Anxiolytic-like activity of Aloysia virgatavar. platyphylla leaves extract in mice / Actividad ansiolítica del extracto de hojas de Aloysia virgatavar. platyphylla en ratones

Background: Medicinal plants are part of traditional medicine and should be considered a therapeutic alternative for mental diseases. Several plants belonging to the Verbenaceae family have proved useful in treating general anxiety disorders, the most prevalent psychiatric disorders. Objective: This research aimed to verify the extract's safety, the effect on general behavior, and the effect on sleeping time, as well as to evaluate the anxiolytic-like effect of the methanol extract of Aloysia virgata var. platyphylla (Avp), in mice. Methodology: The toxicity test was done according to the OECD guide (mice groups n=5), and general behavior was observed during the assay. Sleeping time was assessed using the pentobarbital-induced hypnosis method (n=8). Male Swiss albino mice (n=6) were treated with 50 to 400 mg/kg of Avp extract and diazepam as a control. The anxiolytic-like effect was tested through the hole board and elevated plus-maze test. Results: The Avp extract has no side effects in tested doses, and no central nervous system depressant activity was noted. A. virgatavar. platyphyllaincreased exploration (number and time) in the hole board. In the elevated plus-maze, increased number and time into open arms were evidenced compared to the control group. Conclusion: With all these results, we concluded that the Avp extract is safe and has a potential anxiolytic-like activity in the animal model used

Antecedentes: Las plantas medicinales forman parte de la medicina tradicional y deben ser consideradas una alternativa terapéutica para las enfermedades mentales. Varias plantas pertenecientes a la familia Verbenaceae han demostrado su utilidad en el tratamiento de los trastornos de ansiedad, uno de los trastornos psiquiátricos más prevalentes. Objetivo: Esta investigación tuvo como objetivo verificar la seguridad del extracto, el efecto sobre el comportamiento general y el efecto sobre el tiempo de sueño, así como evaluar el efecto tipo ansiolítico del extracto metanólico de Aloysia virgata var. platyphylla(Avp), en ratones. Metodología: La prueba de toxicidad se realizó de acuerdo con la guía de la OCDE (grupos de ratones n=5), y se observó el comportamiento general durante el ensayo. El tiempo de sueño se evaluó mediante el método de hipnosis inducida por pentobarbital (n=8). Se trataron ratones albinos suizos macho (n=6) con 50 a 400 mg/kg de extracto de Avp y diazepam como control. El efecto ansiolítico se probó a través de la placa perforada y prueba del laberinto en cruz elevado. Resultados: El extracto de Avp no tiene efectos secundarios en las dosis probadas y no se observó actividad depresora del sistema nervioso central. A. virgata var. platyphylla aumentó la exploración (número y tiempo) en el tablero de agujeros. En el laberinto en cruz elevado, se evidenció un mayor número y tiempo en los brazos abiertos en comparación con el grupo de control. Conclusión: Con todos estos resultados, concluimos que el extracto de Avp es seguro y tiene una potencial actividad ansiolítica en el modelo animal utilizado

Assessment of General effects and gastrointestinal prokinetic activity of Baccharis crispa in mice

Baccharis crispa is commonly known to be used in the treatment of several digestive disorders and the primarypurpose of this study was to detect its acute toxicity. Its influence on general behavior, sleeping time and intestinaltransit activity in mice were followed as a mean of initial validation for popular use. The gastrointestinal effectwas determined by testing the influence of B. crispa (Bc) on both intestinal motility (in vivo) and spontaneouscontractile response of isolated ileum (in vitro). Oral administration of Bc showed low toxicity and induced asignificant shortening of sleeping time in mice. After in vitro evaluation on isolated ileum, doses of 5.10−4; 10−4and 5.10−3 mg/mL of Bc potentiated the contractile response to acetylcholine. The intestinal propulsive activityincreased with oral doses of 1, 5 and 50 mg/kg of Bc. After in vitro and in vivo gastrointestinal evaluations ofBc extract, it was clear that an efficient prokinetic activity and a significant increase in spontaneous contractioninduced by acetylcholine in isolated mouse ileum occurred. These results partially support and justify thetraditional use of B. crispa to treat gastrointestinal disorders.

