Structure-activity relationship in the effect of 1,4-benzodiazepines on morphine, aminopyrine and oestrone metabolism

The influence of a number of 1,4-Benzodiazepines was investigated on morphine and aminopyrine metabolism and on oestrone and p-nitrophenol glucuronidation, in rat liver microsomes. Benzodiazepines inhibited in a differential degree the N-demethylase activities for morphine and aminopyrine N-demethylation as well as glucuronyltransferase activity for morphine. Oestrone glucuronyltransferase activity was markedly stimulated by certain benzodiazepines whereas p-nitrophenol glucuronidation was not altered. A structure activity relationship in the inhibition of morphine and aminopyrine metabolism by benzodiazepines was observed. In fact, the presence of halogens at C-2, a methyl group at N-1 and a methylene substituent instead of a keto group at C-3 in the benzodiazepine structure increased the inhibitory effect. The possible role of these metabolic pathways of other substituents in the benzodiazepines, is discussed.

[The fuzzy set theory as a biomedical diagnostic aid (author's transl)]

In this paper, the theory of fuzzy sets and fuzzy logic is approached as a diagnostic aid for practitioners and biologists. A few theoretical considerations are followed by two practical applications. The first is a modification of the WHO-Fredrickson classification of hyperlipoproteinemias, with the introduction of secondary or minor types corresponding to everyday medical practice. The other is an attempt at classifying the four most prevalent anemias encountered in internal medicine. Recent studies have shown that the various parameters should be grouped on a hierarchical basis.

Differential inhibition by diazepam and nitrazepam of UDP-glucuronyltransferase activities in rats

To assess the role of the N-alkyl group in the interaction of N-alkylated compounds on UDP-glucuronyltransferases, the effect of diazepam and nitrazepam, an N-desmethyl derivative of the diazepam class was studied on morphine, p-nitrophenol and testosterone glucuronidation in rats. Diazepam competitively inhibited the UDP-glucuroyltransferase activity for morphine in hepatic microsomes. The k value for morphine was 0.3 mM and the Ki for diazepam was about 0.23 mM. Also, diazepam administration to male rats reduced the glucuronyltransferase activity for morphine in rat hepatic microsomes in a dose effect relationship. Nitrazepam had no significant effect on morphine UDP-glucuronyltransferase activity in vitro or in in vivo experiments. Neither diazepam nor nitrazepam produced any effect on p-nitrophenol or testosterone glucuronidation in liver microsomal preparations. Single or repeated doses of these benzodiazepines did not change cytochrome P-450, RNA or protein contents of hepatic microsomes. It is suggested that morphine glucuronyltransferase contains an active site for binding of the N-methyl group present in the substrate. Such a binding site would be absent or in effective in p-nitrophenol and testosterone glucuronyltransferases. The reported inhibition of morphine metabolism by diazepam may account for an enhancement of morphine pharmacological effects.

Immuno-overlay: a method for identification of hepatoma cell colonies that secrete albumin

A screening technique was developed for the identification of clones of hepatoma cells that secrete albumin. The technique employs the overlay of a 1% agarose solution containing antiserum to albumin onto clones of hepatoma cells. A distinct immunoprecipitation complex is formed in the immuno-overlay that corresponds directly to the position of each secreting clone. Clones deficient in albumin secretion do not form an immunoprecipitate. Thus comparison of the immuno-overlay and the cell colonies results in identification of variant clones as well as those capable of secretion. Biochemical characterization of the region of agarose overlay from secreting and nonsecreting clones demonstrates the specificity of the method and its potential for selection of colonies that are secreting other hepatic or cellular proteins.

Time-varying effects in mice and rats of several synthetic ACTH preparations

Circadian stage-dependent effects characterize synthetic ACTH 1-17 preparation (HOE 433 = Synchrodyn 1-17), tested in mice and rats, with reference notably to corticosterone and aldosterone production in vitro and to the behavior of rhythms in these two corticoids as an aspect of the adrenal cortical pacemaker of the circadian system. The possibility to advance or delay the rhythm in serum corticosterone by ACTH 1-17 also is demonstrated, as is a differential behavior of the circadian rhythm in serum aldosterone. Differences in timing of circadian corticosterone and aldosterone responses also are described and await further scrutiny for ultradian and infradian (notably circannual) modulation.

Structural requirements in the reaction of morphine uridine diphosphate glucuronyltransferase with opioid substances

The influence of the 3-hydroxyl and N-alkyl groups in the reactivity of narcotic compounds with morphine UDP-glucuronyltransferase was studied. Opioids possessing both, one or none of these groups were tested for inhibition of morphine glucuronidation in rabbit liver microsomal preparations. Compounds with only a 3-hydroxyl group (normorphine) or an N-methyl group (codeine, ethylmorphine) were less potent competitive inhibitors than those containing both groups (dextrorphan). Norcodeine, with neither of these groups, had no inhibitory effect. The synthetic narcotics (+)- and (-)-methadone, (-)-alpha-acetylmethadol and meperidine, with only an N-alkyl group, were effective competitive inhibitors. No stereoselectivity of the morphine glucuronyltransferase for opioid isomers was observed, and [methionine]enkephalin does not react with morphine glucuronyltransferase. Differences of pKa values and water/lipid solubility of narcotics could not explain the effects. Results indicate that the N-alkyl group plays a critical role in the interaction of narcotics with the morphine UDP-glucuronyltransferase.