Albertini G, Fanelli E, Guidoni L, Ianzini F, Mariani P, Masella R, Rustichelli F, Viti V
Int J Radiat Biol Relat Stud Phys Chem Med. 1987 Jul;52(1):145-56. doi: 10.1080/09553008714551571.
An investigation of the structural and thermodynamical modifications induced by gamma-irradiation in model membranes is reported. Differential scanning calorimetry and X-ray diffraction were used to study the different phases and associated transitions of distearoylphosphatidylcholine multilamellar liposomes after 60Co gamma-irradiation. Changes were observed in the shape of the calorimetric peaks and in the corresponding phase transition temperatures. In particular a shoulder was observed at about 20 kGy. The three phases characteristic of lecithins with identical acyl chains were detected also for the highest radiation dose. The formation of lysolecithin and stearic acid upon phospholipid degradation was observed. The lysolecithin concentration increases as a function of irradiation dose, until a saturation value is reached at 40 kGy. These results correlate quite well with those obtained for interlayer and interchain distances and for the width of the main phase transition calorimetric peak. At the highest dose (approximately equal to 80 kGy) cross-linked adjacent radicals and other molecular species are also formed. Appreciable differences, and some similarities, in the behaviour of DSPC and DPPC liposomes under gamma-irradiation were observed.
本文报道了对γ射线辐照模型膜所引起的结构和热力学变化的研究。采用差示扫描量热法和X射线衍射法，研究了经⁶⁰Co γ射线辐照后的二硬脂酰磷脂酰胆碱多层脂质体的不同相态及相关转变。观察到量热峰形状和相应相变温度的变化。特别是在约20 kGy处观察到一个肩峰。对于最高辐射剂量，也检测到了具有相同酰基链的卵磷脂的三个特征相。观察到磷脂降解时溶血卵磷脂和硬脂酸的形成。溶血卵磷脂浓度随辐照剂量增加而增加，直至在40 kGy时达到饱和值。这些结果与层间和链间距离以及主相变热峰宽度的结果相当吻合。在最高剂量（约80 kGy）时，还形成了交联的相邻自由基和其他分子物种。观察到DSPC和DPPC脂质体在γ射线辐照下行为的明显差异和一些相似之处。