Association between age of first spermatorrhea and physical activity or sleeping time in boys / 上海交通大学学报（医学版）

Objective · To understand boys' pubertal timing in school in two urban districts of Chongqing and explore the relationship between pubertal timing and physical activity or sleeping time. Methods · Using a stratified random cluster sampling, 3403 boy students (10-18 year-old) were selected and completed the physical examination and questionnaire survey. 1282 participants experiencing first spermatorrhea were chosen as research objects. According to age of first spermatorrhea, the objects were divided into on-time group (964 cases) and later group (318 cases). Results · The composition of weekly high (χ2=11.488, P=0.009), medium (χ2=7.829, P=0.050) physical activity and daily sleeping time (χ2=17.803, P=0.000) in two groups were significantly different. Controlling covariates (age, height and weight), compared with boys in on-time group, later group boys were less likely to engage in 5-7 days (OR=0.596, 95% CI: 0.367-0.967) and 3-4 days (OR=0.590, 95% CI: 0.370-0.941) high physical activity every week, and 9-11 h (OR=0.207, 95% CI: 0.088-0.489) sleep every day. Conclusion · The age of first spermatorrhea in boys might be associated with the intensity of weekly physical activity and daily sleeping time.

Research on the relationship of recurrence of cerebral infarction with total sleeping time / 医学研究生学报

Objective Cerebral infarction is a main disease threatening human health and the recurrence of cerebral infarction is more inclined to cause disability and death.The article aimed to explore the influence of total sleeping time on the recurrence of cerebral infarction.Methods According to the criteria, 70 cases of cerebral infarction patients who hospitalized in our hospital from March 2016 to November 2016 were selected to undergo polysomnography (PSG) and were divided into two groups according to medical history: original group and recurrence group.Another 20 simultaneous outpatients who had no significant diseases to undergo PSG were chosen as the control group.Data were collected on all the individual''s total sleeping time (TST), gender and age.Hypothesis testing and logistic related analysis were applied in data analysis.Results The TST of recurrence group was shorter than those of the original group and the control group (P<0.05), among which the TST of the original group is shorter than that of the control group (P<0.05), both representing significant difference.Multiple regression analysis showed that TST was an independent risk factor for the recurrence of cerebral infarction and that the risk of recurrence of cerebral infarction increased with the lack of TST.Conclusion The shortening of TST may increase the risk of the recurrence of cerebral infarction.

Neuropharmacological effects of the ethanolic extract of Sida acuta

ABSTRACT Sida acuta Burm. f., Malvaceae, is regarded as astringent, tonic and useful in treating urinary diseases and blood disorders, bile, liver and as treatment for nervous diseases. Different methods were developed: sodium pentobarbital-induced sleeping time, anxiolytic activity, test for muscle-effects, pentylenetetrazole (PTZ)-induced seizures, effect on normal body temperature. All experiments were performed in an isolated room with 12/12 h light/dark cycles at 22 ± 1 ºC. The effects described in this work for Sida acuta are according to what is known in traditional medicine, where is used as sedative agent. At the higher doses used in this work (500 and 1000 mg/kg), the Sida acuta extract reduced the latency time (T1) and increased the sleeping time (T2) induced by pentobarbital, indicating a sedative and hypnotic effect of the plant's extract. The extract of Sida acuta shows an increase in open arm exploration (anxiolytic activity). Results obtained in the rota-rod test showed that only the elevated dose (750 mg/kg) of Sida acuta extract, acutely administered, promotes significant changes, at 60 and 120 min post-administration, in the time of permanence in the rod. The ethanolic extract from the leaves and stems of Sida acuta, causes effects on the central nervous system in experimental animals.

Effect of sleeping time on psychological state and quality of life in patients with type 2 diabetes / 军事医学

Objective To observe the sleeping time and analyze its impact on the psychological state and quality of life of patients with type 2 diabetes .Methods Convenience sampling was used to recruit 365 patients with type 2 diabetes in Jiangsu Province Hospital on Integration of Chinese and Western Medicine Affiliated to Nanjing University of Chinese Medicine between April 2014 and April 2015 .All the patients were divided into two groups according to the six-hour cut-off point of sleeping time .They were investigated by means of World Health Organization Quality of Life-BREF ( WHOQOL-BREF), Diabetes Distress Scale ( DDS) and General Self-Efficacy Scale ( GSES).Data were analyzed by t-test, chi-square test, Mann-Whitney U test and multivariate regression analysis .Results The average sleeping time was 7.03 h, and the sleeping time of 109 patients was less than 6 h.Patients with less sleeping time had lower quality of life and self-efficacy scores as well as higher diabetes distress scores than those with sleeping time more than 6 h.The differences were statistically significant (P<0.05).Regression analysis showed that sleeping time was the factor of quality of life (β=0.117, P=0.047), self-efficacy (β=0.136, P=0.024) and diabetes distress(β=-0.118, P=0.046).Conclusion Sleeping time affects the psychological state and quality of life of patients with type 2 diabetes.The medical should pay more attention to the quality of sleep of such patients .

