1.
Ploj, Karolina, et al.
(författare)
Basal levels and alcohol-induced changes in nociceptin/orphanin FQ, dynorphin, and enkephalin levels in C57BL/6J mice
2000
Ingår i: Brain Research Bulletin. - 0361-9230 .- 1873-2747. ; 53:2, s. 219-226
Tidskriftsartikel (refereegranskat) abstract
In order to investigate the involvement of the opioid and nociceptin/orphanin FQ (N/OFQ) system in alcohol drinking behaviour, N/OFQ and the opioid peptides dynorphin B (DYNB) and Met-enkephalin-Arg(6) Phe(7) (MEAP) were examined in the alcohol-preferring C57BL/6J mice. Basal peptide levels were compared in the brain and the pituitary gland with basal levels in the alcohol-avoiding DBA/2J mice. Furthermore, the effects of chronic alcohol self-administration on peptides were studied in the C57BL/6J mice. Compared to the DBA/2J mice, C57BL/6J mice had low immunoreactive (ir) levels of DYNB and MEAP in the nucleus accumbens, the hippocampus, and the substantia nigra, low ir-DYNB levels in the striatum and low ir-MEAP levels in the frontal cortex. Higher ir-DYNB levels in the pituitary gland and in the periaqueductal gray (PAG) and higher ir-N/OFQ levels in the frontal cortex and in the hippocampus were detected in C57BL/6J mice compared to the DBA/2J mice. After 4 weeks of voluntary alcohol consumption, only minor changes in steady-state peptide levels were identified. However, 5 days after the alcohol-drinking period, lower levels of all peptides were detected in the ventral tegmental area and ir-DYNB levels were also lower in the amygdala and in the substantia nigra. Twenty-one days after cessation of alcohol self-administration, the opioid peptides in alcohol-consuming C57BL/6J mice were lower in the PAG, the N/OFQ was lower in the frontal cortex and DYNB was higher in the amygdala and substantia nigra as compared to control C57BL/6J mice. This study demonstrates strain differences between C57BL/6J mice and DBA/2J mice that could contribute to divergent drug-taking behaviour, and it also demonstrates time- and structure-specific changes in neuropeptide levels after alcohol self-administration in the C57BL/6J mice.
2.
Graffner-Nordberg, Malin, et al.
(författare)
Computational predictions of binding affinities to dihydrofolate reductase: synthesis and biological evaluation of methotrexate analogues
2000
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 1520-4804 .- 0022-2623. ; 43:21, s. 3852-3861
Tidskriftsartikel (refereegranskat) abstract
The relative binding affinities to human dihydrofolate reductase of four new potential antifolates, containing ester linkages between the two aromatic systems, were estimated by free energy perturbation simulations. The ester analogue, predicted to exhibit the highest binding affinity to human dihydrofolate reductase, and a reference ester (more structurally related to methotrexate) were synthesized. As deduced from the measured IC(50) values, the calculated ranking of the ligands was correct although a greater difference in affinity was indicated by the experimental measurements. Among the new antifolates the most potent inhibitor exhibited a similar pharmacokinetic profile to methotrexate but lacked activity in a complex antiarthritic model in rat in vivo.
3.
Annas, Anita, et al.
(författare)
Differential response of cultured human umbilical vein and artery endothelial cells to Ah receptor agonist treatment : CYP-dependent activation of food and environmental mutagens
2000
Ingår i: Toxicology and Applied Pharmacology. - : Elsevier BV. - 0041-008X .- 1096-0333. ; 169:1, s. 94-101
Tidskriftsartikel (refereegranskat) abstract
In the present study, 7-ethoxyresorufin O-deethylase (EROD), 7,12-dimethylbenz[a]anthracene (DMBA)-hydroxylase, and covalent binding of H-3-labeled 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (H-3-Trp-P-1) and H-3-DMBA were examined in human umbilical vein endothelial cells (HUVEC) and human umbilical artery endothelial cells (HUAEC) exposed to the aryl hydrocarbon (Ah) receptor agonist beta -naphthoflavone (BNF) or vehicle only. The results revealed a marked induction of enzymatic activity in BNF-treated HUVEC compared with vehicle-treated cells, whereas no similar response was observed in BNF-treated HUAEC. EROD, DMBA hydroxylase, and covalent binding of H-3-Trp-P-1 and H-3-DMBA in BNF-treated HUVEC were reduced in the presence of the CYP1A inhibitor ellipticine. Addition of other CYP1A inhibitors ru-naphthoflavone, miconazole, 1-ethynylpyrene, 1-(1-propynyl)pyrene, or the CYP1A substrate ethoyresorufin to the incubation buffer of BNF-treated HUVEC reduced covalent binding of H-3-Trp-P-1 by 93-98%. Western blot analysis confirmed an induction of CYP1A1 in BNF-treated HUVEC, but not in BNF-treated HUAEC. CYP1A1 was, however, detected in both vehicle- and BNF-treated HUAEC. The results showed that BNF exposure induced CYP1A1 and metabolic activation of xenobiotics in HUVEC, whereas the catalytic activity remained low in BNF-treated HUAEC. Our results suggest that endothelial lining of human veins may be a target for adverse effects of xenobiotics activated into reactive metabolites by Ah receptor-regulated enzymes. Several studies have detected CYP1A1 in endothelial linings, whereas expression of CYP1A2 and CYP1B1 seems to be negligible at this site. This suggests that the metabolic activation and covalent binding of H-3-Trp-P-1 and H-3-DMBA in HUVEC are most likely mediated by CYP1A1.
