Effect of passive smoking on the behavior and emotion of rats with acute sleep deprivation

Qiujun YU; Jing ZHAO; Fange LIU; Jing LI; Weijun ZHU; Xiaokang LI

ABSTRACT

BACKGROUND:

Sleep deprivation, resulting in a series of physiological and psychological reactions, is a common phenomenon in our modem society. Recently, many physical and medical therapies are on their way to eliminate the negative influence the sleep deprivation exerted on our human beings, and a large number of cigarette smokers believe that cigarette smoke can obviously improve their abnormal behavioral performance and negative emotional fluctuation caused by sleep deprivation in short terms.However, there are few researches but many disputes when it comes to effect of passive smoking on the behavior and emotion of rats on the occasion of acute sleep deprivation.

OBJECTIVE:

To investigate the effect of passive smoking (PS) on the behavior and emotion of rats with acute sleep deprivation (SD).

DESIGN:

Completed randomized and controlled study.

SETTING:

Basic Medicine Experiment Center, School of Basic Medicine;Department of Radiation Medicine, School of Preventive Medicine, Fourth Military Medical University of Chinese PLA.MATERIALS The experiment was carried out at Experiment Center of Basic Medicine, Fourth Military Medical University of Chinese PLA from April to June 2004. Totally 49 healthy adult male Sprague-Dawley rats,being 3 months old, weighting (180±15) g, were randomly divided into 5groups sleep deprivation + 24-hour passive smoking group (n=8), 24-hour sleep deprivation group (n=8), sleep deprivation + 54-hour passive smoking group (n=8), 54-hour sleep deprivation group (n=8), and blank control group (n=7).

METHODS:

① Rats in sleep deprivation + 24-hour passive smoking group, 24-hour sleep deprivation group, sleep deprivation + 54-hour passive smoking group and 54-hour sleep deprivation group were performed with sleep deprivation with flower pot method for 24 and 54 hours, and rats in sleep deprivation + 24-hour passive smoking group and sleep deprivation + 54-hour passive smoking group were treated with passive smoking at the same time at a frequency of 12 times/day, 120 minute/time, 3cigarettes were lighted at the same time and kept into ashes. ② Broad field test was conducted to determine the behavioral and emotional changes of the rats. We trailed their activities by video recorder for 5 minutes each time. Then we presented the image information to computer process and finally got the total distance and the average distance from the center of the broad field for each rat during the 5-minite test. Meanwhile, we also observed the emotional variety and excitability of the rats. The nearer the average distance from center was, the more the emotional behavior and the greater excitability were; and the longer the total distance was, the greater the excitability was. ③ All the data were expressed with Mean ± SD, the method of non-parametric rank sum test was adopte d for comparing among groups, P ＜ 0.05 was regarded as statistical significance.MAIN OUTCOME

MEASURES:

Comparisons between DC and TD of rats in each group, and changes of behavior and emotion of rats in each group.

RESULTS:

Data of all the 49 rats was entered the final data analysis without any loss. ① Observation of emotional stage Compared with sleep deprivation + 54-hour passive smoking group, rats in sleep deprivation+24-hour passive smoking group appeared more quiet and indifferent, and presented lower excitability, less sensitivity to outside stimulus and less aggressive behaviors towards other rats, and the same as 24-hour sleep deprivation group, compared with 54-hour sleep deprivation group. ② Results from the open field test DC of 24-hour sleep deprivation group was significantly smaller than that of blank control group and sleep deprivation + 24-hour passive smoking group [(53.93±1.83, 58.21±4.45, 58.11±1.62) cm, (P＜ 0.01-0.05)]. DC of 54-hour sleep deprivation group was significantly bigger than that of 24-hour sleep deprivation group [(61.53±3.02, 58.11±1.62) cm, (P＜ 0.01)]; TD of 24-hour sleep deprivation group was significantly bigger than that of sleep deprivation + 24-hour passive smoking group [(3310.45±1 445.97, 1 818.20±733.25, 2 338.15±694.70) cm, (P ＜ 0.01-0.05)], and that of 54-hour sleep deprivation group was bigger than that of sleep deprivation + 54-hour passive smoking group andsmaller than that of 24-hour sleep deprivation group [(2 410.70t548.64, 1 473.50±945.89, 3 310.45±1 445.97) cm, (P＜0.05)].

CONCLUSION:

With the prolongation of sleep deprivation time, behavior and emotional reaction of rats are shown from exciting to inhibiting, however, passive smoking can inhibit behavior and emotional state of rats during the whole sleep deprivation.