title: Antidepressant-like activity of flunarizine in modified tail suspension test in rats.
abstract: BACKGROUND
  Flunarizine, a Ca(2+) channel blocker, crosses blood brain barrier (BBB), antagonizes calcium influx and interferes with neurotransmitter system. Flunarizine 20 mg/kg exhibited significant antidepressant activity in our previous study using forced swim test (FST) in mice, which was contradictory to the findings of other authors. Hence, the present study was designed to strengthen the results of our previous study, using the modified tail suspension test (TST) in rats.
  
  
  OBJECTIVE
  Aim of this study was to evaluate the antidepressant activity of flunarizine versus standard antidepressant drug fluoxetine in modified TST in rats.
  
  
  METHODS
  The study approved by Institutional Animal Ethics Committee was conducted using 24 adult albino rats (n = 6 in each group). Antidepressant effect of normal saline (0.1 ml/100 g), fluoxetine (10 mg/kg, intraperitoneally (ip)), and flunarizine (2 and 10 mg/kg, ip) was evaluated by using modified TST in rats. Thirty minutes after administration of all test drugs the duration of immobility was recorded for a period of 5 min in all rats by using modified TST. The data was analyzed by Student's t-test and one-way analysis of variance (ANOVA) and P < 0.05 was considered significant.
  
  
  RESULTS
  Mean duration of immobility was significantly reduced in fluoxetine and flunarizine (10 mg/kg, ip) group as compared to the normal saline, that is, 160.33, 175.17, and 226.83 s, respectively (P < 0.05). Decrease in immobility with flunarizine (10 mg/kg, ip) was statistically significant compared with normal saline, but was not found to be significant when compared to fluoxetine (P > 0.05). Also, currently used human dose of flunarizine when extrapolated to rats (i. e., 2 mg/kg, ip) failed to show significant antidepressant effect in modified TST in rats.
  
  
  CONCLUSIONS
  The results of the present study indicate antidepressant-like activity of flunarizine.
authors.affiliation: Department of Pharmacology, Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune, Maharashtra, India.
authors.forename: Vinod
authors.initials: V
authors.lastname: Shinde
authors.affiliation: Department of Pharmacology, Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune, Maharashtra, India.
authors.forename: Radha
authors.initials: R
authors.lastname: Yegnanarayan
authors.affiliation: Department of Pharmacology, Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune, Maharashtra, India.
authors.forename: Priyank
authors.initials: P
authors.lastname: Shah
authors.affiliation: Department of Pharmacology, Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune, Maharashtra, India.
authors.forename: Ankush
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Pharmacology, Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune, Maharashtra, India.
authors.forename: Prachi
authors.initials: P
authors.lastname: Pophale
keywords: Antidepressant; Flunarizine; Fluoxetine; Tail suspension test
references.citation: Eur J Pharmacol. 1987 Jun 26;138(3):413-6
references.pmid: 3622617
references.citation: Psychopharmacology (Berl). 1986;90(2):284-5
references.pmid: 3097714
references.citation: Cephalalgia. 1990 Feb;10(1):3-8
references.pmid: 2107977
references.citation: J Neural Transm. 1984;60(3-4):169-97
references.pmid: 6241226
references.citation: J Neural Transm Gen Sect. 1991;83(3):179-88
references.pmid: 2031709
references.citation: Behav Pharmacol. 1997 Nov;8(6-7):629-38
references.pmid: 9832975
references.citation: Psychopharmacology (Berl). 1985;85(3):367-70
references.pmid: 3923523
references.citation: J Neurosci. 2004 Jun 9;24(23):5420-6
references.pmid: 15190115
references.citation: Basic Clin Pharmacol Toxicol. 2004 Feb;94(2):79-88
references.pmid: 14748851
references.citation: J Pharmacol. 1986 Jul-Sep;17(3):348-50
references.pmid: 3795979
references.citation: Biol Psychiatry. 1994 Jul 15;36(2):118-23
references.pmid: 7948444