4.
Annas, Anita
(författare)
Metabolism-dependent activation of food and environmental mutagens in endothelial cells
2000
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The endothelial cells of blood vessels have been proposed as a target for toxic effects ofxenobiotics in the cardiovascular system. In the present studies, induction of cytochromeP450 1A (CYP1A) enzymes and metabolic activation of food and environmentalmutagens were examined in endothelial cells of rodents, birds, and humans. Theheterocyclic amine 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and thepolycyclic aromatic hydrocarbons 7,12-dimethylbenz[a]anthracene (DMBA) andbenzo[a]pyrene were used as models for food and environmental mutagens.The results showed that Trp-P-1 was activated into tissue-binding metabolites in endothelial cells, preferentially of capillaries and veins, in rodents pretreated with the aryl hydrocarbon (Ah) receptor agonist β-naphthoflavone (BNF), whereas similar activationdid not occur in vehicle-treated animals. Similarly, exposure to BNF increased the tissue-binding of Trp-P-1 and DMBA in cultured human umbilical vein endothelial cells (HUVEC), as compared with vehicle-treated cells. In contrast, exposure to BNF did not increase the binding of the mutagens in human umbilical artery endothelial cells (HUAEC). The formation of reactive metabolites of Trp-P-1 and DMBA correlated with induction of CYP1A1 protein and/or CYP1A-dependent catalytic activities, such as 7-ethoxyresorufin O-deethylase (EROD) and DMBA hydroxylase, in endothelial cells of rodents and cultured HUVEC. Moreover, exposure to BNF increased the activation ofbenzo[a]pyrene into genotoxic metabolites in HUVEC as compared with vehicle-treated cells.In chicken and eider duck embryos, BNF induced EROD and activation of Trp-P-1 to tissue binding metabolites in the endothelial linings, preferentially of capillaries and veins, in heart and chorioallantoic membrane (CAM). In vehicle-treated embryos, these activities were low.Overall, the present studies show that CYP1A-dependent activation of xenobiotics into tissue binding or genotoxic metabolites can be induced in blood vessel endothelia in various species following exposure to Ah receptor agonists. The results also show that there is a differential response to Ah receptor agonists within the vascular tree; CYP1A and enzymatic activities are preferentially induced in endothelial cells of veins and capillaries, and to lesser extent in arteries. The results suggest that certain endothelial cellsmay be targets for CYP1A-dependent activation of xenobiotics in individuals exposed to Ah receptor agonists.
5.
