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Background: Not all second-generation antihistamines were devoid of the central nervous system (CNS) effects such as cognitive and psychomotor impairment. Although these drugs penetrate blood–brain barrier (BBB) to lesser extent, many of them have been found to produce dose-related impairment of CNS functions with interdrug differences present among them. Aim and Objective: This study is aimed to analyze and compare the effects of different antihistamines (first and second generation) on the CNS using Swiss albino mice. Materials and Methods: Twenty-four Swiss albino mice of either sex weighing around 25 - 30 g were randomly divided into six groups with six in each group. Antihistamines such as chlorpheniramine maleate (CPM), ebastine, and fexofenadine were administered to respective groups through oral route. Their effects on CNS were evaluated using rotarod and actophotometer. The data were analyzed using statistical methods. Results: CPM produced significant reduction (P < 0.05) in motor coordination and spontaneous locomotor activity. Ebastine does not have any effect on motor coordination but significant reduction (P < 0.05) in spontaneous locomotor activity. Fexofenadine does not have any effect on motor coordination and spontaneous locomotor activity. Conclusion: We conclude that CPM has significant CNS depressant actions, ebastine has minimal CNS depressant actions, and fexofenadine does not have CNS depressant actions.
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Objective To investigate the effects of a highly selective dopamine D4 receptor (ABT-724)on behaviors in Spontaneously hypertensive rats (SHR),a rat model of attention-deficit hyperactivity disorder (ADHD).Methods After intervention of methylphenidate(5mg/kg) and three different doses of ABT-724(0.04mg/kg,0.16mg/kg,0.64mg/kg),behaviors of SHR were verified by open-field test,Morris water maze and Làt maze.Results Number of square crossing after intervention of methylphenidate and ABT-724 in SHR( 70.67 ± 8.59,76.50 ± 10.75,79.17 ± 10.44,65.67 ± 20.62) was less than the saline control group( 130.33 ± 1 1.40) (P＜0.05).During Morris water maze,SHRs(52.50 ± 4.04,52.17 ± 2.99,61 ± 8.15,53.83 ± 9.87 ) after intervention of both had a better spatial memory ability than control group(38.83 ±7.17) (P＜0.05).In Làt maze,number of rearing after intervention of both in SHRs(57.17 ± 5.67,60.83 ± 8.28,55.17 ± 9.45,65.33 ± 9.50 ) was less than saline control group(78.00 ± 13.84) (P＜0.05).Conclusion ABT-724 could improve behaviors of spontaneous locomotor activity,cognitive ability,non-selective attention in SHR.
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Amitraz (AM) and romifidine (RMF), two alpha-2 adrenoceptor agonists, produce sedative effect and decrease spontaneous locomotor activity (SLA) of horses. The behavioral effects and sedation after intravenous injection of RMF (0.06mg/kg) or AM 0.1mg/kg (AM 0.1) or AM 0.4mg/kg (AM 0.4) were compared in horses. RMF caused head ptosis (HP) until 45 min. The lower AM dose induced HP from 45 to 60 minutes and from 120 to 150 minutes, and the higher dose induced HP until 180 minutes. Data concerning changes in SLA were not conclusive. RMF or AM 0.4 caused a greater sedation than AM 0.1 until 20 min. After 20 minutes, the sedation caused by AM 0.4 was greater than that of RMF or AM 0.1. Romifidine caused consistent sedation until 45 minutes. The amitraz emulsion produced a dose-dependent sedation until 180 minutes. Comparing to romifidine, the emulsion of amitraz induced a more substantial sedation. At dosages and dilution applied, amitraz is an effective sedative for horses.
Os agonistas de receptores adrenérgicos do tipo alfa-2 amitraz (AM) e romifidina (RMF) produzem efeito sedativo e reduzem a atividade locomotora espontânea (ALE) em eqüinos. Compararam-se os efeitos sedativos e comportamentais da injeção intravenosa de RMF (0,06mg/kg) ou AM 0,1mg/kg (AM 0,1) ou 0,4mg/kg (AM 0,4) em cavalos. RMF provocou ptose de cabeça (PC) por 45 minutos. O amitraz provocou PC entre 45 e 60 e entre 120 e 150 minutos com a dose menor, e por 180 minutos com a dose maior. Os dados relacionados à ALE não foram conclusivos. RMF ou AM 0,4 causaram sedação mais intensa que AM 0,1 até 20 minutos. Após 20 minutos, a sedação provocada pelo AM 0,4 foi mais intensa que para a RMF ou o AM 0,1. A romifidina causou sedação por 45 minutos. A emulsão de amitraz provocou sedação dose-dependente por 180 minutos. Em relação à romifidina, o amitraz produziu uma sedação mais consistente. Nas doses e na diluição aplicada, o amitraz é eficaz como sedativo para cavalos.
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Animals , Antipsychotic Agents/adverse effects , Adrenergic Agonists/adverse effects , Motor Activity , EquidaeABSTRACT
Spontaneous locomotor activity is a widely used evaluation method in safety pharmacology of central nerve system and investigation of neuroscience.Spontaneous locomotor activity test is an important method that can investigate several animals' species and their associated indexes of spontaneous locomotor activity;it can also provide parameters for several pharmacological objectives including safety pharmacology of central nerve system.The new developed equipments and methods have many merits.This paper reviews the progress of methodology of spontaneous locomotor activity test in rats,pigs and monkeys.
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To compare the anxiolytic effects of reduced metabolite of progesterone and benzodiazepine.Methods The effects of allopregnanolone and diazepam on spontaneous locomotor activity and on exploration in the elevated plus-maze were studied in C57 mice 20 min after vehicle or drug intraperitoneal administration.Results Allopregnanolone (0.1 mg.kg-1,ip) elicited marked anxiolytic effects in terms of significantly reducing the latency to enter the open arm from (31.30±8.39)s to (8.80±6.00)s,(P<0.001),and significantly increasing both the number of open arm entries from 1.20 ± 0.42 to 4.80 ±1.75,(P<0.001) and the proportion of total time spent on the open arm from 7.13％ to 32.50％,(P<0.001).Meanwhile,the diazepam (0.25 mg·kg-1) produced a lower anxiolytic effect comparing to that of the allopregnanolone.Analysis of spontaneous locomotor activity showed while 0.5 mg·kg-1 of diazepam decreased the locomotor activity (P<0.01),neither 0.1 mg·kg-1 of allopregnanolone nor 0.25 mg·kg-1 of diazepam affect the locomotor activity score.Conclusion Together,these results provide evidence for differential behavioral actions of the neurosteroids and benzodiazepines.Since the allopregnanolone produce a selective anxiolytic effect without affecting the spontaneous locomotor activity,the allopregnanolone may be a better alternative for diazepam in treating anxiety.
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Aim To compare the anxiolytic effects of reduced metabolite of progesterone and benzodiazepine.Methods The effects of allopregnanolone and diazepam on spontaneous locomotor activity and on exploration in the elevated plus_maze were studied in C57 mice 20 min after vehicle or drug intraperitoneal administration. Results Allopregnanolone (0.1 mg?kg-1, ip) elicited marked anxiolytic effects in terms of significantly reducing the latency to enter the open arm from (31.30?8.39)s to (8.80?6.00)s, (P