[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 relaxation time T1 and T2 of the protons in the different-stage-diseased lenses of rats with diabetic cataract caused by the streptozotocin, and the results were put in comparison with those obtained from the control group, showing that after one month of medication the values of T1 and T2 in the cataractous lenses are greater than those gained from the control group. The variation, as time goes on, becomes greater and greater. T1 and T2 indicate the speed of the free induction decay (FID) signals, and the variation of the FID signals are in direct proportion to that of the proton content of the samples. This shows that an increase in T1 and T2 indicates an increase in the water content in the diseased lenses, and the changes in ratio of "bound" water to free water. Such changes may be explained that the space for "bound" water is occupied by some other macromolecules, causing the alteration of the macromolecular structure, and consequently the aggregation of protein and the degeneration or dehydration or dehydration of the membrane occur, which may give rise to another scattering centre. So the scattering of the lens increases and its transparency decreases. This result is in agreement with some reports in the medical literature. As T1 and T2 are quite different in the normal and pathological tissues, and the protons are the most extensive nucleus in all biological tissues, NMR is a very important method to determine the proton relaxation time in the biological tissue and to judge if it is normal or not.(ABSTRACT TRUNCATED AT 250 WORDS)