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Biomedical subjects

B J Pleuvry

Publications and source records attributed to B J Pleuvry.

At least 73 records · Page 4Linked to original sources
PubMed1976

A comparison of the effects of morphine and pethidine upon body temperature and the reversal of reserpine's effects upon body temperature in the mouse.

The effects of morphine and pethidine upon body temperature and upon the reversal of reserpine hypothermia in the mouse were investigated. Both morphine and pethidine produced a dose-dependent fall in body temperature, that of morphine being totally antagonized by nalorphine and partially by naloxone, while that of pethidine was antagonised by naloxone and enhanced by nalorphine. Both drugs reversed reserpine-induced hypothermia. The reversal by morphine, but not by pethidine, was partially antagonized by naloxone. Adrenalectomy prevented the reversal of reserpine hypothermia by pethidine but morphine produced a partial reversal. Ganglion blockade and alpha-and beta-blockade all prevented reversal of reserpine hypothermia by both drugs. The results are discussed with regard to differences between pethidine and morphine and possible involvement of opiate receptors.

Adrenalectomy↗
PubMed1975

Mouse brain catecholamines, 5-hydroxytryptamine and the antinociceptive activity of pethidine.

The involvement of brain 5-hydroxytryptamine (5-HT), noradrenaline and dopamine in the antinociceptive activities of pethidine and morphine has been compared in the mouse. Differences have been shown in the activities of pethidine and morphine in mice treated with either 5-hydroxytryptophan or reserpine. No differences between the activities of pethidine and morphine were demonstrated in mice treated with either alpha-methyl-p-tyrosine, L-dopa or p-chlorophenylalanine. In reserpinised mice, pethidine's antinociceptive activity was either potentiated, unaffected or antagonised, dependent upon the reserpine dose schedule. Pethidine was shown to be able to raise brain 5-HT concentrations in reserpinised mice. This effect was also dependent upon the reserpine dose schedule used. Morphine, which was antagonised by all reserpine dose schedules, did not raise noradrenaline or dopamine in control or reserpinised mice. Although the reserpine schedule, which potentiated pethidine's antinociceptive activity, was the same as that in which pethidine had the most marked effects upon 5-HT, no definite connections between the two observations could be made. Naloxone abolished the antinociceptive activity of pethidine in reserpinised mice, but not the rise in 5-HT.

Analgesics↗
PubMed1975

Benzoctamine-a study of the respiratory effects of oral doses in human volunteers and interactions with morphine in mice.

A double-blind trial has been performed to investigate the respiratory effects of low oral doses of benzoctamine, and to compare them with diazepam and a placebo. The displacement of the carbon dioxide response curves indicated that whilst diazepam caused respiratory depression, benzoctamine had a variable effect. Some volunteers showed depression, but most showed stimulation. Peak respiratory effects were seen 1 hr after oral administration, returning to normal 2-3 hr after administration. It is suggested that oral drugs given for premedication need to be administered at least 2 hr before operation to obtain maximum sedative effects at a time when respiratory effects are returning to normal. In animal experiments it has been shown that the analgesic actions of morphine are diminished by concurrent administration of benzoctamine, and that the depression of respiratory rate caused by morphine is enhanced.

Administration, Oral↗
PubMed1974

The cardiovascular effects of ergometrine in the experimental animal in vivo and in vitro.

The cardiovascular effects of ergometrine have been examined using animal models in vivo and in vitro. In rats in vivo the pressor effects of a standard dose of ergometrine were found to be dependent upon the anaesthetic used for the procedure. The pressor action of ergometrine was greater when urethane, an anaesthetic which produces both sympathetic and parasympathetic acitivity, was used. The in-vitro experiments, using isolated rabbit aorta and portal vein, failed to explain the phenomenon; they suggested that ergometrine has a direct action on the alpha-adrenoceptor in rabbits. No evidence was found to suggest that ergometrine inhibits noradrenaline uptake or its release from the nerve terminals.

Anesthetics↗
PubMed1971

Effects of alpha-methyl-p-tyrosine, p-chlorophenylalanine, l-beta-(3,4-dihydroxyphenyl)alanine, 5-hydroxytryptophan and diethyldithiocarbamate on the analgesic activity of morphine and methylamphetamine in the mouse.

1. The analgesic activity of sympathomimetic drugs does not appear to involve a peripheral component.2. Drugs causing changes in morphine analgesia have similar effects on the analgesia produced by methylamphetamine.3. The analgesia produced by morphine and methylamphetamine is increased by drugs which increase the ratio of brain 5-hydroxytryptamine (5-HT) to dopamine.4. The analgesia is decreased by drugs causing a fall in brain 5-HT or a rise in dopamine relative to 5-HT.

5-Hydroxytryptophan↗
PubMed1971

Comparison of the antinociceptive activities of physostigmine, oxotremorine and morphine in the mouse.

1. Morphine, oxotremorine and physostigmine showed antinociceptive activity in mice using the hot plate reaction time test.2. The action of morphine, but not that of oxotremorine, was antagonized by naloxone and by nalorphine, whereas the effect of physostigmine was unaffected by naloxone and increased by nalorphine.3. The antinociceptive effects of morphine and of physostigmine were increased by procedures reported to increase the ratio of 5-hydroxytryptamine to dopamine in the brain. It was decreased by procedures reported to cause a fall in brain 5-hydroxytryptamine or a rise in dopamine relative to 5-hydroxytryptamine.4. The antinociceptive effect of oxotremorine was potentiated by procedures reported to decrease brain noradrenaline and was unaffected by procedures altering brain 5-hydroxytryptamine.5. The results suggest differences in the mode of action of morphine and physostigmine on the one hand and of oxotremorine on the other.

5-Hydroxytryptophan↗