Department of Physiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Physiol Res. 2019 Dec 20;68(Suppl 3):S339-S346. doi: 10.33549/physiolres.934357.
Drug addiction and its consequences on social life and behavior is currently a worldwide problem. Methamphetamine (MA) is one of the most abused psychostimulants in the Czech Republic. MA elevates mood, increases concentration, reduces appetite, and promotes weight loss. However, high doses and long-term abuse can induce psychosis, hallucinations, paranoia, violent behavior, and can lead to cardiovascular problems. Regarding its high prevalence and negative impact on health and social life, MA needs to be fully investigated. Previous studies have demonstrated the impairing effect of MA drug abuse on female behavior. However, MA's influence on male sexual behavior is not entirely clear. The aim of this study was to examine the effect of MA exposure on sexual behavior and spontaneous locomotor activity of adult male rats. MA was administrated subcutaneously at a dose of 5 mg/kg daily for a period of 30 days. The control group was exposed to saline (SA) at the same time and same volume. At the end of the application period, exposed male rats were paired with non-treated female rats, and their behavior was recorded for 2 h. Sexual mating behavior was described in terms of mounting frequency, intromission frequency, ejaculation frequency, sniffing time, intromission latency and the post-ejaculatory interval. Spontaneous locomotor activity in postnatally exposed male rats was studied using the Laboras apparatus. Acute doses of MA (1 mg/kg) or SA were administrated to probe the sensitizing effect of previous chronic MA exposure. Afterward, the animal was placed in an unknown environment and monitored for 1 h. Behavior was automatically evaluated using Laboras software by analyzing the following parameters: duration of locomotion (s), duration of immobility (s), rearing (vertical exploratory behavior), time spent grooming (s), average speed (mm/s), and distance traveled (m). Our results indicate that MA administration has a negligible effect on the sexual behavior of adult male rats. However, more experiments have to be performed to examine the influence of MA exposure on spermatogenesis and the behavior of offspring. Data from the Laboras test showed that MA exposure has a significant effect on locomotor activity in both acute as well as subchronic MA application. In conclusion, our results show that administration of MA in adult male rats does not affect sexual performance and motivation but does increase locomotor and exploratory activity in an unknown environment.
药物成瘾及其对社会生活和行为的影响是目前全球范围内的一个问题。甲基苯丙胺（MA）是捷克共和国最滥用的一种精神兴奋剂。MA 能提高情绪、增强注意力、减少食欲并促进体重减轻。然而，高剂量和长期滥用会导致精神病、幻觉、偏执、暴力行为，并可能导致心血管问题。鉴于其高患病率以及对健康和社会生活的负面影响，需要对 MA 进行全面研究。先前的研究已经证明了 MA 药物滥用对女性行为的损害作用。然而，MA 对男性性行为的影响并不完全清楚。本研究的目的是检查 MA 暴露对成年雄性大鼠性行为和自发运动活动的影响。MA 以 5mg/kg 的剂量每天皮下注射，持续 30 天。对照组同时和相同体积暴露于生理盐水（SA）。在应用期结束时，暴露的雄性大鼠与未经处理的雌性大鼠配对，并记录它们的行为 2 小时。性行为描述为交配频率、插入频率、射精频率、嗅探时间、插入潜伏期和射精后间隔。通过 Laboras 仪器研究了暴露于 MA 的雄性大鼠的自发运动活动。给予 MA（1mg/kg）或 SA 的急性剂量以探测先前慢性 MA 暴露的敏化作用。之后，将动物置于未知环境中并监测 1 小时。使用 Laboras 软件自动评估行为，通过分析以下参数来评估：运动持续时间（s）、静止持续时间（s）、竖立探索行为（直立探索行为）、梳理时间（s）、平均速度（mm/s）和行驶距离（m）。我们的结果表明，MA 给药对成年雄性大鼠的性行为几乎没有影响。但是，需要进行更多的实验来检查 MA 暴露对精子发生和后代行为的影响。Laboras 测试的数据表明，MA 暴露对急性和亚慢性 MA 应用中的运动活动都有显著影响。总之，我们的结果表明，在成年雄性大鼠中给予 MA 不会影响性行为表现和动机，但会增加在未知环境中的运动和探索活动。
