Biomedical subjects
J S Morley
Publications and source records attributed to J S Morley.
Differential inhibition of hepatic morphine UDP-glucuronosyltransferases by metal ions.
The major metabolites of morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), possess significant pharmacological properties. Whilst both metabolites bind to mu-opioid binding sites, M6G is a potent agonist whereas M3G antagonizes some of the effects of morphine and M6G. An inter-species comparison of in vitro hepatic morphine processing was performed. The results showed that not all species were able to produce M6G whereas all those tested did produce M3G. Guinea-pig liver produced the greatest amounts of M6G and was therefore chosen as a model to study morphine glucuronidation in further detail. Inclusion of the detergent Brij 58 (0.33 mg/mg protein) and Mg2+ (15 mM) in the standard assay incubation gave optimal production of both M3G and M6G by guinea-pig liver homogenates. A number of metal ions were investigated for their ability to inhibit glucuronidation of morphine in both the 3- and 6-positions. Some metal ions, namely Cu+, Cu2+ and Cd2+, were able to inhibit the production of M3G without affecting glucuronidation at the 6-position. Taken together, these data provide further evidence for the existence of UDP-glucuronosyltransferase isoenzymes responsible for the metabolism of morphine. In addition these isoenzymes can be differentially modulated and therefore it is possible to alter the ratio of M3G:M6G formed during in vitro metabolic studies.
CSF enkephalins in diabetic neuropathy.
CSF methionine and leucine enkephalins were measured by high performance liquid chromatography and radioimmunoassay in diabetic patients with painful neuropathy (n = 22) and painless neuropathy (n = 5), and non-diabetic subjects with low back pain (n = 11). Wide variations in CSF enkephalin levels were found and they were often below the limit of detection (less than 0.1 pmol/l) in the diabetic and non-diabetic groups. The origin of CSF enkephalins is unknown and CSF levels may not reflect tissue concentrations. In conclusion, CSF enkephalin levels are difficult to interpret and do not provide useful information on the function of enkephalinergic pathways.
Melanotropin potentiating factor is the C-terminal tetrapeptide of human beta-lipotropin.
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Enkephalin analogues eliciting analgesia after intravenous injection.
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Analgesia following intravenous administration of enkephalin analogues [proceedings].
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Recovery of tellurite resistance by heat injured Streptococcus faecalis.
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Synthesis and biological activity of alpha-azapeptides: alpha-aza-analogues of luteinizing hormone releasing hormone.
The term "alpha-azapeptides" is applied to analogues derived by change of one or more of the alpha-CHs of amino-acid residues in peptides by N; in such analogues the overall polarity of the molecule and the spacing of side-chain residues is preserved, but stability towards peptidases may be increased because of the changed conformational situation at the residue or residues involved in the change. Three alpha-aza-analogues of LHRH, i.e. azaglycine6-, azalanine6-, and azaglycine10-LHRH, and two alpha-aza-analogues, of des-His-LHRH, i.e. azaglycine6- and azalanine3-des-His-LHRH, were prepared. The three alpha-aza-analogues of LHRH were as active as LHRH in inducing ovulation in androgen-sterilized, constant-oestrus rats, but less potent than LHRH in causing LH release in immature male rats. Evidence of increased duration of action was not obtained. The two aza-analogues of des-His-LHRH were neither agonists nor antagonists in these two test systems.
Polypeptides. Part XIII. Preparation of alpha-aza-amino-acid (carbazic acid) derivatives and intermediates for the preparation of alpha-aza-peptides.
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