Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.21 (CPT)
 4,580 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-activating factor (PAF) is implicated in human immunodeficiency virus (HIV)-related manifestations. Increased PAF synthesis has been recently detected in HIV-infected patients. In this study, we examined in naive HIV-infected patients the in vivo effects of a highly active antiretroviral therapy (HAART) regimen, containing tenofovir-DF/emtricitabine/efavirenz, on PAF metabolism. The specific activities of PAF basic biosynthetic enzymes, PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (lyso-PAF-AT), but also the ones of PAF-basic catabolic enzymes, PAF acetylhydrolase (PAF-AH) in leukocytes and platelets, and lipoprotein-associated-phospholipase-A(2) (LpPLA(2)) in plasma, were measured in blood samples of eight asymptomatic naive male HIV-infected patients just before and after 1, 3, and 6 months of treatment. CD4 cell counts, viral load, and several biochemical markers were also measured in the same blood samples of these patients. The repeated measures ANOVA and the Pearson r criterion were used to study statistical differences and correlations-partial correlations, while linear mixed models were conducted in order to estimate association(s) between time-dependent changes in these factors. Before treatment, the activities of PAF-CPT in leukocytes and LpPLA(2) in plasma were found to be inversely correlated with CD4 cell counts and positively correlated with the viral load. After 6 months of treatment, the activities of basic PAF-biosynthetic enzymes, PAF-CPT and lyso-PAF-AT, were both reduced in leukocytes. At 6 months, PAF-AH activity was also reduced in these cells, while LpPLA(2) remained stable. The reduction of PAF-CPT occurred even from the first month, while there is a time-dependent correlation between the increase of CD4 and the decrease of both viral load and PAF-CPT of leukocytes during treatment. Apart from its classical antiretroviral activities the tenofovir-DF/emtricitabine/efavirenz regimen also exhibited favorable effects on PAF metabolism and therefore may also display beneficial effects in some HIV-related conditions, such as cardiovascular disease (CVD), in which PAF is implicated.
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PMID:Effects of HAART on platelet-activating factor metabolism in naive HIV-infected patients I: study of the tenofovir-DF/emtricitabine/efavirenz HAART regimen. 2205 Jun 95

A number of studies support the anti-atherogenic effect of wine compounds. The scope of this study was to examine the effect of a red (Cabernet Sauvignon-CS) and a white (Robola-R) wine, as well as resveratrol and quercetin, on the platelet activating factor (PAF) biosynthetic enzymes, acetyl-CoA:lyso-PAF acetyltransferase (lyso-PAF-AT) and DTT-insensitive CDP-choline 1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT), and its main catabolic enzyme (PAF acetylhydrolase; PAF-AH), on U937 cells, in cell free and in intact cell experiments. In cell free experiments, phenolic compounds and wine extracts inhibited PAF biosynthetic enzymes, however in higher concentrations than intact cell experiments. In the latter cases, polar lipids of both wines inhibited in the same order of magnitude the action of lyso-PAF-AT and of PAF-CPT. The water fractions possessed a dual action, in lower concentrations they activated both enzymes, while in higher concentrations only inhibited PAF-CPT. All fractions either did not affect or slightly activated PAF-AH activity. In conclusion, wine compounds may exert their anti-inflammatory activity by reducing PAF levels through modulation of the PAF metabolic enzymes.
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PMID:Effect of Robola and Cabernet Sauvignon extracts on platelet activating factor enzymes activity on U937 cells. 2503 48