Bardage, Carola
(författare)
Cardiovascular disease and hypertension : Population-based studies on self-rated health and health-related quality of life in Sweden
2000
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The aim with this thesis was to study cardiovascular disease and hypertension, use of drugs and health from an epidemiological perspective. Various methods - self-rated health (SRH), health related quality of life (HRQL) - the 36-item short form questionnaire (SF-36) - and health utility measurements - the rating scale (RS) and the time-trade off (TTO) methods - were employed.Data from the Swedish Adoption/Twin Study of Aging (SATSA) in 1984, 1987, 1990, and 1993 as well as a general population survey conducted in Uppsala County in 1995 were used.Persons who have cardiovascular disease, both with and without drug treatment, were found to have a lower SRH as compared to others in the population. Longitudinal analyses showed that SRH was relatively stable over time among persons with cardiovascular disease. Both having a low SRH and having cardiovascular disease were associated with a higher mortality rate.Hypertensives were found to have a lower HRQL than do others in the general population as measured by the SF-36. The lowest scoring was found in the general health perception scale (GH), whereas role emotional (RE) and mental health (MH) were the scales least affected by hypertension.Nearly 20 percent of the antihypertensive drug users reported side effects.The pattern of side effects was similar to that reported in clinical trials. Both hypertension itself and the drug treatment were found to have an impact on the patient's health-state utility as measured by the RS. Comparative analyses showed that health utilities and psychometric quality-of-life instruments were only moderately correlated among hypertensives. The results also showed that inequalities in HRQL were present with respect to several sociodemographic factors. In summary, this thesis revealed that persons with cardiovascular disease and/or with hypertension experience poorer health than others in the population. The poor health may be caused both by the disease and/or the drug treatment. The results in this thesis also suggested that special attention and care should be directed to persons with cardiovascular disease and/or hypertension reporting ill health. This especially is important given that low HRQL can be a riskfactor for subsequent cardiovascular events or complications which in turn might result in higher mortality rate.
6.
Bertozzi, Fabio, et al.
(författare)
Temporary in situ aluminum and zinc tethering in Diels-Alder reactions
2000
Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 2:9, s. 1283-1286
Tidskriftsartikel (refereegranskat) abstract
(formula presented) Temporary tethering using aluminum or zinc in Diels-Alder reactions made possible the use of otherwise "noncompatible" combinations of dienes and dienophiles, resulting in the one-step formation of substituted cyclohexene 1,2-bis-methanols. Excellent regioselectivity and also significant stereoselectivity were obtained.
7.
Bouw, Marcel René
(författare)
Microdialysis as a tool in pharmacokinetic-pharmacodynamic studies investigating the brain distribution and effect delay of morphine and morphine-6-glucuronide
2000
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The microdialysis technique was developed as a tool for studying the pharmacokinetic and pharmacodynamicrelationships of morphine and morphine-6-glucronide (M6G). Concentrations of unbound drug in blood andbrain were monitored in order to elucidate the origin of the observed delay in antinociceptive effect in rats.The antinociceptive effect was measured as the response to electrical stimulation of the tail and respiratoryeffects were monitored by measuring the blood gas status. The data analysis was performed in NONMEM andPCNONLIN. It was shown that in vitro testing is an essential step in the selection of a candidate drug for in vivomicrodialysis. A comparative study of in vivo calibration methods showed no significant difference betweenthe unbound concentration-time profiles obtained with retrodialysis by drug or by calibrator (nalorphine).The delay in antinociceptive effect of morphine in relation to the blood concentration was estimated to havean equilibration half-life of 32 min, which was considerably shorter than the equilibration half-life of 103 minfor M6G. Remaining effect delays of 5 or 53 mitt, respectively, were observed when the effect was related tothe brain extracellular fluid (ECF) concentrations of morphine and M6G. Unexpectedly, the brain ECF:bloodratio for unbound morphine (0.25 ± 0.13) was comparable with the value for M6G (0,22 ± O.O9), indicating theinvolvement of active mechanisms of transport across the blood-brain barrier (BBB) for both compounds.Significantly longer half-lives for morphine and M6G were observed in brain (43 ± 9 and 58 ± 17 min,respectively) than in blood (31 ± 8 and 23 ± 5 min, respectively), Thus, redistribution in the brain is the ratelimiting step for the elimination of both morphine and M6G out of the brain.Clinical microdialysis of morphine showed a similar pattern to that observed in the animal studies, with asignificantly longer half-life in uninjured (73 min) or injured (77 min) brain tissue, than in blood (28 min) andadipose tissue (27 min).
8.