Interaction of two memory enhancing herbal drugs Memory Plus and Mentat with diazepam and phenytoin sodium in mice.

Background: The non-medical self-administration of memory enhancing drugs is a common practice. Present study was designed to evaluate interactions of two such herbal drugs Memory Plus (MP) and Mentat, with other central nervous system (CNS) active drugs. Methods: Two activities - pentobarbitone sleeping time (PST) and maximal electroshock seizures (MES) were performed using adult albino mice weighing 25-30 g to observe the interactions of the herbal drugs with diazepam and phenytoin sodium, respectively. For each activity, animals were divided into seven groups of six mice each. Group I was a control group receiving 0.2 ml of 1% Tween 80 i.p/0.2 ml saline p.o, Group II, III and IV acute treatment groups; received single dose of herbal (2 mg/kg i.p MP or 200 mg/kg p.o Mentat) CNS-active drugs alone in subeffective doses group II - diazepam 5 mg/kg i.p, Group III PS 15 mg/kg i.p and Group IV - MP/Mentat+diazepam or PS, respectively. Groups V, VI, and VII were subchronic treatment groups, received drugs once daily for 8 days same as acute treatment groups. Sleeping time was measured as the interval between the loss and recovery of righting refl ex and anticonvulsant activity by giving supra maximal shock via ear electrodes using a techno electro convulsiometer. Results: Both MP and Mentat showed potentiation of effect of diazepam and PS in subchronic treatment groups by signifi cantly prolonging PST (p<0.05) and by showing signifi cant percentage protection in MES method (p<0.05) compared to control group. Conclusion: Subchronic administration of MP and Mentat shows significant interaction with diazepam and PS. Further human studies are warranted to confi rm these fi ndings.

Effects of Acupuncture on Sleeping Time and Striatum 5-HT and DA Content in Rats with ;Stress Induced Gastric Mucosal Injury / 中国中医药信息杂志

Objective To observe the effects of acupuncture on the sleeping quality of male Wistar rats with stress induced gastric mucosal injury from the viewpoint of the brain-intestine axis. Methods Male Wistar rats were randomized into normal control, model, ST36-CV12, BL62-KI6, and combined groups, with 8 rats in each group. The model was established by using intragastric perfusion of ethanol in the rats. Acupoints of Zusanli (ST36) and Zhongwan (CV12) on both sides were used for the ST36-CV12 group. Acupoints of Shenmai (BL62) and Zhaohai (KI6) on both sides were used for the BL62-KI6 group. All four acupoints were used for the combined group. 0.22 mm × 13 mm stainless steel filiform needles were inserted 5-10 mm deep, and were left untouched for 20 minutes before withdrawal. The acupoints were stimulated each day for five days and the paw withdraw thermal latency (PWTL) was detected after the last stimulation. 2%pentobarbital sodium was then injected (40 mg/kg), and sleeping time of rats was detected. Gastric mucosa was observed through naked eyes. Gastric mucosal ulcer Index was determined by using the Guth method. 5-HT and DA contents were detected by using HPLC-ECD method. Results Compared with the normal control group, PWTL and sleeping time decreased (P<0.01), and UI, 5-HT, and DA content increased in model group (P<0.05, P<0.01). Compared with the model group, PTWL and sleeping time increased (P<0.05, P<0.01), and UI decreased in all treatment groups (P<0.01). 5-HT content in ST36-CV12 and combined groups decreased significantly, and DA content in ST36-CV12 group dropped (P<0.01). Compared with other treatment groups, PWTL and sleeping time increased significantly (P<0.01), and UI decreased obviously in combined group (P<0.01). Conclusion Stimulating acupoints of Zusanli, Zhongwan, Shenmai, and Zhaohai (KI6) may promote the recovery of gastric mucosal injury while at the same time increase sleeping time, with four acupoints used in combination having the best efficacy. The mechanism may be related to adjusting contents of 5-HT and DA in corpus striatum.

