Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have measured activity of platelet-activating factor (PAF) acetylhydrolase, an enzyme that specifically inactivates PAF, in plasma from patients with essential hypertension and healthy controls. The average activities in 34 patients and 22 controls were 113 +/- 60 and 79 +/- 32 nmol/ml/min, respectively, and the difference was significant (p less than 0.05). Approximately three fourths of the total plasma activity was recovered in LDL, with the remainder in HDL; and there was a significant difference in the activity associated with the LDL between patients and controls. The relative distribution of the activity among lipoproteins was almost equal in the two groups, and there was no difference in plasma lipids or apoproteins between them. In patients there was a tendency for plasma PAF acetylhydrolase activity to increase with the length of the history of hypertension. Further studies are needed to distinguish between a number of reasons for increased levels of plasma PAF acetylhydrolase in essential hypertension.
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PMID:Increased activity of the platelet-activating factor acetylhydrolase in plasma low density lipoprotein from patients with essential hypertension. 277 20

The prevalence of plasma platelet-activating factor (PAF) acetylhydrolase deficiency was investigated in 477 healthy Japanese individuals and 985 patients with various cardiovascular diseases. The genotype for this enzyme with regard to a G994-->T mutation (MM, normal; Mm, heterozygote; mm, mutant homozygote) was determined by an allele-specific polymerase chain reaction in 80 subjects shown to have no or low plasma activity (<10 nmol/min/ml). In 72 subjects, the genotype was consistent with plasma enzyme activity; 44 individuals with no activity were mm, and 28 with low activity were Mm. However, eight subjects with the MM genotype showed plasma enzyme activities of <10 nmol/min/ml. Determination of the DNA sequence of exon 9 of the plasma PAF acetylhydrolase gene in these eight subjects revealed a previously unidentified A1001-->G missense mutation, resulting in a Gln281-->Arg substitution, in a 72-year-old woman with coronary artery disease, essential hypertension, and no plasma enzyme activity. Site-directed mutagenesis in vitro showed that the corresponding recombinant mutant protein lacked PAF acetylhydrolase activity. Thus, the Gln281-->Arg substitution appears responsible for the loss of plasma PAF acetylhydrolase activity.
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PMID:Loss of activity of plasma platelet-activating factor acetylhydrolase due to a novel Gln281-->Arg mutation. 924 31

Platelet-activating factor (PAF) acetylhydrolase is an enzyme that inactivates PAF. Deficiency of this enzyme is caused by a missense mutation in the gene. We previously found a higher prevalence of this mutation in patients with ischemic stroke. This fact suggests that the mutation might enhance the risk for stroke through its association with hypertension. We have addressed this hypothesis by analyzing the prevalence of the mutation in hypertension. We studied 138 patients with essential hypertension, 99 patients with brain hemorrhage, and 270 healthy controls. Genomic DNA was analyzed for the mutant allele by the polymerase-chain reaction. The prevalence of the mutation was 29.3% (27.4% heterozygotes and 1.9% homozygotes) in controls and 36.2% in hypertensives and the difference was not significant. The prevalence in patients with brain hemorrhage was significantly higher than the control: 32.6% heterozygotes and 6.1% homozygotes (p <0.05). PAF acetylhydrolase deficiency may be a genetic risk factor for vascular diseases.
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PMID:A mutation in plasma platelet-activating factor acetylhydrolase (Val279Phe) is a genetic risk factor for cerebral hemorrhage but not for hypertension. 975 12

Platelet-activating factor (PAF) is a phospholipid mediator with a wide range of potent biological activities. The molecular structure of PAF is identified as 1-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine and it is degraded by the enzyme PAF acetylhydrolase (PAF-AH), which removes the sn-2 acetyl moiety of the molecule. Plasma PAF-AH activity is elevated in various disorders, including stroke, and this is considered an adaptation to the enhanced inflammatory or thrombotic processes in such disorders. Deficiency of plasma PAF-AH occurs due to a missense mutation (G994-->C) in exon 9 of the PAF-AH gene, which results in a Val-->Phe substitution at position 279 of the mature enzyme protein. This mutation is found in about 4% of the general Japanese population. However, it is not specifically related to any particular disease. The prevalence of plasma PAF-AH deficiency and the frequency of mutant alleles are significantly higher in patients suffering from stroke as compared to healthy controls. The prevalence of the mutation was similar in the groups of patients with atherothrombotic infarction and intracerebral hemorrhage. There was no difference in the prevalence of the mutation in the patients with essential hypertension as compared to that in healthy in controls. Therefore plasma PAF-AH deficiency may be considered as a genetic risk factor for stroke, and recognition of this mutation in individuals may be useful for early initiation of preventive measures against stroke.
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PMID:[Plasma platelet-activating factor acetylhydrolase (PAF-AH) deficiency as a risk factor for stroke]. 1906 65