Salāmat-i kār-i Īrān (May 2020)
The effect of noise exposure on the level of sex hormones in male rats addicted to opium
Abstract
Background and Aim: Noise pollution was the most common environmental factor and widespread physical harmful agent in the workplaces which large numbers of workers were exposed in various sectors of industry, agriculture, mineral and so on. In the 21st century, exposure to noise is recognized as one of the threats to the health of the community. Hearing loss (temporary or permanent), increased blood pressure, sleep disturbances, lack of concentration, and increased human error can be attributed to exposure to noise.World Health Organization has identified noise as the second environmental stressor in the world. In Iran (As a developing country in the Middle East), more than 2 million workers are exposed to a noise level higher than 85 dB. Stress caused by noise can affect the level of sex hormones. A study by Nadri et al., It was found that exposure to 100 dBA continuous noise significantly reduced the level of sex hormones (testosterone, follicular stimulatory and luteinizing hormones). Addiction is one of the greatest problems of human societies which not only causes social and behavioral disorders, but also affects various aspects of physical health, imposes huge financial losses on individuals, families and society. Opium comes from opium poppy and consists of more than twenty alkaloids (combination of seventy compounds). Among the diverse varieties of narcotics, opium and heroin, they have the highest global consumption. The most commonly used drug opium is oral (swallowing) (49.5%) and inhalation (drainage) ((59%). For various reasons, such as having a common border with Afghanistan (as a producer of 90 percent of the worldchr('39')s opium), opium drug abuse among Iranian industrial workers has a relatively high prevalence. Some people believe that long-term use of low-dose opioids may prevent chronic illness (Such as cardiovascular disease) and prolong life. Addiction is a problem that has spread increasingly amongst different populations around the world, and the labor community is no exception to this rule. A study in the Asalouyeh industrial region (Located in the southwest of Iran) showed that drug use among camp workers is between 15% and 25%, and the most commonly used opium. Reports indicate that opioids reduce the secretion of LH and FSH gonadotropins by inhibiting the release of gonadotropin releasing hormone secreted from the hypothalamus, while gonadotropins are crucial for the survival of testicular cells, and their reduction to planned cell death. The results of previous studies confirmed that exposure to noise and opium consumption alone had a downward effect on the level of sex hormones on human and animal samples. The aim of this study was to investigate the effects of exposure to noise and opium consumption on sex hormones in male animal models (rat). Methods: In this Experimental and cross-sectional study which was completed in 2018, 36 healthy adult male Wistar rats (purchased from the Tehran Pasteur Institute) were randomly divided into six groups (after initial screening from the point of view weight, age, etc.); control, exposure to noise (100 dB and 700-5700 Hz frequency range for 8h/day), consumption of opium solution(50 mg per case), consumption of opium solution(100 mg per case), exposure to noise (100 dB and 700-5700 Hz frequency range for 8h/day), consumption of opium solution(50 mg per case) and exposure to noise(100 dB and 700-5700 Hz frequency range for 8h/day) and consumption of opium solution(100 mg per case). The frequency range of 700 to 5700 Hz was chosen from a combination of 1000, 2000, and 4000 Hz central frequencies in octave band spectrum (based on rat and human hearing sensivity in this range). Noise level (100 dB) was produced by signal software and implemented by Cool -Edit software. After boosting with an amplifier, with installation of four speakers on top of the chamber, the noise was broadcast in the reverberant chamber. The dimensions of the reverberant chamber (Plexiglas) were selected based on the Bolts chart, the required space per rat and the animal welfare (49×59×30 cm with 5 mm thickness). The noise level was monitored during exposure by calibrated sound level meter (model cel-450) hourly. The air inside the chamber was changed 12 times every hour. Opium was prepared by getting the necessary Legal licenses from the police and the Food and Drug Administration and then opium solution (dissolved in hot distilled water) was fed to animals at different doses (50 and 100 mg per case) through gavage tube between 6:30 to 7:00. In order to ensure that the rats were addicted (groups 3, 4, 5, and 6), at the end of the first week, with naloxone injection (2 mg per kg), the hangover symptoms of the animal were evaluated and the addiction was confirmed. The ambient temperature of the animal house was adjusted throughout the test period in the range of 20-24 ċ. After 50 days (cycle of spermatogenesis in rats), following anesthesia (Xylazine - ketamine), blood samples were collected (5 ml of the left ventricle). Using centrifuge, the serum should be discarded at 3000 rpm for 15 minutes. Level of sex hormones (testosterone, follicular stimulatory and luteinizing hormones) was determined by specific rat kits (producted by Zelbio Company) and ELISA technique. The ethics of working with animals, according to the Helsinki Statement and the Ethics Committee of Tarbiat Modares University, were observed at all stages of the study. Data analysis was performed with SPSS software (version 22 by using ANOVA test (Tukey Post hoc test). Results: This study is a first study in the world that examine the effect of exposure to noise and opium consumption on sex hormone levels in an animal model. In this study, noise could significantly suppress the levels of testosterone and luteinizing hormones, but did not affect the level of follicular stimulatory hormones. The results of this study (about the noise agent) are consistent with studies by Swami et al., Paramanik et al. And Rafuli et al. Both doses of opium solution (50 and 100 mg per case) can significantly reduce the level of sex hormones (testosterone, follicular stimulatory and luteinizing hormones) However, no significant difference was found in the two doses in any of the examined hormones. In 2012, the study of Yasin Kahimin showed that levels of testosterone decreased significantly in opioid recipient groups, which were consistent with the results of the present study in relation to lowering the secretion of testosterone and LH. A study by Salman et al in 2010 showed that levels of testosterone, LH and FSH in opiate addicted men decreased significantly compared to control group. Sepehri et al. Study showed that levels of LH, FSH and testosterone levels in addicted people were significantly lower than those in the control group. Combining the two factors of noise and opium (with opium solution doses of 50 and 100 mg per rat) could have significant boosting effects in suppressing levels of testosterone and luteinizing hormones while this enhancing effect was assessed for an increase in follicular stimulatory hormones(Comparison of groups 5 and 6 compared to control group). Increasing the opium solution dose from 50 to 100 mg per rat did not make a significant difference in the level of sex hormones (comparison of groups 3 and 4 as well as groups 5 and 6). In this study, the noise and opium solution did not significantly change the rat weight in variouse groups compared to control group. In the first week of the study, gastrointestinal disorders (such as diarrhea) were observed in the exposed group, but over time, this disorder was eliminated. Conclusion: The use of opium for medicinal or recreational purposes has a high historical background in many parts of the world. Due to the effect of reducing the effect of two factors of noise and opium addiction on the level of testosterone and luteinizing hormones, It is suggested that the reduction of the hormones mentioned in the periodic examinations of workers should be considered and emphasized by professional and medical professionals and considered as a prognosis for infertility. More studies are needed to determine the effect mechanism of noise and opium consumption on pituitary-gonad axis. In this study, only opium was used as one of the most commonly used drugs in the community Therefore, it is suggested that future studies on narcotics such as heroin, cannabis, etc. should be put on the agenda of researchers. In order to cope with the destructive effects of exposure to noise and other harmful physical hazards in the working environments, various methods of engineering, management, or use of inexpensive and available antioxidants, such as cinnamon, can be used. Based on the results, it can be concluded that chronic consumption of opium can significantly decrease the function of gonad-pituitary secretion, and this can lead to suppression of libido and infertility. It is suggested that the effects of opium in different doses should be considered in future generations.