Isolation of compound and CNS depressant activities of Mikania scandens Willd with special emphasis to brain biogenic amines in mice.

Mikania scandens, a twining herb that grows as a weed in India and Bangladesh is used as vegetables and is a good source of vitamin A, C, B complex, mikanin, sesquiterpenes, betasitosterin, stigmasterol and friedelin. The present communication reports CNS depressant activities with special emphasis to brain biogenic amines in mice. Ethanol extract of leaves of M. scandens (EEMS) was prepared by Soxhalation and analyzed chemically. EEMS potentiated sleeping time induced by pentobarbitone, diazepam and meprobamate and showed significant reduction in the number of writhes and stretches. EEMS caused significant protection against pentylene tetrazole-induced convulsion and increased catecholamines and brain amino acids level significantly. Results showed that EEMS produced good CNS depressant effects in mice.

Effect of eszopiclone on pentobarbital sodium-induced sleeping time in acute hypobaric hypoxia mice / 中华行为医学与脑科学杂志

Objective To assess the effects of eszopiclone (ESZ) on the pentobarbital sodium-induced sleeping time and spontaneous activity in mice exposed to acute hypobaric hypoxia.Methods 120 mice were randomly divided into 6 groups by using two factors 2×3 levels factorial design,in which two factors were interventions (ESZ and 0.9％ sodium chloride,2 levels) and altitudes (800 m,3500 m and 6000 m,3 levels).The pentobarbital sodium-induced sleeping test and the open field test were engaged to assess the effects of ESZ on sleeping time and spontaneous activity.Results (1) The drug and altitude had no interaction in the results of both the pentobarbital sodium-induced sleeping test and the open field test(P＞0.05).(2)The time of pentobarbital sodium-induced sleeping of mice in the groups of ESZ at each altitudes were (37.77± 18.22) min,(37.02± 13.67) min,(95.67±47.68)min and in the groups of NS were(17.78± 14.10) min,(15.09± 12.46) min,(39.54±28.24) min respectively,and the sleep time in ESZ groups were significantly longer than those in the groups of NS (P＜0.05).The time of pentobarbital sodium-induced sleeping were longer in group of 6000 m than those in the other two groups,both the ESZ and NS groups (P＜0.05).(3)No significant difference was found in the open field test between the ESZ and NS groups in the same altitude(P＞0.05) ; while the mice at the altitude of 6000 m in groups of ESZ and NS decreased compared with the groups at the altitude of 800 m after the relevant drugs intra-perineally for 6 h (P＜0.05).Conclusion ESZ may prolong pentobarbital sodium-induced sleeping time especially at the altitude of 6000 m and with no influence on the spontaneous activity in mice exposed to acute hypobaric hypoxia.High altitude at 6000 m may prolong the sleep time induced by pentobarbital sodium and reduce the spontaneous activities.

Effect of intermittent hypobaric hypoxia on efficacy & clearance of drugs.

Background & objectives: People travelling to high altitude for occupational, recreational or religious purposes are mostly healthy and fit but sometimes they use drugs for common ailments like influenza, acute mountain sickness or chronic disease like diabetes. Limitation of oxygen at high altitude may compromise metabolism of drugs. Hence, we undertook this study to assess the effect of hypobaric hypoxia on some commonly used drugs in rats and rabbits. Methods: Effect of intermittent hypobaric hypoxia on phenotypic expression of anesthetic drugs pentabarbitone, thiopentone and zoxazolamine (sleeping time) was assessed in rats exposed to 282.4 mm Hg equivalent to 25000 feet in a decompression chamber. Plasma clearance of some commonly used drugs was investigated in rabbits exposed to 429 mm Hg equivalent to 15000 feet. Pharmacokinetic parameters were computed by plotting drug concentration versus time curve on semi log scale. Results: A significant delay in regaining rightening reflex was observed in rats exposed to intermittent hypobaric hypoxia in response to zoxazolamine, pentobarbitone and thiopentone sodium. Pharmacokinetics of acetyl salicylic acid, gentamicin, phenobarbitone and acetazolamide showed increase in plasma half life (t1/2), decrease in elimination rate constant (kel) and hence prolonged residence of these drugs in hypoxic animals. Interpretation & conclusions: This experimental study showed that hypoxia altered therapeutic effectiveness and clearance of several drugs, in rats and rabbits exposed to intermittent hypobaric hypoxia. s0 uch studies need to be done in human volunteers to see the effect of hypoxia on pharmacokinetics of some common drugs.

