the acceptor activity of tRNA and increase in the activities of aminacyl-tRNA synthetases. Polyscias filicifolia Bailey tincture did not affect the acceptor activity of tRNA and activities aminacyl-tRNA synthetases. After 20-min anoxic perfusion with the buffer containing Polyscias filicifolia Bailey biomass tincture, the acceptor activities of tRNA increased to the control value and activities of aminacyl-tRNA synthetases reached the control value. Conclusions. The acceptor activity of tRNA from isolated pig heart decreased and activities of aminacyl-tRNA synthetases increased under anoxia. Perfusion with buffer containing tincture of Polyscias filicifolia Bailey biomass restored acceptor activities of tRNA and activities of aminacyl-tRNA synthetases.

Transmembrane gradients of free Na+ in isolated heart mitochondria estimated using a fluorescent probe

The concentration of free Na+ in the matrix of isolated pig heart mitochondria has been monitored using the fluorescent probe sodium-binding benzofuran isophthalate (SBFI) developed by Minta and Tsien (J. Biol. Chem. 264: 19449-19457, 1989). SBFI was sequestered in the matrix by hydrolysis of the permeant acetoxymethyl ester. The sequestered probe showed altered quantum efficiency and excitation spectra in the presence and absence of Na+ when compared with SBFI free acid in solution. Fluorescence was calibrated in situ by using ionophores to equilibrate matrix [Na+] with external [Na+]. SBFI fluorescence showed that matrix [Na+] increased linearly as external [Na+] was increased to 95 mM in the presence or absence of respiration. Respiring mitochondria maintained a Na+ gradient (Na+ out greater than Na+in) of approximately 8.0. The corresponding gradient in nonrespiring mitochondria was approximately 2.0. The Na+ gradient was nearly equivalent to the H+ gradient in the presence or absence of respiration. The uptake of Pi by respiring mitochondria decreased matrix pH and increased matrix [Na+]. It is concluded that isolated mitochondria maintain a Na+ gradient across the inner membrane as a result of the activity of the endogenous Na(+)-H+ antiport.