Citalopram: a new potent inhibitor of serotonin (5-HT) uptake with central 5-HT-mimetic properties.

Citalopram (1--16 mg/kg), but not amitriptyline, clomipramine, imipramine or zimelidine, stimulated the hind limb flexor reflex in the spinal rat. This stimulatory effect was abolished by serotonin (5-HT) receptor blocking agents (cyproheptadine, metergoline) and prevented ty p-chlorophenylalanine, an inhibitor of 5-HT synthesis. Citalopram (20 mg/kg), similarly but more strongly than clomipramine (20 mg/kg), prevented both fenfluramine- and p-chloroamphetamine-induced hyperthermia in rats kept at 28 degrees C.

The effect of thyroliberin and some of its analogues on the hind limb flexor reflex in the spinal rat.

Thyroliberin (TRH) (0.5-4 mg/kg) enhanced the flexor reflex (increase in the reflex amplitude) in a dose-dependent way. A similar though weaker effect was exerted by one of its analogues examined in our experiment (Pyr-His-Pro-NH-NH2 .

Zimelidine and clomipramine: different influence on fenfluramine but not p-chloroamphetamine-induced pharmacological effects.

The influence of zimelidine and clomipramine on two p-chloroamphetamine (PCA)- or fenfluramine-induced pharmacological effects, regarded as resulting from the serotoninergic stimulation, was studied. In the flexor reflex test in the spinal rat zimelidine prevented potentiation induced by PCA but not that induced by fenfluramine. Clomipramine antagonized both the PCA- and fenfluramine-induced effects.

An evidence for the central serotoninergic activity of viloxazine.

The effects of viloxazine on the flexor reflex of the hind limb of the spinal rat and the blood pressure in the pithed rat were studied. Viloxazine (1--16 mg/kg) stimulated the hind limb flexor reflex in the dose-dependent manner. This effect of viloxazine was inhibited by serotonin receptor blockers, cyproheptadine, danitracen and metergoline, and by serotonin uptake blocking agents imipramine and clomipramine.