Bylund, Johan
(författare)
Cytochrome P450 enzymes in oxygenation of prostaglandin endoperoxides and arachidonic acid : Cloning, expression and catalytic properties of CYP4F8 and CYP4F21
2000
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Cytochrome P450 (P450 or CYP) is an enzyme system involved in the oxygenation of a wide range of endogenous compounds as well as foreign chemicals and drugs. This thesis describes investigations of P450-catalyzed oxygenation of prostaglandins, linoleic and arachidoniacids.The formation of bisallylic hydroxy metabolites of linoleic and arachidonic acids was studied with human recombinant P450s and with human liver microsomes. Several P450 enzymes catalyzed the formation of bisallylic hydroxy metabolites. Inhibition studies and stereochemic analysis of metabolites suggest that the enzyme CYP1A2 may contribute to the biosynthesis of bisallylic hydroxy fatty acid metabolites in adult human liver microsomes.19R-Hydroxy-PGE and 20-hydroxy-PGE are major components of human and ovine semen, respectively. They are formed in the seminal vesicles, but the mechanism of their biosynthesis is unknown. Reverse transcription-polymerase chain reaction using degenerate primers for mammalian CYP4 family genes, revealed expression of two nov P450 genes in human and ovine seminal vesicles. The full coding regions of the genes were cloned and the enzymes were expressed in a yeast system. The human enzyme was designated CYP4F8 and the ovine enzyme was designated CYP4F21. Comparison of their deduced protein sequenceshowed that they had 74 % amino acid identity. Recombinant CYP4F8 oxygenated two prostaglandin endoperoxides (PGH1 and PGH2) and three stable PGH2 analogues int19-hydroxy metabolites. Oxygenation of these substrates was mirrored when incubated with microsomes isolated from human seminal vesicles. These results suggest that CYP4F8 is present in human seminal vesicles and that 19R-hydroxy-PGE is formed by CYP4F8-catalyze 19R-hydroxylation of PGH1 and PGH2, followed by PGE synthase-catalyzed isomerization. Studies of catalytic properties of recombinant CYP4F21 suggest that 20-hydroxy-PGE may be formed by similar mechanisms in ovine seminal vesicles. CYP4F8 is the first enzyme shown to hydroxylate prostaglandin endoperoxides.
9.
Claeson, Ubonwan Pongprayoon, et al.
(författare)
Adhatoda vasica : a critical review of ethnopharmacological and toxicological data
2000
Ingår i: Journal of Ethnopharmacology. - 0378-8741 .- 1872-7573. ; 72:1-2, s. 1-20
Forskningsöversikt (refereegranskat) abstract
Adhatoda vasica (L.) Nees is a well-known plant drug in Ayurvedic and Unani medicine. It has been used for the treatment of various diseases and disorders, particularly for the respiratory tract ailments. During the last 20 years, several scientific reports on oxytocic and abortifacient effects of vasicine and alkaloid derived from the plant have appeared. This leads to questions concerning the safety of A. vasica as a herbal medicine. In this article, the major data on traditional uses as well as ethnopharmacological and toxicological studies, both published and unpublished, are reviewed and commented upon. The data have been evaluated from the point of view of correctness, reliability, relevance and importance for the overall evaluation of the safety of A. vasica.
10.
Dahlin, Maria
(författare)
Nasal administration of compounds active in the central nervous system : Exploring the olfactory system
2000
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The nasal administration of drugs offers advantages over administration by intravenous injection. Drugs can be rapidly absorbed through the nasal mucosa, resulting in a rapid onset of action, and also avoiding degradation in the gastrointestinal tract and first-pass metabolism in the liver. The olfactory receptor cells, which are in direct contact with both the environment and the central nervous system (CNS), are potential routes for drugs into the CNS. The olfactory pathway thus circumvents the blood brain barrier (BBB) which prevents many systemically administered drugs from entering the brain.The studies used compounds active in the CNS and the experiments were performed in rodents. The nasal bioavailability of (S)-UH-301, NXX-066 and [3H]-dopamine was investigated in a rat model; uptake into the cerebrospinal fluid (CSF) was compared after nasal and intravenous administration. The concentrations of S-UH-301 and NXX-066 in plasma and CSF were measured with high performance liquid chromatography. The possible transfer of dopamine and neurotensin along the olfactory pathway after nasal administration to mice was studied using brain tissue sampling and autoradiography. The radioactivity content in blood, CSF and dissected brain tissue samples after administration of [3H]-dopamine and [3H]-neurotensin was assessed using liquid scintillation, and thin layer chromatography (TLC) was used to investigate the metabolic fate of [3H]-dopamine.The results of this thesis suggest that nasal administration of CNS-active compounds with low oral bioavailability is an interesting and workable alternative to intravenous injection. The small lipophilic compounds (S)-UH-301 and NXX-066 were rapidly and completely absorbed after nasal administration, although hard evidence of direct transfer from the nose remains elusive. Radioactivity measurements in the olfactory bulb following nasal administration of[3H]-dopamine and [3H]-neurotensin indicate that transfer occurred. The TLC results showed the presence of unchanged dopamine in the olfactory bulb but it is less clear from initial results with neurotensin, which radioactive products of this molecule reached the olfactory bulb, and further studies are required.
