Regulation ofL-valine absorption by opioids interacting withμ-receptors in rabbit ileum

In intact tissue, [d-Ala²,MePhe⁴, Gly-ol⁵] enkephalin (10^–5 M;-ligand), diminsihed short-circuit current (I_sc) and increased water, Na⁺ and Cl^– net fluxes in vitro under open circuit conditions; it also inhibitedL-valine absorption andL-valine-dependent variations of short-circuit current (I_{sc, val}). Naloxone (10^–6 M) antagonized these effects. In the absence of the muscularis and myenteric plexus this enkephalin or morphine (-ligand) reduced I_sc and I_{sc, val}. These enkephalin effects occurred at different times. Different concentrations of enkephalin were tested for their effects on I_{sc, val}. [d-Ala²,d-Leu⁵] enkephalin (mainly a -ligand) significantly decreased I_sc but not I_{sc, val}. The reduction ofL-valine absorption does not depend on the effects on basal ion transport. Interaction of opioids with-receptors located in the submucosal plexus and/or in the epithelial cell accounts for this reduction. This enkephalin effect seems to be at least partially under the control of the myenteric plexus.     

Thermodynamics of bromate and iodate of potassium in dioxane-water mixtures from conductance measurements

Summary The free energy of transfer ( G _t ⁰ ) of KBrO₃ and KIO₃ from water to 10, 20 and 30% dioxane-water mixtures have been studied from conductometric measurements. The G _t ⁰ values are in the order of BrO ₃ ^– >IO ₃ ^– .     

Hashish VI1: Conversion of (-)-Δ 1(6)-Tetrahydrocannabinol to (-)-Δ 1(7)-Tetrahydrocannabinol. Stability of (-)-Δ 1 and (-)-Δ 1(6)-Tetrahydrocannabinols

Zusammenfassung Die Synthese von (—)-¹⁽⁷⁾-Tetrahydrocannabinol (THC) auf (—)-¹⁽⁶⁾ wird beschrieben. Das Hauptprodukt der oxidativen Zerstörung von (—)-¹-THC ist Cannabinol. Beschleunigte Versuche der Luftoxidation von (—)-¹-THC und (—)-¹⁽⁶⁾-THC haben gezeigt, dass das letztere beständiger ist. Dieser Unterschied kann mit der Reaktivität des C₃-benzylisch-allylischen Wasserstoffes in (—)-¹-THC erklärt werden.     

Thermodynamics of bromate and iodate of sodium in dioxane-water mixtures at different temperatures

Summary The free energy transfer (G _t ⁰ ) enthalpy of transfer (H _t ⁰ ) and entropy of transfer (S _t ⁰ ) of NaBrO₃ and NaIO₃ from water to 10, 20 and 30% dioxane-water mixtures have been studied using conductance measurements. The chemical and electrical parts of these transfers of thermodynamic parameters have been estimated.To whom reprint requests should be addressed.     

416-1416-1416-1416-2416-2416-2

Summary (–)-8-Hydroxymethyl-¹-tetrahydrocannabinol (THC)1, a novel analog of ¹, is shown to be as active as ¹ and twice as active as ¹ in the dog ataxia test.Acknowledgment. This work was supported by NIDA (Grant Nos. DA-00574-01 and DA-00490).     

(−)-Δ8-tetrahydrocannabinol: Two novel in vitro metabolites

Zusammenfassung (–)-⁸-Tetrahydrocannabinol ist einer der Aktivstoffe in Marihuana (Cannabis sativa L.). Inkubation dieser Verbindung mit der überstehenden Zentrifugationsfraktion (9000g) aus männlicher Hundeleber ergab zwei Hauptmetaboliten, welche durch Massenspektrometrie und Kernresonanzspektroskopie identifiziert wurden. Den beiden Verbindungen werden die Strukturen des 1-Hydroxy-⁸-tetrahydrocannabinols und des 3-Hydroxy-⁸-tetrahydrocannabinols zugeordnet.     

Cl−/HCO 3 − exchanger is operative in isolated enterocytes from rat jejunum

Enterocytes isolated from rat jejunum were tested for the existence of a Cl^–/HCO ₃ ^– exchange, previously evidenced in basolateral membrane vesicles but not in brush border. Cells were found to retain functional integrity and transport capabilities long enough to allow Cl^– fluxes to be measured. Both efflux and uptake experiments indicate that a Cl^–/HCO ₃ ^– antiport, inhibited by 4,4-diisothiocyanostilbene-2-2-disulfonic acid (DIDS), is functional under resting conditions.     

