AMT catalepsy and hypokinesia: interaction with morphine and cocaine

L-NAME precipitates catatonia during ethanol withdrawal in rats

The effect of N(G)-nitro-L-arginine methyl ester (L-NAME), a non-specific inhibitor of nitric oxide (NO) synthase, on catatonia in ethanol dependent rats was investigated. Ethanol was given to rats by a modified liquid diet. An isocaloric liquid diet without ethanol was also given to control rats. L-NAME (50, 100 and 200 mg/kg) and saline were injected intraperitoneally to ethanol-dependent rats 30 min before ethanol withdrawal. Then, catatonia was evaluated by vertical wire test at the 30th min, 2nd, 4th and 6th h of ethanol withdrawal. The injections were repeated 30 min before the observation of 6 h. Locomotor activity was also recorded for 5 min in the same observation intervals. L-NAME (200 mg/kg) or saline were also injected to ethanol non-dependent control rats. L-NAME (50 and 100 mg/kg) inhibited both incidence and intensity of the audiogenic seizures which appeared at 6 h of ethanol withdrawal. L-NAME (200 mg/kg) produced a significant augmentation in both incidence and intensity of the catatonia in ethanol dependent rats. This dose of L-NAME also reduced the locomotor activity of both ethanol dependent and non-dependent rats. The locomotor inhibitory effect was more prominent in ethanol-dependent group. The catatonia precipitating effect of L-NAME was not prevented by L-arginine (1 g/kg, i.p.), a NO precursor, pretreatment. In the naive rats, L-NAME also did not produce catatonia. These results indicate that L-NAME has a catatonia precipitating effect during ethanol withdrawal in rats and this effect seems to be independent from NO mediated mechanisms.

Effects of bromocriptine and haloperidol on ethanol withdrawal syndrome in rats

The effects of bromocriptine and haloperidol, either alone or in combination, on ethanol withdrawal syndrome (EWS) have been investigated in rats. Bromocriptine (5 mg/kg 1P) inhibited wet dog shakes behavior and catatonia but potentiated the intensity of abnormal gait. The latency of the audiogenic seizures was prolonged by bromocriptine treatment. Haloperidol (0.5 mg/kg SC) decreased the intensity of stereotyped behavior but potentiated catatonia and agitation. It did not antagonize the behaviors induced by bromocriptine when injected in combination except the increased latency of the audiogenic seizures. The total intensity score of the EWS was not significantly different from that in untreated control. The results suggest that brain dopaminergic system may be involved to a limited extent in mediating the EWS in rats.

Morphine may not produce true catalepsy

Though catalepsy is one of the primary features classically associated with morphine injections in animals, several investigators have suggested that morphine may not produce true catalepsy. A study was therefore undertaken using the most widely accepted tests of catalepsy to determine whether a dose related catalepsy could be obtained in rats. The effect produced by morphine was then compared with the catalepsy elicited by subthreshold to suprathreshold doses of haloperidol. In the course of catalepsy assessment, it was found that half the tests employed could not distinguish between the several doses of morphine that were administered. Moreover, the cataleptoid behavior induced by morphine failed to satisfy nearly all of the criteria most widely used for catalepsy. This is in marked contrast to the results obtained with varying doses of haloperidol. These results are compatible with the suggestion that morphine may not be a true cataleptigenic agent.

Changes in body temperature after administration of adrenergic and serotonergic agents and related drugs including antidepressants

This survey, the third in a series, presents extensive tabulations of literature, primarily since 1965, on thermoregulatory effects of adrenergic and serotonergic agonists and their antagonists including ergot alkaloids, amphetamines, tryptamines, monoamine oxidase inhibitors, tricyclic and other antidepressants, a variety of other agents which alter presynaptic aminergic mechanisms including reserpine, 6-hydroxydopamine, p-chlorophenylalanine, alpha-methyltyrosines, cocaine, guanethidine and bretylium. The information listed includes the species used, route of administration and dose of drug, the environmental temperature at which the experiments were performed, the number of tests, the direction and magnitude of body temperature change and remarks on the presence of special conditions, such as age or lesions, or on the influence of other drugs, such as antagonists, on the response to the primary drug.

Changes in body temperature after administration of acetylcholine, histamine, morphine, prostaglandins and related agents

This survey, the second in a series, presents extensive tabulations of literature, primarily since 1965, on thermoregulatory effects of cholinergic agonists and antagonists, histamine and H1- and H2-receptor antagonists, narcotic analgesics and antagonists in both non-tolerant and tolerant subjects and of prostaglandins and related agents. The information listed includes the species used, route of administration and dose of drug, the environmental temperature at which the experiments were performed, the number of tests, the direction and magnitude of body temperature change and remarks on the presence of special conditions, such as age or lesions, or on the influence of other drugs, such as antagonists, on the response to the primary drug.