The association of plasma homocysteine, coronary risk factors and serum nitrite in patients with coronary artery disease, vascular syndrome x and healthy subjects.

OBJECTIVE: We evaluated the association of plasma total homocysteine (tHcy), cardiac risk factors and total nitrite in coronary artery disease (CAD) patients, cardiac syndrome X patients and in healthy subjects. METHODS: Forty two CAD, 22 cardiac syndrome X patients and 30 healthy subjects, aged 30 to 75 years were included into the study. Blood samples of tHcy, serum total nitrite and cardiac risk factors were studied appropriately. The results were compared between the groups. The independent contributions of tHcy and total nitrite to CAD and cardiac syndrome X and their interactions with cardiac risk factors were evaluated. RESULTS: After adjusting for age, median values of tHcy and total nitrite were evaluated for their skewness. Coronary artery disease patients had higher median plasma tHcy levels than cardiac syndrome X patients (p<0.001) and healthy subjects (p<0.001) and lower serum total nitrite levels than patients in the two other groups (p<0.05), respectively. Using a univariate linear regression analysis tHcy had a moderately significant positive correlation with age (beta=0.34, p=0.002) and a weakly significant inverse correlation with female gender (beta=-0.24, p=0.032). Using a partial correlation analysis by controlling for age, gender and clinical situations tHcy had a positive but moderately significant correlation with LDL cholesterol (r=0.23, p=0.01) and triglycerides (r=0.27, p=0.016). Total nitrite had a positive but weakly significant correlation with HDL cholesterol (r=0.23, p=0.04) and fibrinogen (r=0.24, p=0.03) and an inverse but moderately significant correlation with LDL cholesterol (r=-0.37,p=0.001). Using a multivariate stepwise regression analysis total nitrite was inversely and significantly associated with tHcy (beta=-0.45) in the control group. The contribution of HDL cholesterol to the association was beta=-0.45, p=0.044, R2=36.2%, HDL cholesterol with fibrinogen--beta=-0.45, p=0.05, R2=36.6% and HDL cholesterol with LDL cholesterol--beta=-0.45, p=0.05, R2=36.3%. In a forward stepwise logistic regression analysis the age adjusted odds ratio (OR) for coronary artery disease per standard deviation change in log-transformed tHcy concentration was - 0.82, p=0.013 and in total nitrite concentration was - 1.08, p=0.02. Using the same model neither tHcy nor total nitrite was associated with cardiac syndrome X (p=0.221 and p=0.112), respectively. CONCLUSION: The low nitrite levels can be a marker of endothelial dysfunction in the presence of hyperhomocysteinemia and other cardiac risk factors. Our results might support endothelial dysfunction in CAD but not in cardiac syndrome X patients.

L-carnitine does not exert any in vitro relaxant effect in Guinea pig trachea, lung parenchyma and human bronchial tissue.

The aim of the present study was to investigate the probable in vitro relaxant effect of carnitine in guinea pig trachea, guinea pig lung parenchymal strips, and human bronchial tissue. It was suggested by an in vivo study that carnitine pretreatment prevented the subclinic bronchospasm in children who underwent chronic hemodialysis. Tracheal and lung parenchymal preparations of 10 guinea pigs and 5 human bronchial tissues were prepared and mounted in 20-mL organ baths. In the first series of experiments, contractions to carbachol and histamine (10(-9) to 10(-3) M) were compared after the tissues were incubated with different concentrations of L-carnitine (10(-6) to 10(-4) M). pD(2) values were compared with analysis of variance (ANOVA) and P <.05 was considered as significant. In the second part of experiments, the inhibitory effect of L-carnitine (10(-9) to 10(-3) M) was investigated on the sustained contractions of preparations to carbachol (10(-6) M) and histamine (10(-5) M). In the first part of the study pD(2) values obtained with carbachol were 6.48 +/- 0.09, 5.42 +/- 0.05, and 6.48 +/- 0.02 for guinea pig trachea, guinea pig lung parenchymal strips, and human bronchial tissues, respectively. pD(2) values obtained with histamine were 5.34 +/- 0.10, 5.74 +/- 0.06, and 6.32 +/- 0.03 for guinea pig trachea, guinea pig lung parenchymal strips, and human bronchial tissues, respectively. No significant difference was observed between the pD(2) values before and after incubation with carnitine (P >.05). In the second part of the study, only 10(-4) M L-carnitine exerted an insignificant relaxant effect (6.16% +/- 1.22% on carbachol induced contractions and 4.48% +/- 0.85% on histamine induced contractions) in guinea pig trachea. Our results show that L-carnitine exerts no in vitro relaxant effect in guinea pig trachea, guinea pig lung parenchymal strips, and human bronchial preparations.

Hypericum triquetrifolium Turra. Extract exhibits antiinflammatory activity in the rat.

The aim of the present study was to explore the probable antiinflammatory effect of Hypericum triquetrifolium Turra. in a rat model of carrageenan induced inflammation. Male Wistar rats were treated intraperitoneally with 0.4% dimethylsulphoxide (DMSO) (as control group) and H. triquetrifolium extract (25, 50, 60 mg/kg), 30 min before 0.1 ml 1% carrageenan injection. Paw volume was measured before and 1, 2, 3, 4, 5 and 6 h after the injection of carrageenan. The results are expressed as the mean+/-s.e. mean and the statistical significance of differences between groups was analyzed by One Way Analysis of Variance (ANOVA). The intraplantar injection of carrageenan caused a time-dependent paw edema in the rat although saline injection caused no swelling. Intraperitoneal administration of H. triquetrifolium extract (25, 50, 60 mg/kg) inhibited paw swelling dose-dependently at 2, 3, 4, 5 and 6 h after carrageenan injection (P<0.05). We can conclude that H. triquetrifolium extract may exert an antiinflammatory effect in rats.