Inhibition of catalase by (Arylthio)-acetohydroxamic acids

Zusammenfassung Leberkatalase wird durch (Arylthio)-acetohydroxamsäure gehemmt. I₆₀ Werte: 4.5·10^–3 to 1,0·10^–4 M.p-Bromoderivat (pI₅₀=4.0) zeigt die stärkste Hemmung. Substitution in der Para-Stellung des Benzol Ringes verursacht eine zunehmende Hemmung in der Reihenfolge: CH₃OCH₃ClBr. Es wird vermutet, dass sich der Hemmstoff nicht mit dem aktiven Zentrum des Ferments verbindet.     

The partitioning ofΔ 1-tetrahydrocannabinol into erythrocyte membranes in vivo and its effect on membrane fluidity1into erythrocyte membranes in vivo and its effect on membrane fluidity1

Summary ¹-Tetrahydrocannabinol ( ¹-THC) has been quantified directly in erythrocyte membranes from drug-treated mice using gas chromatography/mass spectrometry. Concentrations of approximately 6 ng ¹-THC/mg membrane protein (10^–5 M) were found when effects of the drug on behavior were prevalent. At these concentrations the drug produced a decrease in membrane order as measured by ESR.This work was supported by grants from the Medical Research Council, the Wellcome Trust and the E. P. Abraham Cephalosporin Trust     

Inhibition of human testicular glucose-6-phosphate dehydrogenase by unsaturated C19-steroids

Zusammenfassung Die Bebrütung einer gereinigten G-6-PDH aus menschlichem Testisgewebe mit 3-substituierten ⁴- oder ⁵-C₁₉-Steroiden zeigte, dass 3-Hydroxy-⁴-oder ⁵-androsten-17-on auch wirksame Inhibitoren der testikulären G-6-PDH darstellen. Zur gleichen Zeit konnten die früher gefundenen Zusammenhänge zwischen chemischer Struktur eines Steroids und seiner biologischen Aktivität im G-6-PDH-Hemmtest uneingeschränkt bestätigt werden.     

The free radical oxidation of the tetrahydrocannabinols

Summary The free radical oxidation of ¹ and ⁶-tetrahydrocannabinol has been examined by spin trapping techniques and intermediates that would lead to cannabinol have been trapped. The 1st step in the oxidation of ¹-THC involves the removal of 3-H, while for ⁶-THC, either 2-H or 5-H. Intermediates were isolated which could be pyrolysed to the diene and cannabinol.     

Open-field behavior and acquisition of discriminative response control in Δ9-THC tolerant rats

Résumé La tolérance de l'effet du 1- ⁹-tétrahydrocannabinol ( ⁹-THC) a été examinée par une méthode nouvelle. Les résultats obtenus permettent une interprétation de tolérance pharmacologique pour ⁹-THC.

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Numbering system according to IUPAC rules. The drug was generously supplied by Dr.T. Petrzilka, University of Zürich.     

Heterogeneity of erythrocyte catalase: Variability of the isoelectric point

Zusammenfassung Mittels isoelektrischer Fokussierung wurde der IEP von nativer Erythrocytenkatalase bestimmt (Mensch pH 6,5; Pferd pH 7,3). Die im Verlauf der Reinigung auftretende Konformationsänderung ist von einer Verschiebung des IEP nach der sauren Seite begleitet (Mensch pH —1,3; Pferd lpH –1,6).     

