Abstract-Recently a point mutation of guanine to thymine at nucleotide position 1917 in the endothelial nitric oxide synthase (eNOS) gene has been reported to be associated with coronary artery spasm. In addition, a significant association of the 4a/b polymorphism in intron 4 of the eNOS gene with coronary artery disease has been reported. However, the implications of these polymorphisms with respect to acute myocardial infarction (AMI) remain to be established. We conducted a case-control study of 226 patients with AMI and 357 healthy gender-and age-matched control subjects. In the former group, coronary angiograms were evaluated according to angiographic criteria based on the number of diseased vessels (Ն75%) and the number of stenotic lesions (Ն50%). Homozygosity for the Glu-Asp298 polymorphism existed in 5 of 226 patients with AMI (2.2%) but not in any of the 357 control subjects (Pϭ.0085). However, when we evaluated the coronary angiograms of 226 case patients, there was no difference in the number of diseased vessels or the number of stenotic lesions between the patients with this homozygote and those without it. By contrast, there was no evidence of a significant increase in the risk of AMI or the severity of coronary atherosclerosis among individuals with the a/a genotype of the eNOS4a/b polymorphism. Our results imply that patients who are homozygous for the Glu-Asp298 polymorphism may be genetically predisposed to AMI; however, this mutation apparently is not related to the severity of coronary atherosclerosis. Further studies are needed to confirm our results and characterize the molecular mechanisms by which eNOS is involved in susceptibility to AMI. (Hypertension. 1998;32:521-526.)Key Words: endothelium-derived relaxing factor Ⅲ genes Ⅲ myocardial infarction Ⅲ atherosclerosis Ⅲ angiography S ince the identification of nitric oxide (NO) as an important endothelium-derived relaxing factor, there has been an explosion of new information on the physiological and pathophysiological roles of NO. NO is synthesized from the amino acid L-arginine by a family of enzymes, referred to as NO synthase (NOS). Three distinct isoforms of NOS have been identified to date.1 The inducible NOS is expressed in vessel walls and macrophages by certain cytokines and endotoxin lipopolysaccharides in pathological conditions. 2The constitutive neuronal NOS is expressed in the central and peripheral nervous systems as well as in macula densa of kidney. It plays important roles in physiological 3 and pathophysiological 4 conditions. The constitutive endothelial NO synthase (eNOS) is expressed in the endothelium, where it produces NO from L-arginine. NO diffuses from the endothelium to the vascular smooth muscle cells, where it increases the concentration of cGMP by stimulating soluble guanylate cyclase, leading to vascular relaxation.

This trial demonstrated the beneficial effect of sour milk on BP in borderline hypertensive men who were not taking antihypertensive medication.

Published reports of 30 separate sets of analyses from 29 observational studies relating dietary intake of magnesium to blood pressure (BP) were identified through a comprehensive search using MEDLINE and BIDS-EMBASE. Three studies were prospective, 24 crosssectional (25 reports), of which four also contained a longitudinal component, and two were obtained from baseline data in a trial. Various dietary methodologies were used: 24-h dietary recall (n = 12), food-frequency questionnaire (8), food record (7), and duplicate diet (2). Twelve reports compared magnesium intake or BP level between subgroups. Seven showed a negative association between magnesium intake and BP level, and five reported no association. From 18 of the 30 sets of analyses either a regression estimate or a Pearson correlation coefficient was reported. Many reports also allowed identification of subgroups by sex, age and race. Ninety population samples and subgroups could

Our aim was to examine differences in dietary intake and blood pressure (BP) and their associations in four different ethnic Chinese populations, the Han, the Uygur, the Kazak and Tibetan subjects. This study used a sub-database of the Chinese sample of the WHO-Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. The WHO-CARDIAC Study was a multicenter cross-sectional study. In each center, 100 men and 100 women aged 48-56 years were selected at random from the local population. Various markers of dietary intake and their relation with BP were studied. The results of the present study indicated the following. 1) There were significant differences in mean BP and prevalence rates of hypertension, with both being higher in the Kazak and Tibetan subjects than in Han and Uygur subjects. 2) The highest mean body mass index (BMI) was observed in the Kazak subjects, while the highest 24-h urinary sodium (Na) and sodium to potassium (Na/K) ratio excretion were observed in the Tibetan subjects. There were also significant differences in other factors, such as magnesium, 3-methylhistidine (3MH) (a biological marker of animal protein intake) and taurine (a biological marker of seafood intake) excretion levels among the four ethnic peoples. 3) In general, BMI, Na and/or Na/K ratios were positively, and 3MH/creatinine and taurine/creatinine ratios were negatively associated with BP. 4) After adjustment for age, sex and potassium, subjects with obesity (BMI > or =26 kg/m2) had significantly higher relative risk of being hypertensive (HT) than those with BMI<26 kg/m2 in the Han, Uygur and Kazak populations; and subjects with elevated sodium excretion (Na > or =244 mmol/day) had significantly higher relative risk of being HT than those with Na<244 mmol/day in the Han, Uygur and Tibetan populations. In conclusion, mean BP and prevalence rates of hypertension were significantly different among the four ethnic groups. These differences are likely to be due, at least in part, to the differences in several diet-related factors, which in turn are associated with culture and environmental differences. Different health promotion strategies might thus be emphasized in different populations.