eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2019-09-25 12 3 1339 1343 10.13005/bpj/1762 28413 article Vandana Milind Thorat 1 Chitra C Khanwelkar 1 Somnath Mallikarjun Matule 1 Pratibha Satish Salve 1 Smita Ajit Surle-Patil 1 Seshla Sadanandan 1 Department of Pharmacology, Krishna Institute of Medical Sciences Karad. Activation of central brain serotonergic receptors viz 5-HT_1A and 5-HT_2A by serotonin (5-HT) induces the 5-HT behavioural syndrome in rats. 5-HTP and dexfenfluramine produce 5-HT mediated behaviours. We have carried out the experiment with the aim to study the effect of duloxetine pretreatment on 5-hydroxytryptophan and dexfenfluramine induced behaviours in albino rats. Pre-treatment with 20 mg/kg duloxetine, a SNRI was found to potentiate 75 mg/kg 5-HTP mediated behavioural syndrome. However, 5, 10 and 20 mg/kg duloxetine had decreased the intensity of the behavioral syndrome produced by 10 mg/kg dexfenfluramine significantly. Duloxetine at 5, 10 and 20 mg/kg had produced inhibition of serotonin transporter (SERT) and inhibited dexfenfluramine uptake which had significantly antagonised its behavioural syndrome. Duloxetine at 5 and 10 mg/kg did not affect 5-HTP induced behavioral syndrome significantly where as 20 mg/kg duloxetine did significantly potentiate 5-HTP induced behavioral syndrome. This indicates 20 mg/kg dose of duloxetine blocks neuronal reuptake of 5-HT by blocking SERT and effectively increase its concentration to greater level in the synaptic gap which causes synergistic stimulation of the central postsynaptic 5-HT_1A and 5-HT_2A receptors and potentiation of 5-HTP behavioral syndrome. https://biomedpharmajournal.org/vol12no3/effect-of-duloxetine-pretreatment-on-5-htp-and-dexfenfluramine-induced-behaviours-in-albino-rats-2/ Behavioural Syndrome Duloxetine Dexfenfluramine 5-Htp