Simple integrated rate equations for reversible bimolecular reactions

Summary If the complete rate equations for reversible, one-step, bimolecular reactions are written withP _e–P as the concentration variable (whereP _e is the equilibrium, andP is the instantaneous, product concentration), the 3 possible stoichiometries can be reduced to a single straightforward differential equation. This can be solved very economically. For each stoichiometry, weret is time,k ₁ is the forward rate constant,K _e is the equilibrium constant, and P isP–P _o. The termsP _c–P _o andD+P _c–P _o are the physically possible and physically impossible roots of the quadratic equation forP _e–P _o in terms of the initial concentrations andK _c.D is the discriminant in this equation. All 3 quantities can be calculated if the equilibrium constant is known. A plot oft against ln{[1–P/(D+P _c–P _o)]/[1–P/(P _c–P _o)]} should be a straight line for any second order reaction. For each stoichiometry,P _c–P _o approachesA _o, the initial concentration of the first reactant, as the equilibrium constant increases. When a second reactant is present,D+P _e–P _o approachesB _o. The limiting equation is then that of an irreversible bimolecular reaction. For AP+Q,D approaches –K _e as the equilibrium constant becomes large, and the value of the second logarithmic term in the integrated equation approaches zero. The limiting equation is that of an irreversible, unimolecular reaction.Acknowledgments. I thank Dr. Athel Cornish-Bowden for many helpful discussions. This work was partially supported by a grant from Utah State University.     

Experimental data on the energetic flux during glycolytic oscillations in yeast extracts

Calorimetric experiments were performed on yeast extracts in which glycolytic oscillations were occurring. High metabolic fluxes coincided with low amplitudes and with high frequencies in a temperature range from 283 to 303 K, yielding an activation energy ofE _a=76.8 kJ mol^–1 and a mean Q₁₀ value of 2.5±0.4. The calorimetrically determined reaction enthalpy _fH^0, of the glycolytic catabolism of glucose revealed two distinct groups of extract preparations, with no intermediate values. The values were –107.5±28.7 kJ mol^–1 and –30.8±5.7 kJmol^–1, respectively, while –100.0 kJ mol^–1 was predicted from theoretical calculations. Kreuzberg and Betz⁶ predicted rate limiting effects of GAPDH in oscillating extracts. However, when possible effects of GAPDH on frequency, number of oscillations or total heat production were examined, no influence of increasing or reducing the initial GAPDH concentration could be found. The results are discussed with reference to existing models of glycolytic oscillations.     

Isomeric homoallylic cations formed from 19-substituted steroids

Zusammenfassung Die Existenz von zwei verschiedenen isomeren Homoallylkationen in der Umlagerung von Steroid- ⁵-19-Methansulfonsäure-Estern zu 5, 19-cyclo-6-hydroxylierten Steroiden und deren Umlagerung zu ⁵(¹⁰)-B-homo-7-hydroxylierten Steroiden wurde bewiesen, und eine neue Art der Homoallylumlagerung eines ⁵(¹⁰)-B-homo-7-hydroxylierten Steroids zum 5, 6-Methano-9-en und zum 5, 6-Methano-10-ol wurde beobachtet.

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This material was presented at theSymposium on Steroids Made Through Intramolecular Functionalization on the C ₁₈-and C ₁₉-Methyl Groups, at the 149th meeting of the American Chemical Society in Detroit (Michigan), on April 7, 1965.     

The isolation and structure of trichosiderin B

Riassunto Un nuovo pigmento feomelanico, denominato tricosiderina B, è stato isolato dalle piume di pollo di razza New Hampshire. Sulla base delle proprietà chimiche e spettrali a tale pigmento, C₂₃H₂₀N₄O₉S₂, è stata assegnata la struttura ^2,2-bibenzotiazinica IV.

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This work was supported by a grant from Laboratorio per la Chimica e Fisica di Molecole di Interesse Biologico del C.N.R., Napoli.     

Bildung von 17α-Hydroxy-Δ5-pregnenolon und 3β-Hydroxy-17-keto-Δ5-androsten (DHA) in Nebennieren- und Testes-Gewebe

Summary The transformation of ⁵-pregnenolone into 17-hydroxy-⁵-pregnenolone, and of the latter into DHA, is shown to occur in homogenates and fractions thereof, both of bovine adrenal and testicular tissue. The relative significance of these reactions for the biogenesis of androgens in normal and neoplastic tissue is discussed.

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173. Mitteilung über Steroide; 172. Mitteilung:P. Wieland, K. Heusler undA. Wettstein, Helv. chim. Acta43, 2066 (1960).     

Effect of 723-1723-1723-1on ethanol withdrawal in mice

Summary ⁹ (10 mg/kg, i.p.) administered to mice immediately after withdrawal from a 3-day exposure to ethanol vapor was found to intensify withdrawal reactions. No effect was seen when ⁹ was administered chronically during the exposure to ethanol.