287 research outputs found
Domoic Acid
No full texteditors, R.H. Waring, G.B. Steventon, S.C. Mitchell.; Includes bibliographical references and index.; Chapter 4. written by R. Andrew R. Tasker - Domoic acid - UPEI professor, Dept. of Biomedical Sciences.Source type: Print(0
Life Sciences 34 17 1659 1667 ENGLAND
No full textDibutanoylmorphine (DBM), a synthetic diester of morphine, was compared with morphine (M) and diacetylmorphine (DAM) for analgesic efficacy, potency and duration of action following I.V. administration in rats. Analgesia was assessed in groups of eight animals using both tail-flick and hot-plate testing methods following random administration of five different doses of each drug. DBM was found to be substantially more potent than M, but less potent than DAM in both tail-Flick and hot-plate tests of nociception. Similarly, assessment of duration of action at the ED50 for each drug revealed that DBM has a duration of analgesia which is intermediate between the durations of M and DAM. Thus, in rats in vivo, DBM is an effective analgesic and has a reasonable duration of action release to other opioids
Neurotoxicology 19 4-5 593 597 UNITED STATES
No full textWe have examined the behavioural neurotoxicity of domoic acid (DOM) and kainic acid (KA) in mice following administration of ligands active at the N-methyl-d-aspartate (NMDA) receptor. Groups of female CD-1 mice (n=4) were injected i.p. with saline or one of three doses of either DOM or KA. Doses of DOM and KA were selected from the steep portion of the respective dose response curves and were equitoxic when compared between the two ligands. Toxicity was recorded as both total cumulative toxicity over 60 min according to a previously validated 7 point rating scale, and as the latency to the onset of tremors and/or convulsions. Five minutes prior to administration of either agonist mice were injected with either saline, NMDA (40 mg/kg) or a combination of NMDA and 15 mg/kg CPP (3-[2-carboxypiperazine-4-yl]propyl-1-phosphonic acid). Neither NMDA nor CPP at these doses produced significant changes from baseline responding when injected prior to saline. Injection of NMDA prior to DOM, however, resulted in significantly increased cumulative toxicity and significantly reduced latencies to seizures at the two highest doses of DOM (3.75 and 5.0 mg/kg). NMDA-induced potentiation of DOM toxicity was completely antagonized by co-administration of CPP. In contrast, injection of NMDA prior to KA did not result in significant changes in KA toxicity at any of the doses tested using either index of behavioural toxicity. These results confirm previous reports of synergism between DOM and ligands acting at the NMDA receptor in isolated neurons, and provide further evidence of pharmacological dissociation of the actions of DOM and KA in vivo
Cyclopentyl-adenosine decreases caspase-3 activity and LDH release following simulated ischemia in cerebellar granule neurons
No full textActivation of adenosine A1 receptors in vivo or in vitro, prior to simulated ischemic insults have been demonstrated to be neuroprotective. Preconditioning with A1 receptor agonists, both in vivo and in vitro, has been shown to induce neuroprotective effects against necrosis even when administered 24–72 hours before ischemic insult. This thesis examined the neuroprotective effects of the selective A1 receptor agonist, N6-cyclopentyl-adenosine (CPA), against both apoptotic and necrotic cell death following simulated ischemia in cultured rat cerebellar granule neurons. Using antibodies directed towards neuronal nuclear protein and glial fibrillary acid protein, the purity of cerebellar granule cell cultures was found to be 98.6 ± 0.4%. This indicates that the results from these experiments were likely mediated by effects of the drugs and simulated ischemia on neurons and not astrocytes. To determine if the neuroprotection induced by CPA treatment was mediated by activation of A1 receptors, a concentration response curve for DPCPX was generated in the presence and absence of 1μM CPA. (Abstract shortened by UMI.).Source: Masters Abstracts International, Volume: 42-02, page: 0538.Advisers: Marva I. Sweeney-Nixon; Andrew Tasker
- …
