Investigations with GMC2021 in experimental models predictive of antimigraine activity and coronary side-effect potential

Abstract Several acutely acting antimigraine drugs, including sumatriptan and other second generation 5-HT1D receptor agonists, have the ability to constrict porcine carotid arteriovenous anastomoses as well as the human isolated coronary artery. These two experimental models seem to serve as indicators, respectively, for the therapeutic and coronary side-effect potential of the compounds. Using these two models, we have now investigated the effects of GMC2021 (3-[2-(dimethylanimo)ethyl]-5-[(trifluoromethyl)sulfonyl]oxy][1 H]indole oxalate, a close analogue of sumatriptan. GMC2021 (30, 100, 300 and 1000 μg · kg−1, i.v.) decreased the total carotid blood flow by exclusively decreasing arteriovenous anastomotic blood flow; capillary blood flow to the skin and ears was moderately increased. The mean ± S.E.M. dose of GMC2021 eliciting a 50% decrease (ED50) in the porcine carotid arteriovenous anastomotic blood flow was found to be 1.1 ± 0.3 μmol · kg−1 and the highest dose (1000 μg · kg−1) produced a 67 ± 4% reduction. The carotid haemodynamic effects of GMC2021 were reduced by the selective 5-HT1D receptor antagonist, GR127935 (N-[methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2′-methyl-4′-(5-methyl-1,2,4-oxadiazol-3-yl)[1,1-biphenyl]-4-carbboxamide hydrochloride), which completely antagonizes porcine carotid haemodynamic responses to sumatriptan (ED50: 0.16 μmol · kg−1, i.v.). Compared to sumatriptan (pD2: 6.12 ± 0.15; Emax: 31.3 ± 12.3% of contractions to 100 mM K+), GMC2021 was less potent in constricting the human isolated coronary artery (pD2: 5.45 ± 0.2; Emax: 21.0 ± 4.8% of contractions to 100 mM K+). The above results suggest that GMC2021 constricts carotid arteriovenous anastomoses partly by a 5-HT1D receptor and partly by another, probably novel, receptor and that GMC2021 should be able to abort migraine headaches in patients, with perhaps a less propensity for coronary side effects

Effects of avitriptan, a new 5 HT(1B/1D) receptor agonist, in experimental models predictive of antimigraine activity and coronary side-effect potential

Abstract Several acutely acting antimigraine drugs, including ergotamine and sumatriptan, have the ability to constrict porcine arteriovenous anastomoses as well as the human isolated coronary artery. These two experimental models seem to serve as indicators, respectively, f

Changing balances in Dutch higher education

Like many other higher education systems in the Western world, Dutch higher education underwent profound changes during the last decade. In this article we will present an overview of these changes, and try to formulate an analytical framework that might be suited to analyze this process. In order to set the stage, we will begin with an overview of the Dutch higher education system, in which the broad structure is described, and some trends are presented. Next, an overview is given of the retrenchment and restructuring operations with which Dutch higher education was confronted during the last decade. Drawing, mainly, on public administration and political theory, we then attempt to formulate a framework for analysis. In this we focus on the Dutch higher education system as a policy network, and address the relationships that exist between the various key actors in the network: between government and higher education, among higher education institutions themselves, and among the different actors within the institutions, especially administrators and academics. In doing so, we hope to demonstrate that at all these levels some identical basic processes operate which to a large extent determine the outcomes of governmental policies aimed at changing the higher education system. Time and again the modern state stumbles over the academic system (Clark 1983: 137