The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
Masaki Otagiri - One of the best experts on this subject based on the ideXlab platform.
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Stereoselective protein binding of Alprenolol in the renal diseased state
Chirality, 2002Co-Authors: Hitoshi Imamura, Takafumi Komori, Ahmed Ismail, Ayaka Suenaga, Masaki OtagiriAbstract:The investigation was undertaken to study the stereoselective protein binding of Alprenolol in renal disease patient sera, compared to that in the sera of healthy volunteers. The in vitro stereoselective protein binding of β-blockers was determined in undiluted serum and in isolated α1-acid glycoprotein (AGP) solutions by ultrafiltration. The stereoselctive serum protein binding of Alprenolol, a β-adrenergic blocking agent, in healthy volunteers was significantly altered in renal disease patients. We investigated the effects of AGP concentration and endogenous substances, including uremic toxins, on the stereoselective protein binding of Alprenolol in renal disease patients. A good correlation between the unbound (R)/(S) ratio (FR/FS ratio), an apparent index of stereoselectivity in Alprenolol serum binding and AGP concentration in serum, was found. However, stereoselective protein binding was not influenced by endogenous substances. This result can be explained by the difference in binding affinities of (R) and (S)-isomers of Alprenolol to AGP. We conclude that the stereoselective protein binding of Alprenolol in healthy volunteers and renal disease patients varies as a result of changes in AGP concentration. Accordingly, these findings might be useful in Alprenolol therapy in renal disease patients. Chirality 14:599–603, 2002. © 2002 Wiley-Liss, Inc.
Reidun Ursin - One of the best experts on this subject based on the ideXlab platform.
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The 5-HT1A antagonist (-)-Alprenolol fails to modify sleep or zimeldine-induced sleep-waking effects in rats.
Pharmacology biochemistry and behavior, 1992Co-Authors: Bjørn Bjorvatn, Dag Neckelmann, Reidun UrsinAbstract:Sleep and waking in rats were studied for 8 h following administration of a selective 5-hydroxytryptamine (5-HT) reuptake inhibitor (zimeldine), a putative 5-HT1A antagonist {L(−)-Alprenolol hydrogene tartrate monohydrate [(−)-Alprenolol]} and a combination of (−)-Alprenolol and zimeldine. Consistent with earlier findings, zimeldine gave a biphasic effect on sleep and waking. Waking was increased during the first 3 h, followed by a small decrease. Deep slow-wave sleep (SWS-2) showed the opposite trend. An initial decrease in SWS-2 was followed by an increase after around 3 h. Rapid eye movement sleep was markedly suppressed and latencies to sleep increased after zimeldine. (−)-Alprenolol had no effects on the different sleep and waking stages or latencies to sleep. The 5-HT1A antagonist also failed to modify the effects of zimeldine administration. The behavioral syndrome induced by a selective 5-HT1A agonist [8-hydroxy-2-(di-n-propyl-amino)-tetralin (8-OH-DPAT)] was clearly antagonized by administration of (−)-Alprenolol, indicating that (−)-Alprenolol was an efficient 5-HT1A blocker. The data indicate that the sleep-waking effects of zimeldine cannot easily be explained by stimulation of 5-HT1A receptors.
Goran Pettersson - One of the best experts on this subject based on the ideXlab platform.
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microcalorimetric studies on the complex formation between cellobiohydrolase i cbh i from trichoderma reesei and the r and s enantiomers of the β receptor blocking agent Alprenolol
Thermochimica Acta, 2000Co-Authors: Mikael Hedeland, Hongbin Henriksson, Per Backman, Roland Isaksson, Goran PetterssonAbstract:Abstract The thermodynamic quantities for the complex formation between the enantiomers of the β-blocking drug Alprenolol and cellobiohydrolase I (CBH I), that earlier has been used as a chiral selector for aminoalcohols, revealed positive ΔH0 — values in all cases implying an entropy driven process. Association constants (Ka) for cellulase and the (R)- and (S)-enantiomers of Alprenolol were determined by isothermal titration microcalorimetry and the inhibition constants (Ki) by enzyme inhibition experiments. Both inhibition experiments and microcalorimetry revealed that the affinity between the enantiomers of Alprenolol and CBH I was higher in sodium phosphate buffer than in potassium phosphate buffer. This result was in agreement with previously reported liquid chromatographic separations of enantiomers using a chiral stationary phase based on CBH I immobilized to silica particles. The best fit of the isothermal titration data corresponded to a 1:1 binding isotherm.
