Background and Purpose-Darbepoetin alfa is a novel erythropoiesis-stimulating protein developed for treating anemia.In animal models, exogenous recombinant human erythropoietin has been reported to be beneficial in treating experimental cerebral ischemia. In this study, we determined whether darbepoetin alfa would protect in a rat model of transient focal cerebral ischemia. Methods-Rats received 2-hour middle cerebral artery suture-occlusion. The drug (darbepoetin alfa, 10 g/kg) or vehicle was administered intraperitoneally 2 hours after onset of middle cerebral artery occlusion. Animals were allowed to survive for 3 or 14 days. Behavioral tests were performed sequentially. Infarct volumes and brain swelling were determined. Results-Darbepoetin alfa-treated rats showed improved neuroscores relative to vehicle-treated animals beginning within 1 hour of treatment and persisting throughout the 14-day survival period. Darbepoetin alfa significantly reduced corrected total (cortical ϩ subcortical) infarct volume (56.3Ϯ20.6 and 110.8Ϯ6.8 mm 3 , respectively) and total infarct areas at multiple levels compared with vehicle in the 14-day survival group. Brain swelling was not affected by treatment.
Conclusion-Darbepoetin
Background and Purpose-Acute intracerebral hemorrhage (ICH) is a common and severe form of stroke. To date, medical management of ICH has had scant impact on morbidity and mortality. Because albumin therapy is markedly neuroprotective in preclinical models of ischemic stroke, and because ischemic and hemorrhagic stroke share several common injury mechanisms, we hypothesized that albumin therapy might also benefit ICH. Methods-Acute intracortical hematoma was produced in anesthetized, normothermic rats by the single stereotaxic injection of 50 L of autologous, nonheparinized whole blood over 5 minutes. Separate animal groups were treated either with 25% human albumin, 1.25 g/kg, or with intravenous saline vehicle at 60 minutes after ICH. Neurobehavior was quantified sequentially over the next 2 to 7 days. Damage to the blood-brain barrier was assessed at 2 days after ICH by fluorometric measurement of Evans blue extravasation in dissected brain regions. Results-High-grade neurological deficits were present in all rats at 50 minutes after ICH (score 10.3Ϯ0.2, meanϮSEM [maximal score 12]). Albumin-treated rats showed improved neuroscores relative to saline-treated animals beginning within hours of treatment and persisting throughout the 7-day survival period. At 3 and 7 days, mean total neuroscores of the albumin group were 38% to 43% lower than in saline-treated animals. Perihematomal Evans blue discoloration was readily evident in saline-treated ICH rats but was reduced by albumin treatment.
Stilbazulenyl nitrone (STAZN) is a potent lipophilic secondgeneration azulenyl nitrone antioxidant, which is highly neuroprotective in rodent models of cerebral ischemia and trauma. This study was conducted to establish whether the neuroprotection induced by STAZN persists with chronic survival and to characterize STAZNЈs pharmacokinetics. Physiologically regulated rats received a 2-h middle cerebral artery occlusion by intraluminal suture and were treated with either STAZN [four 0.6 mg/kg doses i.p. administered at 2 (i.e., onset of recirculation), 4, 24, and 48 h; n ϭ 16] or dimethyl sulfoxide vehicle (n ϭ 11). They received sequential neurobehavioral examinations followed by quantitative neuropathology at 30 days. STAZN improved neurological deficits compared with vehicle controls, beginning within Ͻ2 h of the first dose and persisting throughout a 30-day survival. Large cystic necrotic infarcts were common in vehicle-treated rats but infrequent in STAZN-treated rats, and noninfarcted forebrain tissue was increased on average by 15%. In normal rats administered 5 mg/kg STAZN i.v. in Solutol HS 15/ethanol/saline vehicle, STAZN blood levels exhibited a biexponential decline, with an initial half-life of 28 min and a subsequent slow decay with half-life of ϳ7 h. STAZN tissue levels at 2 to 3 h were, on average, 2.5% of blood levels in forebrain, 56% in myocardium, and 41% in kidney. STAZN was concentrated in liver with initial concentrations averaging 5.2-fold above blood levels and a subsequent linear decline of 40% between 24 and 72 h. These results establish that STAZN confers enduring ischemic neuroprotection, has a long circulating half-life, and penetrates well into brain and other organs-characteristics favoring its potential therapeutic utility.
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