Mechanism of inhibitory effect of citalopram on isolated guinea-pig atria in relation to adenosine receptor

✍ Scribed by Abbas Pousti; Tara Deemyad; Golrokh Malihi

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 63 KB
• Volume: 19
• Category: Article
• ISSN: 0885-6222
• DOI: 10.1002/hup.593

✦ Synopsis

The effect of citalopram (CTP), a selective serotonin reuptake inhibitor antidepressant was studied on the rate and force of contractions of isolated guinea-pig atria. CTP (2-32 mg/ml) caused a dose-dependent decrease in the contractile force (7%-62%) and in the rate of contractions (11%-72%). These negative inotropic and chronotropic effects of CTP (8 mg/ml) were not prevented by atropine (1 mg/ml) and 3,7 dimethyl-1-propargylxanthine (DMPX; 1.5 mg/ml), an adenosine A 2 receptor antagonist, but 1,3 dipropargyl-8-cyclopentylxanthine (DPCPX; 12 mg/ml), a specific adenosine A 1 receptor antagonist significantly blocked these effects ( p < 0.001) and theophylline (30 mg/ml) a non-selective adenosine A 1 /A 2A receptor antagonist also prevented the inotropic and chronotropic effects of CTP. These results suggest that the negative inotropic and chronotropic effect of CTP on isolated guinea-pig atria is probably mediated through an inhibition of the uptake of adenosine or the A 1 receptor mechanism.