Effect of δ-9-tetrahydrocannabinol and theophylline on hepatic microsomal drug metabolizing enzymes
TL;DR: Analysis of Lineweaver-Burk plots showed that Th-induced stimulation of hepatic microsomal drug metabolizing enzymes occurs due to an increase in substrate affinity and of V max, while δ-9-tetrahydrocannabinol-induced inhibition of N -demethylase and O -dem methylase is probably due to competition of the drug with the substrates for a common intermediate in theMicrosomal electron transport chain.
About: This article is published in Biochemical Pharmacology.The article was published on 1992-11-17. It has received 2 citations till now. The article focuses on the topics: Demethylase & Aniline Hydroxylase.
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TL;DR: Based on a higher frequency of case reports for upper airway cancer compared to bronchogenic carcinoma, marijuana smoking may have a more deleterious effect on the upper respiratory tract, however, this hypothesis remains speculative at best, pending confirmation by longitudinal studies.
Abstract: Daily marijuana smoking has been clearly shown to have adverse effects on pulmonary function and produce respiratory symptomatology (cough, wheeze, and sputum production) similar to that of tobacco smokers. Based on the tobacco experience, decrements in pulmonary function may be predictive of the future development of chronic obstructive pulmonary disease (COPD). However, in the absence of alpha-1-antitrypsin deficiency, the habitual marijuana-only smoker would likely have to smoke 4-5 joints per day for a span of at least 30 yr in order to develop overt manifestations of COPD. The mutagenic/carcinogenic properties of marijuana smoke are also well-established. The potential for induction of laryngeal, oropharyngeal, and possibly bronchogenic carcinoma from marijuana has been documented by several case reports and observational series. Despite this, a relative risk ratio for the development of these tumors has not yet been quantified. Based on a higher frequency of case reports for upper airway cancer compared to bronchogenic carcinoma, marijuana smoking may have a more deleterious effect on the upper respiratory tract. However, this hypothesis remains speculative at best, pending confirmation by longitudinal studies.
49 citations
TL;DR: Abrogation of the THC-induced inhibition of Th binding to control membranes after solubilization and restoration of the inhibitory effect of THC on Th binding in reconstituted membranes suggest the involvement of membrane lipid in the THC theophylline binding to neuronal and non-neuronal membranes.
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TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
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TL;DR: A chronology of key events leading up to and including the birth of Bonnichsen, R. K. & Bonner, J. (1952).
Abstract: Bonnichsen, R. K. (1947). Arch. Biochem. 12, 83. Dalgliesh, C. E. (1951). Quart. Rev. chem. Soc., Lond., 5,227. Daigliesh, C. E. (1952). Biochem. J. 52, 3. Eckert, H. W. (1943). J. biol. Chem. 148, 205. Elliott, K. A. C. (1932a). Biochem. J. 26, 10. Elliott, K. A. C. (1932b). Biochem. J. 26, 1281. Galston, A. W. (1949). Plant Phy8iol. 24, 577. Gordon, S. A. & Nieva, F. S. (1949). Arch. Biochem. 20,356. Gustafson, F. G. (1949). Science, 110, 279. Happold, F. C. (1950). Advanc. Enzymol. 10, 51. Henderson, J. M. & Bonner, J. (1952). Amer. J. Bot. 39, 444. Horn, M. J. & Jones, D. B. (1945). J. biol. Chem. 157, 153. Keilin, D. & Hartree, E. F. (1951). Biochem. J. 49, 88. Kenten, R. H. & Mann, P. J. G. (1952). Biochem. J. 50,360. Knox, W. E. (1951). Brit. J. exp. Path. 32, 462. Knox, W. E. & Mehler, A. H. (1950). J. biol. Chem. 187,419. Makino, K., Satoh, K., Fujiki, T. & Kawaguchi, K. (1952). Nature, Lond., 170, 977. Morton, R. K. (1950). Nature, Lond., 166, 1092. Nason, A. (1950). Amer. J. Bot. 37, 612. Proctor, B. E. & Bhatia, D. S. (1953). Biochem. J. 53, 1. Reichstein, T. (1932). Helv. chim. acta, 15, 1110. Singer, T. P. & Kearney, E. B. (1950). Arch. Biochem. 29, 190. Sizer, I. W. (1947). Fed. Proc. 6, 202. Stanier, R. Y. & Tsuchida, M. (1949). J. Bact. 58, 45. Tang, Y. W. & Bonner, J. (1947). Arch. Biochem. 13, 11. Teas, H. J. & Anderson, E. G. (1951). Proc. nat. Acad. Sci., Wash., 37, 645. Weil, L., Gordon, N. G. & Buchert, A. R. (1951). Arch. Biochem. 33, 90. Wildman, S. G., Ferm, M. G. & Bonner, J. (1947). Arch. Biochem. 13, 131. Wildman, S. G. & Muir, R. M. (1949). Plant Physiol. 24, 84.
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TL;DR: A simple and definite procedure is proposed for dividing treatments into distinguishable groups, and for determining that the treatments within some of these groups are different, although there is not enough evidence to say "which is which."
Abstract: The practitioner of the analysis of variance often wants to draw as many conclusions as are reasonable about the relation of the true means for individual "treatments," and a statement by the F-test (or the z-test) that they are not all alike leaves him thoroughly unsatisfied. The problem of breaking up the treatment means into distinguishable groups has not been discussed at much length, the solutions given in the various textbooks differ and, what is more important, seem solely based on intuition. After discussing the problem on a basis combining intuition with some hard, cold facts about the distributions of certain test quantities (or "statistics") a simple and definite procedure is proposed for dividing treatments into distinguishable groups, and for determining that the treatments within some of these groups are different, although there is not enough evidence to say "which is which." The procedure is illustrated on examples.
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TL;DR: Two types of spectral changes are described as resulting from substrate interaction with a hepatic microsomal cytochrome; the magnitude of these spectral changes is dependent on protein concentration and substrate concentration as well as the substrate employed.
Abstract: Two types of spectral changes are described as resulting from substrate interaction with a hepatic microsomal cytochrome; the magnitude of these spectral changes is dependent on protein concentration and substrate concentration as well as the substrate employed. In two of the three types of substrates examined, the concentration of substrate necessary to evoke half-maximal enzyme activity was similar to the concentration of the same substrate necessary for half-maximal spectral changes. The addition of NADPH, a corequirement for the microsomal mixed function oxidase, causes a modification of both types of spectral changes, without altering substrate affinity. Three possible hypotheses are advanced, based upon the experimental observations, to explain the two types of spectral changes observed.
1,110 citations