Comparisons of Body Image Perception, Health Related Lifestyle and Dietary Behavior Based on the Self-Rated Health of University Students in Seoul / 대한지역사회영양학회지

This study was conducted to examine the differences in perceived body weight and image and various lifestyles based on the self-rated health of university students when gender was adjusted. Five hundred fifty-five participants were asked their perceived health condition, and 58, 289, 160 and 48 students answered themselves as "very healthy", "healthy", "normal", and "unhealthy", respectively. As compared to the other 3 groups, "unhealthy" group showed higher proportions in dissatisfaction of body weight and negative perception of body image (P < 0.01). As health related lifestyles, "very healthy" group reported longer sleeping time than "unhealthy" group (P < 0.05), and had a higher proportion of people with regular exercise. Among the dietary behaviors, the frequencies of followings significantly different among the groups: "Regularity of meal time" (P < 0.01), "Eat protein foods more than twice a day" (P < 0.001), "Eat vegetables" (P < 0.01), "Eat fruit and fruit juice" (P < 0.01), "Eat vegetable oil added foods" (P < 0.01), "Eat seaweed" (P < 0.01), "Eat breakfast" (P < 0.01), "Modulation in animal fat and high in cholesterol intake" (P < 0.01). Particularly, higher proportion of subjects answered "very healthy" had higher frequencies (6-7 times/week) of these dietary behaviors. Overall results suggest that healthy lifestyle including adequate sleeping time, regular exercise, and good dietary behaviors might be potential factors affecting positive perception of health. In addition, positive perception of body weight and image were related with positive perception of health.

Hypnotic effect of ecdysterone isolated from Pfaffia glomerata (Spreng.) Pedersen / Efeito hipinótico de ecdisterona isolada de Pfaffia glomerata (Spreng.) Pedersen

Neste trabalho foi avaliado, em roedores, o efeito depressor das frações clorofórmio (CHCl3), acetato de etila (EtOAc) e n-butanol, obtidas das partes subterrâneas de Pfaffia glomerata, empregando-se o teste de tempo de sono barbitúrico como referência. Somente a fração lipofílica (CHCl3:EtOAc, 1:1, m/m) (i.p. 500 mg/kg; v.o. 1000 mg/kg) potenciou o tempo de sono induzido por pentobarbital. A ecdisterona foi isolada e identificada como constituinte majoritário (1,4 por cento m/m) desta fração, através de cromatografia líquida de alta eficiência e métodos espectroscópicos, respectivamente. Este composto potenciou o tempo de sono barbitúrico (100 mg/kg, i.p.; 400 mg/kg, v.o), sem causar hipotermia. Nestas mesmas doses, a ecdisterona não alterou a performance dos animais no rota-rod, esquiva inibitória e labirinto em cruz-elevado, além de não alterar o padrão de convulsões induzidas por pentilenotetrazol. Este perfil indica que esta substância, nestas doses, não apresenta perfil ansiolítico ou neurotóxico. Estes resultados indicam que a ecdisterona é o componente responsável pela ação hipnótica apresentada pela fração lipofílica obtida das partes subterrâneas de P. glomerata.

In this study the depressant effect of fractions from P. glomerata was initially evaluated using the mice barbiturate sleeping time test as reference. The fractions tested were the CHCl3, the EtOAc, the n-BuOH and the aqueous fraction obtained from P. glomerata subterraneous parts. Only the pretreatment with the lipophilic fraction (CHCl3: EtOAc, 1:1, w/w) increased the barbiturate sleeping time (i.p 500 mg/kg; v.o. 1000 mg/kg). Ecdysterone, the main substance isolated from this lipophilic fraction, was identified by spectroscopic methods and its content in the ethanol extract was determined as 1.4 percent (w/w) by HPLC. In order to investigate the hypothesis of ecdysterone displaying a depressant effect on nervous central system, an evaluation toward the hypnotic-sedative and anxiolytic effects of this drug was carried out. Ecdysterone 100 mg/kg, i.p, increased the barbiturate sleeping time without provoking hypothermia; when administered by oral route its minimal effective dose was 400 mg/kg. On the other hand, ecdysterone (100 mg/kg, i.p; 400 mg/kg, p.o) did not impair motor coordination and was ineffective on pentylenetetrazole-induced convulsion, elevated plus-maze and step-down inhibitory avoidance tests, indicating that at these doses the drug does not present an anxiolytic profile and does not cause manifest neurotoxic effects as well. In conclusion, the lipophilic fraction from P. glomerata presents a hypnotic effect being ecdysterone one of the compounds responsible for this CNS activity.