Hitoshi Imamura - One of the best experts on this subject based on the ideXlab platform.
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Stereoselective protein binding of Alprenolol in the renal diseased state
Chirality, 2002Co-Authors: Hitoshi Imamura, Takafumi Komori, Ahmed Ismail, Ayaka Suenaga, Masaki OtagiriAbstract:The investigation was undertaken to study the stereoselective protein binding of Alprenolol in renal disease patient sera, compared to that in the sera of healthy volunteers. The in vitro stereoselective protein binding of β-blockers was determined in undiluted serum and in isolated α1-acid glycoprotein (AGP) solutions by ultrafiltration. The stereoselctive serum protein binding of Alprenolol, a β-adrenergic blocking agent, in healthy volunteers was significantly altered in renal disease patients. We investigated the effects of AGP concentration and endogenous substances, including uremic toxins, on the stereoselective protein binding of Alprenolol in renal disease patients. A good correlation between the unbound (R)/(S) ratio (FR/FS ratio), an apparent index of stereoselectivity in Alprenolol serum binding and AGP concentration in serum, was found. However, stereoselective protein binding was not influenced by endogenous substances. This result can be explained by the difference in binding affinities of (R) and (S)-isomers of Alprenolol to AGP. We conclude that the stereoselective protein binding of Alprenolol in healthy volunteers and renal disease patients varies as a result of changes in AGP concentration. Accordingly, these findings might be useful in Alprenolol therapy in renal disease patients. Chirality 14:599–603, 2002. © 2002 Wiley-Liss, Inc.
Lennart Svensson - One of the best experts on this subject based on the ideXlab platform.
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Alprenolol potentiates the disrupting effects of dizocilpine on sensorimotor function in the rat
Psychopharmacology, 1997Co-Authors: Jianhua Zhang, Jörgen A. Engel, David M. Jackson, Christina Johansson, Lennart SvenssonAbstract:The β-adrenoceptor antagonist as well as serotonin 5-HT1 receptor antagonist, (−)Alprenolol, was found to potentiate the disrupting effect of the non-competitive NMDA receptor antagonist, dizocilpine, on prepulse inhibition (PPI) of the acoustic startle response (ASR) in the rat. The facilitating effect of dizocilpine on ASR amplitude was also potentiated by (−)Alprenolol. (−)Alprenolol by itself did not affect either of these measures. These effects did not seem to be related to the unselective β-adrenoceptor antagonist property of (−)Alprenolol, since combined pretreatment with the β1- and β2-adrenoceptor antagonists, metoprolol and ICI 118551, did not alter the effects of dizocilpine on startle behaviour. However, a serotonergic influence was suggested by the fact that a facilitating effect of dizocilpine on ASR amplitude was also obtained by pretreatment with the 5-HT precursor, L-5-HTP, in benserazide-pretreated rats. Furthermore, pretreatment with the 5-HT2 selective receptor antagonist, MDL 100907, significantly reduced the (−)Alprenolol-induced potentiation of the effects of dizocilpine on startle behaviour, while the 5-HT3 selective receptor antagonist, ondansetron, failed to do that. Finally, the (−)Alprenolol-induced potentiation of the effects of dizocilpine was significantly reduced by pretreatment with the atypical antipsychotic, clozapine, and by the potential antipsychotic and selective dopamine D2 receptor antagonist, raclopride. This study suggests that altered 5-HT activity may influence the effects of psychotomimetic drugs such as dizocilpine on sensorimotor function, and this observation may have implications for the pharmacological treatment of schizophrenia in humans.