ABSTRACT
Effects of low-dose gamma-irradiation (up to 1 R) upon UV absorption spectra of water dispersions of egg yolk lecithin (1:1) and samples of rat liver homogenate were studied. Clearly detectable changes could be observed in the 200-220 nm range already under dose loads of several mGy. Radiation sensitivity was shown to be essentially temperature dependent, being the highest at physiological temperatures.
Subject(s)
Cell Membrane/radiation effects , Membranes, Artificial , Phosphatidylcholines/radiation effects , Animals , Cell Membrane/chemistry , Gamma Rays , Phosphatidylcholines/chemistry , Radiation Tolerance , Rats , Spectrophotometry, Ultraviolet , TemperatureABSTRACT
Thermogravimetric studies of egg yolk lecithin water dispersion were carried out under conditions similar to those previously used in DSC studies of model biomembranes. For comparison, water dispersion of Na-DNA from calf thymus was studied in a parallel series. In both cases several distinct states of associated water were observed. The biomolecule/water stoichiometry obtained is compared with respective literature data.
Subject(s)
DNA/analysis , Egg Yolk/chemistry , Phosphatidylcholines/analysis , Thermogravimetry , Water/chemistry , SolubilityABSTRACT
A novel method of DSC studies of biomembranes has been proposed, making it possible to investigate the influence of ionizing radiations upon the structure of water dispersions of phospholipids and phospholipid-based systems of natural origin, e.g., rat liver homogenates and erythrocyte ghosts. It is shown that in certain concentration range of the bonded water thermograms obtained are reproducible during heating and cooling cycles and can give information about phase state, supramolecular ordering and radiation sensitivity of the systems under consideration.