Analysis on Sleeping Time among Chinese Population / 中国慢性病预防与控制

Objective To describe the status of sleeping time among Chinese population.Method The data of 2002 China National Nutrition and Health Survey was used for the analysis.197 954 subjects aged 6 years and above were involved.Results The average daily sleeping time of the domestic Chinese was 8.3 hrs.In groups of 6～12 yrs,13～17 yrs,18～44 yrs,45～59 yrs,60 yrs and above,the daily sleeping time were 9.1 hrs,8.5 hrs,8.2 hrs,7.9 hrs and 7.8 hrs,and the rate of insufficient sleeping was 69.0%,58.5%,4.1%,9.2% and 17.1%,respectively.The rate of excessive sleeping in groups of 18～44 yrs,45～59 yrs and 60 yrs and above were 27.1%,20.2%,24.3%,respectively.Conclusion The status of insufficient and excessive sleeping existed in Chinese at the same time,and further research should be developed on the association between sleeping time and health.

Relation of Lifestyle Variables to Total Mortality in a Cohort of Old Residents Aged 60-64 in a Rural Community

BACKGROUND: This prospective cohort study was carried out to investigate the relation of lifestyle variables to total mortality in residents aged 60-64 of a rural community in Korea. METHODS: A total of 1,042 residents was interviewed by face-to-face survey for baseline data collection in 1996 and 955 residents were successfully followed up until April 2002, among which 91 died. RESULTS: In univariate logistic regression, consumption of cigarette per day, duration of smoking, status of smoking, frequency of drinking per month, status of drinking, average duration of TV watching per day and average duration of sleeping were statistically significant, predicting total mortality. None of the variables reflecting leisure-time physical activities were statistically significant. Adjusting for sex, age, education, current as well as past chronic diseases history, and limitation of daily living with multiple logistic regression, those smoking more than 40 years and current smokers showed reduced, but statistically significant RRs, 1.89 (95% CI 1.05-3.41) and 1.82 (95% CI 1.01-3.25), respectively. Sleeping more than 10 hours a day showed RR, 2.41 (95% CI 1.11-5.22). CONCLUSION: These results suggested that some lifestyle variables, smoking and sleeping were predictive of total mortality while drinking, TV watching and leisure-time physical activities were not.

Relationship between stress amounts and health habits about nurses in one hospital

BACKGROUND: Stress is found to have influence on physical and mental disorders, and also to healthy life habits related to physical health mental stress. Job holders are groups that have suffered from chronic stressful condition. Consider medical people of job holders to received exess stress. So, we tested this investigation to know the relationship between health habits and stress amounts about nurse. METHODS: This study was performed on nurses who worked on one hosptal in Pusan Metropolitan city for one months(from April, 1, to April, 30, 2000). We used 128 results. Health habits were investigated about 5 articles out of "Breslow's 7 health habits" and stress amounts were measured by Korean translated BEPSI(Brief Encounter Psychosocial Instrument) and Bae Jong Myun's 30 items SRRQ(Social Readjustment Rating Questionnaire). RESULTS: There were differences in amounts of stress of subjects according to marital state(P<0.05), job department(P<0.05), BMI(Body Mass Index)(P<0.05), sleeping time(P<0.05). CONCLUSION: This investigation has showed that having excess stress in nurses. Body Mass Index, sleeping time appeared to be health habits related to amounts of stress.

THE EFFECTS OF CIMETIDINE & RANITIDINE ON PENTO-BARBITAL SLEEPING TIMES IN RATS & MICE / 中国药理学通报

The pentobarbital sleeping times ( PST ) in rats and mice pretreated with ranitidine acutely or chronically do not differ significantly from the control groups. But the PST pretreated with cimetidine acutely and chronically both do prolong significantly in rats and mice. The blood pentobarbital concentration in the male rats pretreated with cimetidine chronically is significantly higher than the ranitidine and control groups. Close relationship between the PST and the blood pentobarbital concentration has been observed.