| Heroin [Diacetylmorphine] is a high addictive diacetyl compound from a main component of opium alkaloid that was dried from the juice of the immature Papaver. In recent years, the amount of drug-abuse people in China is an increasing tendency. The most common Orphan drug is Heroin, as the most addictive and dangerous. According to recently report, there were 65000 cases of drug crime unearthed in 1999 and 5.364 tons of heroin, 1.193 tons of opium, 16.059 tons of Methamphetamine, as well as some cocaine, MDMA, Marijuana, were captured. The amounts of the unearthed cases and captured drug rised 2.4% and 33.6% respectively.The drug-abuses registered by police were 14800 in 1991, 52000 in 1995,and 68100 in 1999. The supposed true amount numbers should be 8-10 times more.In 1999, the numbers of the drug-abuse is 0.54%. of the whole population. Among the drug-abuses, 79.2% were yonger than 35 years old. Drug-abuse has becomed a serious problem for social stability, economic prosperity and people's health, which causes public concern by gorverment and more and more researchers.Numerous studies have reported that heroin seriouslyimpairs people'shealth, and some studies showed the levels of microelement, such as Zn,Ca,Cu,Mg,Fe in heroin-dependents is obviously deficient compared with in normal population. The long time taking in heroin can lead to nervous system symptoms and evoke asthma Long time drug-abuse can also cause various kinds of diseases, such as sexual inadequency, toxic encephalopathy, cardiovascular disease, acute renal failure, and even cause death.Although there are numerous studies about the toxicity of heroin and its hazard, the main objections usually focus on cell or biochemistry levels, rather than molecul levels and themechanism of the toxicity of heroin has not been found so far. Since 1980s, with the application of molecular biology in toxicology and the development of detection technology, more and more studies have aimed to genetoxicity of heroin-dependents. Some studies found that the rates of drug abuses lymphocyte micronucleus is higher than healthy people.In addition, the study about neur cell of heroin-addict rat were proved to exist apoptosis, but the mechanism was not found. Another study proved that the rates of SCE in drug abuse is higher than in healthy people. At present, a lot of researchs have focused on the relationship between the behavior of heroin-dependent and the polymorphism of the DRD2 gene. But the result had not been generally acknowledged.Therefore, we designed a molecular epidemiological study to investigate the genetic toxicity of heroin and its mechanism by comet assay, FCM , DNA ladder PCR- RFLP. This study is supposed to provide evidence to screening and health protection for exposured population, and achieve the aim of protecting people's health and decreasing the rates of drug-abuse. 1 -. Objects and Methods(1) . Objects 123 exposed to heroin-dependent were randomly selected from the center of drug-admonish in Hubei province as the drug-abuse group and 79 normal and non-drug-abuse people as the non-exposure group.(2). Methods Lymphocyte cells of them were obtained from the blood of the subjects. The DNA damage was detected by comet assay. The subjects and the lymphocyte cells were the same as the former. Extracting DNA and detecting the degree of cell apoptosis by FCM and DNA ladder. The selection of subjects, collection of lymphocyte cells and the extraction of DNA were the same as the former. The gene polymorphism was analyzed by PCR-RFLP. 2.. Results(1) The results showed that the rate of DNA tail of the drug-abuse group was 10.03%, which was higher significantly than that of the non-exposure group (1.26%) . The similar results were showed in the length of DNA tail (PO.01) . The time limit of drug-abuse and the rate of DNA tail have the significant relationship of time-effect (r= 0.683, P<0.05 ) . And the multiple non-condition logistic result showed that the frequency of DNA damage in the drug-abuse group was higher significantly than that of the non-exposure group (PO.05) .(2 ) The FCM results showed that the rate of apoptosis of the drug-abuse group was 28.93 % %, which was higher significantly than that of the non-exposure group (1.31%) (P<0.01) . The time limit of drug-abuse and the rate of apoptosis have the significant relationship of time-effect. And the multiple non-condition logistic result showed that the frequency of the rate of apoptosis in the drug-abuse group was higher significantly than that of the non-exposure group ( PO.05 ) . The DNA ladder results showed that the drug-abuse group has significant ladder step though electrophoresis agarose gel, and the longer time of drug-abuse, the more obvious of ladder step, the coincidence of the two results.(3) The results showed that the distribution frequency of Dopamine D2 receptor Taq I A gene that has three kinds of gene polymorphism in the exposure group, which was higher significantly than that of the non-exposure group (/*<0.01). No significant difference was found for the Taq I B gene between the exposure and the non-exposure group. The time limit of drug-abuse and the distribution frequency of A2/A2 gene have the positive correlation relationship, the longer time of drug-abuse, the higher of the frequency of A2/A2 gene. The results of multiple non-condition logistic result showed that the frequency of the A2/A2 gene in the drug-abuse group was higher significantly than that of the non-exposure group (P<0.05) .3, Conclusion(1) Long-term exposure to heroin-dependent may induce DNA damage, and the longer of the time of drug-abuse, the more serious of damage.(2) Long-term exposure to heroin-dependent may induce the apoptosis of the lymphocyte cells, and the longer of the time of drug-abuse, the more significant of apoptosis.(3) There are positive associations between the frequency of the A2/A2 gene of DRD2 receptor Taq I A and heroin-dependent. But there aren't enough evidences to proof the association between the distribution frequency of Dopamine D2 receptor Taq I B genethat has three kinds of gene polymorphism and heroin-dependent. 4^ DiscussionThe results of above three chapters showed: 1) DNA damage was found by comet assay; 2 ) cell apoptosis was found by FCM and DNA ladder; 3 ) the association was found between heroin-dependent and the frequency of the A2/A2 gene of DRD2 receptor Taq I A by PCR-RFLP, but we can't conclude that there are no association between heroin-dependent and the frequency of the B2/B2 gene of DRD2 receptor Taq IB. In a word, the result of genetic toxicity testing array indicates that exposure to heroin-dependent can induce DNA damage. That is, exposure to heroin-dependent is genotixic. Its mechanism probably includes free radicals, covalent combination and calcium homeostasis imbalance theories. Therefore, it is important to conduct long-term molecular epidemiological studies on the drug-abuse who exposed to heroin-dependent, and and achieve the aim of protection of the heath of people and decrease the rate of drug-abuse. |
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