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Biomedical subjects

B A Spicer

Publications and source records attributed to B A Spicer.

11 recordsLinked to original sources
PubMed1979

Aryloxyalkyloxy- and aralkyloxy-4-hydroxy-3-nitrocoumarins which inhibit histamine release in the rat and also antagonize the effects of a slow reacting substance of anaphylaxis.

The syntheses and structure--activity relationships of a number of 4-hydroxy-3-nitrocoumarins, which are both antagonists of a slow reacting substance of anaphylaxis and potent inhibitors of antigen-induced histamine release in the rat, are described. Most active among these are 7-[3-(4-acetyl-3-hydroxy-2-n-propylphenoxy(-2-hydroxypropoxy] derivatives having hydrogen or lower alkyl substituents at the C-8 position of the coumarin ring, 168, 171, 173, and 174.

4-Hydroxycoumarins↗
PubMed1978

The effect of sodium 5,6-dimethyl-2-nitroindanedione on anaphylactic reactions in vitro.

A nitroindanedione (BRL 10833) inhibited the antigen induced release of histamine and slow reacting substance of anaphylaxis (SRS-A) from passively sensitized human lung at similar concentrations to those required for the inhibition of histamine release by disodium cromoglycate (DSCG). BRL 10833 was more potent than DSCG as an inhibitor of histamine release by antigen from actively and passively sensitized rat peritoneal cells and rat skin fragments.

Animals↗
PubMed1978

Peritoneal anaphylaxis in the rat after sensitization with mouse antiserum.

Passive peritoneal anaphylaxis in rats, sensitized with mouse antiserum, had characteristics of an IgE-mediated reaction, in that the serum was heat-labile and pretreatment of the rats with disodium cromoglycate (DSCG), or sodium nivimedone, inhibited the release of both histamine and slow-reacting substance of anaphylaxis (SRS-A). Sodium nivimedone was more potent than DSCG as an inhibitor of histamine release. Peak concentrations of histamine and SRS-A in the peritoneal fluids of the rats, were reached within 2 min of antigen challenge and fell to control levels after 20-30 min.

Anaphylaxis↗
PubMed1978

5-Hydroxytryptamine and rat passive peritoneal anaphylaxis.

Antigen challenge of rats, sensitized by intraperitoneal injection with rat anti-serum, did not result in a detectable increase in the 5-hydroxytryptamine (5-HT) levels in their peritoneal fluids over the background level induced by sensitisation alone. The maximum amount of extravasation produced by intraperitoneal injection of 5-HT into passively sensitised rats was less than that produced by antigen or histamine, and the doses of 5-HT producing these levels of extravasation produced an produced an increase of 5-HT concentrations in the peritoneal fluids. Therefore, 5-HT is unlikely to make much direct contribution to the extravasation produced during rat passive peritoneal anaphylaxis. However, when given intraperitoneally to rats, 5-HT potentiates the extravasation produced by histamine.

Anaphylaxis↗
PubMed1977

2-cyano-1,3-dicarbonyl compounds with antiallergic activity.

A number of 2-cyanoindan-1,3-diones and 3-cyano-4-hydroxycoumarins have been prepared and assessed for potential antiallergy activity as measured by their ability to inhibit passive cutaneous anaphylaxis in the rat, mediated by rat serum containing antigen specific IgE. The structural requirements for activity were similar not only for both series of compounds but also for the analogous 2-nitroindan-1,3-diones and 4-hydroxy-3-nitrocoumarins previously reported. The most active compounds were 2-cyano-5,6-diethylindan-1,3-dione (4e) and 3-cyano-6,7-diethyl-4-hydroxycoumarin (11h).

4-Hydroxycoumarins↗
PubMed1977

Synthesis and antiallergic activity of 2-hydroxy-3-nitro-1,4-naphthoquinones.

A selection of novel 2-hydroxy-3-nitro-1,4-naphthoquinones are shown to be potent inhibitors of rat passive cutaneous anaphylaxis (PCA) and to have highest potency with alkyl substitution at both C-6 and C-7. The most potent compounds were 7c and 7e which produced a 50% inhibition in the rat PCA test at doses of about 10 micrometerM/kg following subcutaneous administration and showed activity after oral administration. Related 4-hydroxy-3-nitro-2(1H)-naphthalenones had no effect on rat PCA in doses up to 500 micrometerM/kg.

Animals↗
PubMed1977

Further studies on passive peritoneal anaphylaxis in the rat.

Four compounds with H1 anti-histamine activity and four adrenoceptor stimulants, each given to rats prior to passive peritoneal anaphylaxis (PPA), inhibited extravasation of serum proteins into the peritoneal fluid at doses which had no effect on histamine release. In contrast, aminophylline and some non-steroidal anti-inflammatory agents inhibited extravasation only at doses which inhibited histamine releases they showed a similar type of avtivity to that of disodium cromoglycate (DSCG) and a nitroindanedione (BRL 10833), although they were much less potent. Predosing with DSCG reduced the potency of subsequent doses of DSCG, BRL 10833 and indomethacin, but not of aminophylline or phenylbutazone, and therefore DSCG, BRL 10833 and indomethacin may share a common pathway to produce activity. In the rat PPA system, no evidence was found for histamine 'feedback' inhibition of histamine release.

Adrenergic alpha-Agonists↗
PubMed1976

Increased vascular permeability during passive peritoneal anaphylaxis in the rat. The effects of disodium cromoglycate and a nitroindanedione.

Following intraperitoneal sensitisation of rats with rat serum containing reaginic antibody, intravenous injection of blue dye and intraperitoneal challenge with antigen caused a release of histamine, slow-reacting substance of anaphylaxis (SRS-A) and dye into their peritoneal fluids. The times taken to reach peak concentrations after challenge were less than 2 min for histamine and between 5 and 10 min for SRS-A, whilst concentrations of dye were still increasing after 2 1/2 h. The amounts of histamine released by antigen were sufficient to account for about 60% of this extravasation of dye. Disodium cromoglycate (DSCG) and a nitroindanedione (BRL 10833) inhibited extravasation by inhibition of mediator release. BRL 10833, unlike DSCG, was active after oral administration, and for a given inhibition of histamine release it produced a greater effect on extravasation when given orally than when injected intraperitoneally.

Administration, Oral↗
PubMed1975

Inhibition of immediate hypersensitivity reactions in the rat by disodium cromoglycate and nitroindanedione.

A nitroindanedione (BRL 10833) and disodium cromoglycate (DSCG) showed similar activities as inhibitors of IgE-mediated passive cutaneous anaphylaxis (PCA) and passive peritoneal anaphylaxis (PPA) reactions in the rat. BRL 10833 was more active than DSCG when given parenterally and unlike DSCG it inhibited the PCA reaction in the rat after oral administration. In the PCA test both compounds produced a state of refractoriness both to themselves and to each other. Isoprenaline also inhibited the PCA reaction but its activity was not reduced when the rats were refractory to DSCG.

Anaphylaxis↗