Duchenne muscular dystrophy is a relatively common disease that affects skeletal muscle, leading to progressive paralysis and death. There is currently no resolutive therapy. We have developed a treatment in which we combined the effects of nitric oxide with nonsteroidal antiinflammatory activity by using HCT 1026, a nitric oxide-releasing derivative of flurbiprofen. Here, we report the results of long-term (1-year) oral treatment with HCT 1026 of two murine models for limb girdle and Duchenne muscular dystrophies (␣-sarcoglycan-null and mdx mice). In both models, HCT 1026 significantly ameliorated the morphological, biochemical, and functional phenotype in the absence of secondary effects, efficiently slowing down disease progression. HCT 1026 acted by reducing inflammation, preventing muscle damage, and preserving the number and function of satellite cells. HCT 1026 was significantly more effective than the corticosteroid prednisolone, which was analyzed in parallel. As an additional beneficial effect, HCT 1026 enhanced the therapeutic efficacy of arterially delivered donor stem cells, by increasing 4-fold their ability to migrate and reconstitute muscle fibers. The therapeutic strategy we propose is not selective for a subset of mutations; it provides ground for immediate clinical experimentation with HCT 1026 alone, which is approved for use in humans; and it sets the stage for combined therapies with donor or autologous, genetically corrected stem cells.HCT 1026 ͉ satellite cells ͉ skeletal muscle ͉ ␣-sarcoglycan-null mice ͉ mdx mice

Background-Adenosine is a potent coronary vasodilator and causes an increase of coronary blood flow by activation of A 2A -adenosine receptors (A 2A -AdoRs). The purpose of this study was to test the hypothesis that the high potency of adenosine and adenosine analogues to cause coronary vasodilation is explained by the presence of a large A 2A -AdoR reserve ("spare receptors"). Methods and Results-A novel, irreversible antagonist of A 2A -AdoRs was used to inactivate receptors and reduce the response to agonist. Agonist-induced increases of coronary conductance before and after exposure of hearts to the irreversible antagonist were compared. Three agonists were studied: 2-p-(2-carboxyethyl)-phenethylamino-5Ј-N-ethylcarboxamidoadenosine (CGS21680), adenosine, and 2-chloro-N 6 -cyclopentyladenosine (CCPA). Data were analyzed to determine agonist K A (equilibrium dissociation constant) and EC 50 values. Values of K A for activation of A 2A -AdoRs by CGS21680, adenosine, and CCPA were 105, 1800, and 2630 nmol/L, respectively. In contrast, values of EC 50 for CGS21680, adenosine, and CCPA to increase coronary conductance were 1.5, 85, and 243 nmol/L, respectively. By use of the law of mass action, it was calculated that half-maximal responses to CGS21680, adenosine, and CCPA occurred when only 1.3%, 5%, and 9%, respectively, of A 2A -AdoRs were occupied by agonist. Conclusions-Receptor

Blockade of adenosine receptors can reduce cerebral infarct size in the model of global ischaemia. Using the potent and selective A2A adenosine receptor antagonist, SCH 58261, we assessed whether A2A receptors are involved in the neuronal damage following focal cerebral ischaemia as induced by occluding the left middle cerebral artery. SCH 58261 (0.01 mg/kg either i.p. or i.v.) administered to normotensive rats 10 min after ischaemia markedly reduced cortical infarct volume as measured 24 h later (30% vs controls, p < 0.05). Similar effects were observed when SCH 58261 (0.01 mg/kg, i.p.) was administered to hypertensive rats (28% infarct volume reduction vs controls, p < 0.05). Neuroprotective properties of SCH 58261 administered after ischaemia indicate that blockade of A2A adenosine receptors is a potentially useful biological target for the reduction of brain injury.

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1 The aim of this work was to evaluate the role of leukotrienes in brain damage in vivo in a model of focal cerebral ischaemia in the rat, obtained by permanent occlusion of middle cerebral artery. 2 A signi®cant (P50.01) elevation of LTC 4 , LTD 4 and LTE 4 (cysteinyl-leukotrienes) levels occurred 4 h after ischaemia induction in the ipsilateral cortices of ischaemic compared to shamoperated animals (3998+475 and 897+170 fmol g 71 tissue, respectively, P50.01). 3 The NMDA receptor antagonist MK-801 and the adenosine A 2A receptor antagonist SCH 58261 were administered in vivo at doses known to reduce infarct size and compared with the leukotriene biosynthesis inhibitor MK-886. 4 MK-886 (0.3 and 2 mg kg 71 i.v.) and MK-801 (3 mg kg 71 i.p.) decreased cysteinyl-leukotriene levels (778%, P50.05; 7100%, P50.01; 792%, P50.01, respectively) 4 h after permanent occlusion of the middle cerebral artery, whereas SCH 58261 (0.01 mg kg 71 i.v.) had no signi®cant eects. 5 MK-886 (2 mg kg 71 i.v.) was also able to signi®cantly reduce the cortical infarct size by 30% (P50.05). 6 We conclude that cysteinyl-leukotriene formation is associated with NMDA receptor activation, and that it represents a neurotoxic event, the inhibition of which is able to reduce brain infarct area in a focal ischaemic event.