Two experiments were carried out using a fixed ratio (FR) schedule of water reinforcement to determine the efficacy of two serotonin (5HT) depleting agents (p-chloroamphetamine, 5, 7-dihydroxytryptamine) in altering sensitivity to a low dose of LSD (0.02 MG/KG). The results showed that while both p-chloroamphetamine (PCA) and 5, 7 dihydroxytryptamine (5, 7 DHT) were efficacious in reducing...
Lysergic acid diethylamide (LSD), 0.05 mg/kg and 0.20 mg/kg, significantly decreased plasma prolactin (PRL) levels in male rats. LSD, 0.20 mg/kg, also inhibits the increase in plasma PRL levels produced by chlorpromazine (CPZ), 5 mg/kg, and alpha-methylparatyrosine (AMPT), 50 mg/kg, both of which interfere with dopaminergic inhibition of PRL secretion. LSD was more potent than methysergide, a...
LSD administration in rats elicited a diphasic reaction consisting of a brief excitable period ( up to 8 min) followed by a prolonged catalepsy (8 min-1 h). While the cataleptic response was antagonized by a single injection of naloxone (given 30 min after LSD administration), pretreatment with naloxone shortened the excitable phase and potentiated the catalepsy.
At a dose as low as 1 microgram per kilogram of body weight, lysergic acid diethylamide (LSD) significantly decreased the suppressive effect of electric shock on licking behavior of the rat. Attenuation of punishment was also obtained with mescaline, but neither dimethyltryptamine nor Δ 9 -tetrahydrocannabinol was active in this test. Cyproheptadine and α-propyldopacetamide, drugs that...
Helen Rosengarten, M.D., Arnold J. Friedhoff, M.D.; A Review of Recent Studies of the Biosynthesis and Excretion of Hallucinogens Formed by Methylation of Neuro
The effects of lysergic acid diethylamide (LSD) and apomorphine were compared using female copulatory behavior (lordosis response), in ovariectomized estrogen + progesterone-treated rats. Both serotonin and dopamine are implicated in the inhibition of this behavior. Each compound inhibited lordosis behavior dose dependently and with a similar time-course. Pimozide (0.1; 0.5 mg/kg) blocked the...
Acute parachlorophenylalanine (pCPA) pretreatment (150 mg/kg, i.p., 24 h beforehand) potentiated facilitatory effects of mescaline (39.6 mg/kg i.p.) on shuttlebox escape/avoidance in hooded rats, tested in two different situations: 1. during aquisition of avoidance behavior (Experiment 1); and 2. in stable pretrained poor avoiders (Experiment 2). pCPA alone did not influence avoidance behavior...
Investigations were carried out on the interactions of the hallucinogenic drug, D-lysergic acid diethylamide (D-LSD), and other serotonin antagonists with catecholamine-sensitive adenylate cyclase systems in cell-free preparations from different regions of rat brain. In equimolar concentration, D-LSD, 2-brono-D-lysergic acid diethylamide (BOL), or methysergide (UML) strongly blocked maximal...
Recordings of the electroencephalogram (EEG) and the electromyogram (EMG) were collected continuously from rats equipped with permanent cortical and temporalis muscle electrodes. Automatic injections of mescaline were administered through indwelling i.p. cannulas at an initial dose of 30 mg/kg every 6 hrs for the first 2 days. This dose was then increased to 60 mg/kg 6 hr which was given for...
D-lysergic acid diethylamide (LSD) displays (1) the phenylethylamine pattern present in mescaline, cyclazocine and catecholamines and (2) the 4-substituted tryptamine structure of psilocybin which is a serotonin analog. Hence (a) Naloxone--a blocker of the LSD-like side effects of cyclazocine--should (and does) block effects of LSD, and (b) cross-tolerance may be present between LSD and...