Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.15.1 (ACE)
 18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the treatment of patients with symptomatic coronary artery disease using PTCA, success is limited due to restenosis rates ranging from 30-50% of the lesions treated. Medical approaches to reduce the rate of restenosis were therefore tested in a number of trials. However, in only a few randomized and controlled trials were positive effects reported. Inhibiting platelet aggregation through the use of anti-glycoprotein IIb/IIIa monoclonal antibody 7E3 and, in some studies, with 3 omega fatty acids, a significant reduction in the rate of restenosis was observed. Many trials testing less potent inhibitors of platelet aggregation, such as acetylsalicylic acid, prostacyclin, thromboxane A2 receptor antagonists, and ticlopidine as well as anticoagulants such as heparin or coumarin, calcium antagonists, ACE-inhibitors, antiproliferative agents such as colchicine, methylprednisolone, and angiopeptin were inconclusive or without a positive treatment effect. The results of a hirudin multicenter trial on the rate of restenosis (Helvetica Trial) will soon be reported. There are many possible reasons for these disappointing results, such as poor standardization of the invasive studies, in analyzing the degree of coronary artery stenoses, the inadequate sample size in many trials, and insufficient local drug concentrations as well as the lack of beneficial effects of the study medication. Thus, at present there is no effective treatment to reduce the restenosis rate following PTCA. However, it can be expected that potent antithrombins, or inhibitors of platelet aggregation, may be useful.
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PMID:[Modification of re-stenosis with drugs]. 785 79

Bradykinin is a mediator of the protection of myocardium by angiotensin I-converting enzyme/kininase II inhibitors. We reported that the activation of B2 bradykinin receptors in neonatal rat cardiac myocytes in primary culture was followed by hydrolysis of phosphatidylinositol 4,5-bisphosphate and formation of inositol 1,4,5-trisphosphate (IP3). Here we examine the regulation of IP3 formation stimulated by bradykinin. Activation of myocytes with 1 mu/L bradykinin increased IP3 production from 117 +/- 8.3 to 1011 +/- 48.6 pmol/mg protein. Treatment of the cells with 10 mu/L indomethacin or 1 mu/L dexamethasone partially blocked this bradykinin-induced response. Moreover, either U73122, a phospholipase C inhibitor, or (p-amylcinnamoyl) anthranilic acid, a phospholipase A2 inhibitor, blunted the IP3 response to bradykinin. Because thromboxane A2 stimulates inositol bisphosphate metabolism in guinea pig atria, we also investigated the effect of the thromboxane A2 receptor antagonist BM 13177 (1 mu/L), which strongly attenuated the stimulated IP3 production. Since thromboxane A2 appears to partly mediate the IP3 response to bradykinin, we examined the effect of the stable thromboxane A2 mimetic U46619. Control cultures were stimulated more by U46619 than by bradykinin (1629 +/- 14.5 versus 1011 +/- 48.6 pmol IP3/mg protein). This property of U46619 was selectively antagonized by BM 13177. Inhibition of either phospholipase C or phospholipase A2 blunted the IP3 response to U46619. Short-term (30 minutes) activation of protein kinase C with phorbol 12-myristate 13-acetate (10 pmol/L to 1 mu/L) attenuated the IP3 accumulation in response to bradykinin; the effect of phorbol 12-myristate 13-acetate was reversed with 1 mu/L staurosporine, a protein kinase C inhibitor. Treatment with 1 microgram/mL cholera toxin or pertussis toxin for 4 hours amplified the IP3 response to 10 nmol/L bradykinin from 570 +/- 20.0 to 1150 +/- 51.3 and to 1016.7 +/- 21.9 pmol/mg protein. Bradykinin mobilized 9.4% of intracellular calcium stores in cardiomyocytes as assessed by chlortetracycline-based fluorometry, and this effect of bradykinin was blocked by BM 13177 or the B2 bradykinin receptor blocker Hoe 140 by more than 70%. In functional studies, bradykinin (1 mu/L) increased by 12% the twitch contractile force of neonatal rat ventricular strips paced at threshold intensity, but this was unaffected by BM 13177. In conclusion, in cardiomyocytes, bradykinin enhances IP3 production mostly via phospholipase A2 stimulation and thromboxane A2 formation. This prostanoid in turn stimulates its receptor and activates phospholipase C, which then splits phosphatidylinositol 4,5-bisphosphate into IP3 and diacylglycerol. The effect of bradykinin on phospholipase C, via thromboxane A2, is negatively regulated by protein kinase C activation.
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PMID:Thromboxane A2 mediates the stimulation of inositol 1,4,5-trisphosphate production and intracellular calcium mobilization by bradykinin in neonatal rat ventricular cardiomyocytes. 879 31

A large number of drug trials for prevention of restenosis have been conducted with many showing little or conflicting benefit. Antiplatelets such as aspirin, ticlopidine and thromboxane A2 receptor inhibitors have not shown a clear benefit. Similarly, antithrombotics, either acting indirectly such as heparin, or as direct thrombin inhibitors such as hirudin and hirulog, do not prevent restenosis. Trials with ACE inhibitors, HMG-CoA reductase inhibitors and fish-oil supplements have yielded inconclusive results. The antiproliferatives, angiopeptin, trapidil and tranilast have shown some benefit in small-scale studies. Other drug classes of potential benefit include the glycoprotein IIb/IIIa receptor antagonists, inhibitors of the early coagulation cascade, calcium channel blockers and nitric oxide donors. Drug research into restenosis prevention has been hampered by problems with the definition of restenosis and the applicability in humans of animal models. Although no single drug has conclusively proven effective yet, the promise of a number of agents, together with other nonpharmacological strategies will likely result in further reductions in the incidence of restenosis.
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PMID:Pharmacological approaches for the prevention of restenosis after percutaneous coronary intervention. 932 30