用核磁共振分析仪对大鼠糖尿病性白内障驰豫时间改变的研究

作者用核磁共振分析仪,测定链尿佐菌素所致大鼠糖尿病性白内障病变过程中,晶状体中质子的驰豫时间T_1、T_2的变化。结果表明,用药一月后,晶状体中质子T_1、T_2值逐渐增大,即晶状体含水量逐渐增多,在一定程度上反映了对组织中水含量的影响。作者认为可能因此导致蛋白聚集、细胞膜的退化或脱水收缩,从而形成新的散射中心,增加了光的散射,导致失明。

Study on the Variation of Relaxation Time in Diabetic Cataractous Lenses of Rats by Using NMRA

Nuclear magnetic resonance analysis(NMRA)was used to measure the relaxa-tion time T, and T_2, of the protons in thedifferent-stage-diseased lenses of rats withdiabetic cataract caused by the streptozoto-cin, and the results were put in compari-son with those obtained from the controlgroup, showing that after one month ofmedication the values of T_1, and T_2 in thecataractous lenses are greater than thosegained from the control group. The varia-tion, as time goes on, becomes greaterand greater. T_1 and T_2, indicate the speedof the free induction decay (FID) signals,and the variation of the FID signals arein direct proportion to that of the protoncontent of the samples. Tins shows thatan increase in T_1 and T_2 indicates an in-crease in the water content in the diseasedlenses, and the changes in ratio of"bound" water to free water. Suchchanges may be explained that the spacefor "bound" water is occupied by some othermacromolecules, causing the alteration ofthe macromolecular structure, and conse-quently the aggregation of protein and thedegeneration or dehydration or dehy-dration of the membrane occur,which maygive rise to another scattering centre. Sothe scattering of the lens increases and itstransparency decreases. Tnis result is inagreement with some reports in the me-dical literature. As T_1 and T_2, are quitedifferent in the normal and pathologicaltissues, and the protons are the mostextensive nucleus in all biological tissues,NMR is a very important method to de-termine the proton relaxation time in thebiological tissue and to judge if it is normalor not. Besides, T_1, and T_2 may serve as oneof the indicators in diagnosing the diseaseand evaluating the curative effect of themedicine.