The effects of psychotropic drugs on the cholinergic and adrenergic system

Pharmacological studies on tandamine hydrochloride, a potential heterocyclic antidepressant

Tandamine, a potential heterocyclic antidepressant, was compared with imipramine for its ability to modify: (a) the contractions induced by noradrenaline (NA) and 5-hydroxytryptamine (5-HT) on the normal and chronically denervated nictitating membrane of the cat, (b) the neuron blocking effect induced by guanethidine in the guinea pig vas deferens, (c) the electroencephalograph and the physostigmine arousal in the rabbit and (d) the sleep pattern of the rat. Both tandamine and imipramine potentiated the NA and 5-HT induced contractions of the normalnictitating membrane and antagonized the effects of gaunethidine on the vas deferens. The potentiation by tandamine and imipramine of the NA and 5-HT contraction of the nictitating membrane disappeared after chronic denervation of the membrane. These results are consistant with the ability of the substances to block the neural uptake of catechol- and indoleamines. Tandamine did not induce EEG synchronization and did not affect the arousal reaction induced by physostigmine. Tandamine also reduced or abolished REM (rapid eye movement) sleep with a concomitant decrease in NREM (non-rapid eye movement) sleep.

The effects of perphenazine on self-administration behavior

In Experiment 1.6 rhesus monkeys prepared with intravenous catheters responded on a fixed-ratio 10 schedule for either an injection of 0.2 mg/kg of cocaine or 0.5 mg/kg of pentobarbital during a daily 3 hr session. The substitution of saline or various doses of perphenazine resulted in very low rates of responding. These results indicate that perphenazine is not a positive reinforcer. Pretreating animals maintained on 0.1 mg/kg or 0.2 mg/kg of cocaine with perphenazine resulted in increases in rate of self-administration at some doses and a decrease in rate at higher doses. The dose of perphenazine which resulted in the maximal increase in cocaine self-administration was directly related to the dose of cocaine maintaining responding. Pretreating animals maintained on 0.5 mg/kg of pentobarbital with perphenazine had no effect at doses which increased cocaine self-administration but decreased rate of pentobarbital self-administration at higher doses. These results indicate that perphenazine is capable of antagonizing some of the effects of cocaine.

Effect of morphine antagonists on drug-induced hypothermia in mice and rats

Since it has been reported that the narcotic antagonist analgesic, cyclazocine, has thymoleptic activity in man, certain neuropharmacological properties of this compound have been retrospectively analysed in rodents using diprenorphine, naloxone and RX 336-X 336-M (7,8-dihydro-5',6'-dimethylcyclohex-5'-eno 1',2',8',14 codeinone) as reference narcotic antagonists and morphine, desmethylimipramine and d-amphetamine as standard psychotropic agents. From interactional studies with alpha-methylparatyrosine (alpha-MT) in rats, and apomorphine, oxotremorine or reserpine in mice, the calorigenic activities of each compound were compared. Diprenorphine, naloxone and morphine (each at doses ranging from 1-30 mg/kg, s.c.) had no significant calorigenic effect in any test. Evidence of potential antidepressant activity for cyclazocine was based on a high dose (30 mg/kg, s.c.) preventing the development of reserpine-induced hypothermia. RX 336-M (0.5-16 mg/kg, s.c.) reversed established hypothermia in the reserpine and alpha-MT tests. Since this calorigenic action was not antagonised by naloxone it was concluded that narcotic receptors were probably not involved in the mediation of the effect. Although RX 336-M resembled desmethylimipramine and d-amphetamine in the reserpine (reversal) and apomorphine tests, contrasting data from the reserpine (prevention), oxotremorine and alpha-MT tests indicated possible psychotropic activity based on different neurochemical mechanisms.