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M D Hammond

Publications and source records attributed to M D Hammond.

29 records · Page 2Linked to original sources
PubMed1982

Selective inhibition by betamethasone of allergen-induced release of SRS-A from human lung.

Passively sensitized human lung, when incubated with the appropriate allergen, released histamine and slow-reacting substance (SRS-A). Betamethasone sodium phosphate (5-100 microgram/ml), preincubated with the lung overnight, suppressed, in a dose-related manner, the release of SRS-A without having an effect on the release of histamine. Preincubation for only 1 h produced little effect on the release of SRS-A or of histamine. These results may help to explain some of the beneficial effects of glucocorticoids in allergic asthma.

Allergens↗
PubMed1977

The extraction and analysis of benzodiazepines in tissues by enzymic digestion and high-performance liquid chromatography.

A simple, rapid and sensitive method is described for the analysis of unchanged benzodiazepine drugs and their metabolites, in human and animal tissues, using the proteolytic enzyme subtilisin Carlsberg followed by reverse-phase liquid chromatography. The enzymic digestion yields far higher recoveries than conventional extraction methods, while the liquid chromatogrpahic analysis allows the rapid separation and detection of nanogram quantities of these drugs without the need for elaborate "clean-up" procedures.

Animals↗
PubMed1976

Effects of drugs affecting endogenous amines or cyclic nucleotides on ethanol withdrawal head twitches in mice.

1 Twenty-four hours after ethanol withdrawal, dependent mice exhibited frequent head twitching. Naive mice exhibited similar twitching 15 min after treatment with 5-hydroxytryptophan (5-HTP) or 6 h after alpha-methyl-p-tyrosine (AMPT). Ethanol lessened the incidence of head twitches induced by any of these treatments. 5-HTP and AMPT each increased the incidence of head twitches induced by withdrawal of ethanol from dependent mice. 2 Drugs that affect the amount or activity of endogenous amines or cyclic nucleotides modified the incidence of head twitches. Nearly all drugs acted in the same direction on twitching elicited by any of these three treatments. 3 The incidence was lessened by: (a) methysergide, methergoline, MA 1420, p-chlorophenylalanine and p-chloroamphetamine; (b) dopamine, noradrenaline, L-DOPA, amphetamine and apomorphine; (c) hyoscine and nicotine; and (d) adenosine triphosphate, dibutyryl cyclic adenosine-3',5'-monophosphate (db cyclic AMP) and prostaglandins E1 and E2. 4 The incidence was increased by: (a) acetylcholine, carbachol and physostigmine; and (b) guanosine triphosphate, dibutyryl cyclic guanosine monophosphate (db cyclic GMP), theophylline and 3-isobutyl-1-methyl-xanthine. 5 These findings suggest that head twitching induced by these three treatments arises from a common biochemical mechanism, which may ultimately be a change in favour of cyclic GMP of the balance between this nucleotide and cyclic AMP within appropriate neurones. This imbalance appears to be elicited or increased by 5-hydroxytryptamine and acetylcholine and to be decreased by dopamine, noradrenaline and E prostaglandins. 6 Neither actinomycin D nor cycloheximide, given during the induction of ethanol dependence, altered the incidence of head twitches after ethanol withdrawal.

Acetylcholine↗
PubMed1974

Biogenic amines and head twitches in mice during ethanol withdrawal.

After chronic administration of ethanol to mice by the intragastric route head twitches occur as part of the ethanol withdrawal syndrome. Treatments which reduce brain 5-hydroxytryptamine or increase brain noradrenaline inhibited ethanol withdrawal head twitches, whereas treatments which increase brain 5-hydroxytryptamine or reduce brain noradrenaline were capable of inducing head twitches in control animals.

5-Hydroxytryptophan↗