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Die invloed van polisikliese amiene op die kalium- en natriumkanale van ge"isoleerde marmothartselle

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dc.contributor.author Wagenaar B en
dc.date.accessioned 2016-09-22T07:17:28Z
dc.date.available 2016-09-22T07:17:28Z
dc.date.created 1997 en
dc.date.submitted 1997 en
dc.identifier.uri http://hdl.handle.net/20.500.11892/11395
dc.description.abstract A comparative study between two polycyclic amines, NGP 1-01 (NGP) and SFM 1B (1B) has shown that small structures changes in the NGP compound, changes its binding properties, and therefore 1B shows greater specificity for Na-channel antagonism than the NGP compound. The difference in the structure lies firstly in the bigger cage of 1B and a hydroxyl group instead of the internal ether bond of NGP. In both cases the aromatic side chain is the same. The Langendorff-perfusion technique was used for the enzymatic isolation of ventricular myocytes from adult guinea pig hearts. Experimental procedures were done according to the whole cell patch-clamp technique. By means of whole cell studies the mechanism of antagonism of a drug can be studied by measuring channelblockade and modulation of channel kinetics. The influence of 1B on the inactivated state of the sodium channel (Naplus channel) causes a reduction of channel availability which results in the reduction of current magnitude. NGP antagonistic influences take place by means of channelblockade rather than modulation. Differences in the slope of the dose-response curve, is an indication of the binding relation of the ligand and the receptor. A mean slope of 1 for 1B is denotative of a 1 to a reaction between the ligand and the receptor and is an indication of the specific binding propertie4s of 1B. For NGP a mean slope of 0.38 (less than 0.5) was obtained, which indicates that there exists a heterogeneity in a population of binding sites or receptors where binding does not occur with the same affinity. The selectivity of 1B was determined by measuring the influence of 1B on different types of potassium currents (kplus currents). It was found that 1B inhibits the rapid as well as the slow components of the delayed rectifier Kplus current (Ikr and Iks, respectively), but had no effect on the inward rectifying Kplus current (IK1). The relative small structure changes in the cage structure which induce Kplus-, Ca2plus- and Naplus-specificity, create interesting possibilities in regards to the primary and secondary origin of different ion channel types, as well as the development of substance with specific origin of different ion channel types, as well as the development of substance with specific as well as selective properties. Conclusively it can be postulated that 1B's binding specificity for the Naplus-channel is bigger that that of NGP. The delayed rectifier Kplus-current, slow and fast components are also suppressed by 1B. en
dc.language Afrikaans en
dc.subject Medical sciences: Physiology en
dc.subject Blood and circulation en
dc.title Die invloed van polisikliese amiene op die kalium- en natriumkanale van ge"isoleerde marmothartselle en
dc.type Masters degree en
dc.description.degree MSc en


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