Background--Hypertension is one of the main comorbidities associated with dyslipidemia. This study aimed to examine the extent to which dyslipidemia increases the risk of developing hypertension in a Japanese working-age male population.
Abstract-Cyclooxygenase-2 (COX-2) is known to mediate the cardioprotective effects of the late phase of ischemic preconditioning (PC); however, the signaling pathways involved in COX-2 induction following ischemic PC are unknown. In addition, although inducible nitric oxide synthase (iNOS) has been identified as a co-mediator of late PC together with COX-2, the interaction between iNOS and COX-2 in the heart is unknown. Using conscious rabbits, we found that the induction of COX-2 expression 24 hours after ischemic PC was blocked by pretreatment with inhibitors of protein kinase C (PKC), Src protein tyrosine kinases (PTKs), and nuclear factor-B (NF-B) but not by inhibitors of NOS or scavengers of reactive oxygen species (ROS). The selective iNOS inhibitors SMT and 1400W, given 24 hours after PC, abrogated the increase in myocardial prostaglandin E 2 (PGE 2 ) and 6-keto-PGF 1␣ , whereas the selective soluble guanylate cyclase inhibitor ODQ had no effect. COX-2 selective inhibitors (celecoxib and NS-398) did not affect iNOS activity. These results demonstrate that (i) ischemic PC upregulates cardiac COX-2 via PKC-, Src PTK-, and NF-B-dependent signaling pathways, whereas generation of NO and ROS is not necessary, and (ii) the activity of newly synthesized COX-2 following PC requires iNOS-derived NO whereas iNOS activity is independent of COX-2-derived prostanoids, indicating that COX-2 is located downstream of iNOS in the protective pathway of late PC. The data also indicate that iNOS modulates COX-2 activity via cGMP-independent mechanisms. To our knowledge, this is the first demonstration that iNOS-derived NO drives prostanoid synthesis by COX-2 in the heart. NO-mediated activation of COX-2 may be a heretofore unrecognized mechanism by which NO exerts its salubrious effects in the late phase of PC. (Circ Res. 2002;90:602-608.)
Music therapy (MT) has been used in geriatric nursing hospitals, but there has been no extensive research into whether it actually has beneficial effects on elderly patients with cerebrovascular disease (CVD) and dementia. We investigated the effects of MT on the autonomic nervous system and plasma cytokine and catecholamine levels in elderly patients with CVD and dementia, since these are related to aging and chronic geriatric disease. We also investigated the effects of MT on congestive heart failure (CHF) events.Eighty-seven patients with pre-existing CVD were enrolled in the study. We assigned patients into an MT group (n = 55) and non-MT group (n = 32). The MT group received MT at least once per week for 45 minutes over 10 times. Cardiac autonomic activity was assessed by heart rate variability (HRV). We measured plasma cytokine and catecholamine levels in both the MT group and non-MT group. We compared the incidence of CHF events between these two groups. In the MT group, rMSSD, pNN50, and HF were significantly increased by MT, whereas LF/HF was slightly decreased. In the non-MT group, there were no significant changes in any HRV parameters. Among cytokines, plasma interleukin-6 (IL-6) in the MT group was significantly lower than those in the non-MT group. Plasma adrenaline and noradrenaline levels were significantly lower in the MT group than in the non-MT group. CHF events were less frequent in the MT group than in the non-MT group (P < 0.05). These findings suggest that MT enhanced parasympathetic activities and decreased CHF by reducing plasma cytokine and catecholamine levels.
Abstract-Aldose reductase (AR), a member of the aldo-keto reductase superfamily, has been shown to metabolize toxic aldehydes generated by lipid peroxidation, suggesting that it may serve as an antioxidant defense. To investigate its role in the late phase of ischemic preconditioning (PC), conscious rabbits underwent 6 cycles of 4-minute coronary occlusion/4-minute reperfusion. Twenty-four hours later, there was a marked increase in AR protein and activity and in the myocardial content of sorbitol, a unique product of AR catalysis. Pretreatment with N -nitro-L-arginine, a nitric oxide synthase inhibitor, or chelerythrine, a protein kinase C inhibitor (both given at doses that block late PC in this model), prevented the increase in AR protein 24 hours later, demonstrating that ischemic PC upregulates AR via nitric oxide-and protein kinase C-dependent signaling pathways. The AR-selective inhibitors tolrestat and sorbinil prevented AR-mediated accumulation of sorbitol and abrogated the infarct-sparing effect of late PC, demonstrating that enhanced AR activity is necessary for this cardioprotective phenomenon to occur. Inhibition of AR did not affect infarct size or the myocardial accumulation of the lipid peroxidation product 4-hydroxy trans-2-nonenal (HNE) in nonpreconditioned rabbits. The accumulation of HNE was inhibited by late PC, and this effect was abrogated by sorbinil. Taken together, these results establish AR as an essential mediator of late PC. Furthermore, the data suggest that myocardial ischemia/reperfusion injury is due in part to the generation of lipid peroxidation products and that late PC diminishes this source of injury by upregulating AR. Key Words: myocardial ischemia/reperfusion injury Ⅲ aldose reductase Ⅲ myocardial infarction Ⅲ 4-hydroxy-trans-2-nonenal Ⅲ ischemic preconditioning A ldose reductase (AR) is a member of the aldo-keto reductase superfamily. 1 Although this enzyme is expressed in most eukaryotic cells and is known to catalyze the reduction of a several aldehydes including aldo-sugars, its physiological role remains unclear. 2 Recent investigations have shown that AR exhibits high affinity for hydrophobic aldehydes, such as those generated during lipid peroxidation. 3 The most abundant among the lipid-derived aldehydes, 4-hydroxy trans-2-nonenal (HNE) and its glutathione conjugate, are excellent substrates of AR. 3 Because lipid-derived aldehydes are cytotoxic, 4 the ability of AR to metabolize them suggests that this enzyme may be involved in protection against oxidative injury. This function of AR could be important in myocardial ischemia/reperfusion, which is associated with increased generation of reactive oxygen species. 5 Indeed, mounting evidence indicates that HNE is a major product of lipid peroxidation during myocardial ischemia/ reperfusion 6 and that the formation of HNE and the accumulation of HNE-modified proteins are related to the extent of tissue damage. 7,8 The late phase of ischemic preconditioning (PC) is a long-lasting adaptive response of the myocardium...
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