d-ribose improves cardiac contractility and hemodynamics, and reduces expression of c-fos in the hippocampus during sustained slow ventricular tachycardia in rats

Modulation of intracellular ATP determines adenosine release and functional outcome in response to metabolic stress in rat hippocampal slices and cerebellar granule cells

Cerebral ischaemia rapidly depletes cellular ATP. Whilst this deprives brain tissue of a valuable energy source, the concomitant production of adenosine mitigates the damaging effects of energy failure by suppressing neuronal activity. However, the production of adenosine and other metabolites, and their loss across the blood-brain barrier, deprives the brain of substrates for the purine salvage pathway, the primary means by which the brain makes ATP. Because of this, cerebral ATP levels remain depressed after brain injury. To test whether manipulating cellular ATP levels in brain tissue could affect functional neuronal outcomes in response to oxygen/glucose deprivation (OGD), we examined the effects of creatine and d-ribose and adenine (RibAde). In hippocampal slices creatine delayed ATP breakdown, reduced adenosine release, retarded both the depression of synaptic transmission and the anoxic depolarization caused by OGD, and improved the recovery of transmission. In contrast, RibAde increased cellular ATP, caused increased OGD-induced adenosine release and accelerated the depression of synaptic transmission, but did not improve functional recovery. However, RibAde improved the viability of cerebellar granule cells when administered after OGD. Our data indicate that RibAde may be effective in promoting recovery of brain tissue after injury, potentially via enhancement of salvage-mediated ATP production.

The effect of c-fos on acute myocardial infarction and the significance of metoprolol intervention in a rat model

Over-expression of c-fos may play a role in some diseases. Research pertaining to the expression of c-fos in acute myocardial ınfarction (AMI) is rare, and the detailed role of c-fos in AMI has not been reported. Therefore, the purpose of this project was to elucidate the detailed effect of c-fos on AMI rats and evaluate the effect of a metoprolol intervention. An AMI rat model was established for the purposes of this study. The expression of c-fos in AMI was evaluated via immunohistochemical analysis and in situ hybridization. Simultaneously, we investigated the effect of c-fos on AMI rats via medicinal treatment with c-fos monoclonal antibody, isoproterenol, and metoprolol. Positive c-Fos protein expression and c-fos mRNA expression in cardiomyocytes were increased at 1, 3, 7, and 10 days after ligation in AMI rats compared with a sham-operated group. Peak expression occurred at 3 days after ligation. The weight percentage fraction of infarct size was decreased in rats treated with c-fos monoclonal antibody compared with the control normal saline treatment group. The weight percentage fraction of infarction size was increased after c-fos was increased via the administration of isoproterenol. c-Fos protein expression and the infarct size in rats treated with metoprolol were also decreased compared with the control normal saline treatment group. The results showed that c-fos expression rapidly increased after coronary ligation; c-fos plays an important role in myocardial lesions and is likely to be involved in the pathogenesis of AMI as well. Metoprolol can inhibit the expression of c-fos and has a positive therapeutic effect on rats after AMI; the involvement effect of metoprolol on myocardial infarction might be correlated with its effect on the inhibition of c-fos.