Behavioural and electrocortical power spectrum effects of 5-methoxytryptoline and other analogs after intraventricular administration in rats.
The behavioural and electrocortical power spectrum effects of tryptoline and the 5-hydroxy and 5-methoxy derivatives were studied after microinjection of the drugs into the third cerebral ventricle in freely moving rats. The three compounds produced a dose-dependent desynchronication in electrocortical activity with a concomitant syndrome of behavioural stimulation. The most potent compound was 5-methoxytryptoline, already active at 4 nmol. When given into the third cerebral ventricle, 5-methoxytryptoline antagonized the sedation and hypothermia induced by reserpine. The relative order of potencies was 5-methoxytryptoline greater than 5-hydroxytryptoline greater than tryptoline. Melatonin, the 5-methoxy-N-acetyl derivative of serotonin, when injected into the third cerebral ventricle, did not produce desynchronization and elicited only mild sedation. The high potency of 5-methoxytryptoline following injection into the third cerebral ventricle and the relative order of potencies with 5-hydroxytryptoline and tryptoline is compared to the affinity of these compounds for the modulatory site of the serotonin transporter which was labelled with [3H]imipramine or [3H]paroxetine.
Institute of Pharmacology, Faculty of Medicine, Catanzaro, Italy.
G
G
Nistico
G B
GB
De Sarro
S Z
SZ
Langer
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D002243:Carbolines / Q000008:administration & dosage / Q000494:pharmacology*; D004347:Drug Interactions; D004569:Electroencephalography; D006993:Hypnotics and Sedatives; D007276:Injections, Intraventricular; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012110:Reserpine / Q000494:pharmacology
D002243:Carbolines; D006993:Hypnotics and Sedatives; C045647:5-methoxytryptoline; D012110:Reserpine; D008550:Melatonin