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Biomedical subjects

M P Caton

Publications and source records attributed to M P Caton.

12 recordsLinked to original sources
PubMed2000

Comparative action of carbocyclic thromboxane A(2) stereoisomers on platelets.

Stereospecific requirements for the interaction of the thromboxane A(2) carbocyclic mimetic CTA(2) 1 with the human platelet PGH(2)/TXA(2) receptor have been explored. The two pairs of trans-1,2 and cis-3,4 side chain diastereoisomers were synthesised and evaluated for agonist and antagonist activity in human platelet rich plasma. Interestingly, the natural and unnatural trans diastereoisomers, both possessed potent aggregatory activity and equipotently inhibited platelet responses to subsequent addition of agonists, whereas, the respective unnatural cis isomers proved only weakly active or inert.

Blood Platelets↗
PubMed1984

Uterine stimulant action of some 16-phenoxy analogues of (+)-11-deoxyprostaglandin E1.

Some (+)-11-deoxy-16-phenoxyprostaglandin E1 analogues have been evaluated as uterine stimulants in the anaesthetised pregnant rat. Gastrointestinal side effects, assessed by the antagonism of morphine-induced constipation in the mouse, were relatively low with some of these compounds, six of which had a much more favourable relative selectivity than 16,16-dimethyl-PGE2 methyl ester.

Alprostadil↗
PubMed1981

Uterine stimulant action of some omega-chain modified (+)-11-deoxyprostaglandins.

Rat uterine stimulant activity has been determined in vivo for a series of (+)-11-deoxyprostaglandins. The most active members of the series. 11-deoxy-15 methyl-PGE1, 11-deoxy-16,16-dimethyl - PGE1 and its 1-alcohol were 2-3 times more potent than PGE1. Gastrointestinal side effects assessed by the antagonism of morphine-induced constipation in the mouse, were generally relatively low with these compounds and consequently several members of the series had a more favourable relative selectivity than 16,16-dimethyl-PGE2 methyl ester.

Animals↗
PubMed1980

Synthesis and antifertility activity of omega-chain phenyl- and 16-phenoxy-analogues of (+/-)-11-deoxyprostaglandin F1 alpha.

Some omega-chain phenyl- and 16-phenoxy- analogues of (+/-)-11-deoxyprostaglandin F1 alpha have been synthesized and evaluated for anti-fertility activity in the hamster. 11-Deoxy-16-phenoxy-17,18,19,20-tetranor-PGF1 alpha was the most active member of the series with an ED50 equal to that of PGF2 alpha. 11-Deoxy-17-phenyl-18,19,20-trinor-PGF1 alpha, which was one third as active as PGF2 alpha, was more potent than the corresponding 16- and 18-phenyl compounds. Aryl ring substitution was found to lower activity, except that with the 16-phenyl compound, p-bromo and m-trifluoromethyl substitution increased the potency. The antifertility activity of the phenoxy compounds, which were poor substrates for 15-hydroxyprostaglandin dehydrogenase, was shown to correlate well with the binding affinity for the bovine corpus luteum PGF2 alpha receptor. Some quantitative structure-activity data supporting this finding are presented.

Animals↗
PubMed1979

Prostaglandins V (1). Synthesis and pharmacology of (+/-)-11-deoxy-10-hydroxyprostaglandin E1 methyl ester.

(+/-)-Deoxy-10-hydroxy-PGE1 methyl ester (Va) has been synthesised via conjugate addition of the cuprate (III) to the 5-tetrahydropyranyloxycyclopentenone (IId). Va was found to be 0.1 times as active as PGE1 as a uterine stimulant in the anaesthetized pregnant rat, 0.25 times as active as PGE1 in causing vasodepression in the anaesthetized cat, and approximately equiactive to PGE1 in inducing bronchoconstriction.

Alprostadil↗
PubMed1978

Synthesis and gastrointestinal pharmacology of some 15- and 16- modified (+/-)-11-deoxyprostaglandins.

The synthesis and gastrointestinal pharmacology of some 11-deoxyprostaglandin E1 analogues are described with results analysed for selectivity from side effects. 11-Deoxygenation reduced potency relative to PGE2 but, as has been reported for natural PGs, 15- or 16-methyl analogues were more potent than the unsubstituted parent compound in the order 16-methyl greater than 15-methyl greater than 16,16-dimethyl. The results suggest that a complex interaction between C-15 and C-16 in methyl analogues affects their profile of activity, but that none of the modifications studied conferred a substantial potency or selectivity advantage over PGE2.

Animals↗