Mechanism of the relaxant effect of rosuvastatin lactone on rat aortic rings.

The relaxant effect of the lactone of rosuvastatin was evaluated on aortic rings from male Wistar rats (250-300 g) with and without endothelium, precontracted with 1.0 microM phenylephrine. The lactone presented a greater potency than rosuvastatin in relaxing aortic rings.

Vitamin D receptor gene, biochemical bone markers and bone mineral density in Mexican women on dialysis.

Background: The influence of the Bsm1 polymorphism of the vitamin D receptor (VDR) gene on mineral and bone disorders in chronic kidney disease (CKD) is still under discussion. The aim of this study was to analyse the relationship between VDR polymorphism, bone mineral density (BMD), biochemical bone markers and clinical factors in women on peritoneal dialysis (PD) and haemodialysis (HD).

Methods: In a cross-sectional study, 197 women (42 +/- 10 years; 25% with diabetes mellitus (DM); body mass index (BMI) 25.

Influence of triiodothyronine on the contractile effect of D-nor-pseudoephedrine.

Here we contrast the vascular smooth muscle contractility produced by D-nor-pseudoephedrine, alone or combined with triiodothyronine, on the aorta and coronary vasculature of the rat. At high concentrations (greater than those found in normal therapeutic dosing) D-nor-pseudoephedrine contracted the aorta. In contrast, it produced vasodilation on pre-contracted aorta independently of the vasoconstrictor employed or the presence of vascular endothelium.

Age-related differences in the beta-adrenergic vasodilator response in rat aortic rings.

Mechanisms underlying age-dependent changes in vasodilator responses to beta-adrenergic drugs are poorly understood. The aim of the current study was to compare responses to isoproterenol (a non-selective beta-adrenergic receptor agonist) in phenylephrine or KCl precontracted aortic rings from 3 week and 3 month old male Wistar rats. Both the mechanism and the subtype of beta-adrenergic receptor underlying the response to isoproterenol in the both age groups were examined.

The influence of constitutive COX-2 in smooth muscle tissue on the contractile effect of phenylephrine in the rat abdominal aorta.

Prostanoids are involved in the phenylephrine-induced contraction of the aorta. Here, we examined whether or not constitutive cyclooxygenase-2 (phosholipases C and A2) is the source of prostanoids in the smooth muscle of the arterial wall of the thoracic and abdominal aorta. Both cyclooxygenase isoforms (COX-1 and COX-2) were expressed in the two aortic segments, but their expression was not altered by phenylephrine, the protein synthesis inhibitor cycloheximide, or the phospholipase A2 inhibitors arachidonyl trifluoromethyl ketone and methyl arachidonyl fluorophosponate.

Bioassay-guided isolation of an anti-ulcer chromene from Eupatorium aschenbornianum: role of nitric oxide, prostaglandins and sulfydryls.

Eupatorium aschenbornianum is considered useful in the treatment of gastric ulcer. In the current study the validity of this practice was tested by using the experimental model of an ethanol induced gastric ulcer in rats. The results show that E.

Enhancement of embryonic stem cell differentiation promoted by avian chorioallantoic membranes.

Avian chorioallantoic membrane (CAM) has been used as a model to explore angiogenesis and to study the microvasculature of transplanted tissues. Because CAM provides a vascular bed, cells can be implanted, and their development can be monitored and modified. We used the CAM model to study the differentiation process of embryoid bodies (EBs) derived from mouse embryonic stem cells (ESCs) influenced by the CAM vascular bed.

Bioassay-guided isolation of an anti-ulcer diterpenoid from Croton reflexifolius: role of nitric oxide, prostaglandins and sulfhydryls.

Croton reflexifolius H. B. K (Euphorbiaceae) is a very common medicinal plant in the Huastecan region of Mexico that, according to local folk medicine, is considered useful in the treatment of gastritis and gastric ulcer.

Kidney damage after renal ablation is worsened in endothelial nitric oxide synthase -/- mice and improved by combined administration of L-arginine and antioxidants.

Aim: Reduction in nitric oxide (NO) levels during kidney failure has been related to the reaction of NO with superoxide anions to yield peroxynitrite which possesses the biological activity responsible for renal damage. However, stimulation of the NO pathway ameliorates the progression of kidney failure. Thus, it is unclear whether NO prevents or acts as the compound responsible for the cytotoxicity observed during kidney failure.

Relaxant action mechanism of berberine identified as the active principle of Argemone ochroleuca Sweet in guinea-pig tracheal smooth muscle.

In this study we investigated the relaxant effect of the aerial parts of Argemone ochroleuca (Papaveraceae), which is used in Mexican traditional medicine for the treatment of various respiratory diseases such as cough, bronchitis and asthma. The alkaloid berberine was identified as one of the active relaxant principles (EC50 = 118.50 +/-3.

Mechanisms of relaxant action of a crude hexane extract of Gnaphalium liebmannii in guinea pig tracheal smooth muscle.

We investigated the mechanisms of action of Gnaphalium liebmannii which is used as a folk medicine in México for treating various respiratory diseases such as gripe, fever, asthma, cough, cold, bronchitis, expectorating, and bronchial affections. The tension changes of guinea pig tracheal segments were isometrically recorder on a polygraph. Hexane extract of Gnaphalium liebmannii was the most active relaxant extract (IC(30)=54.

Nerve root degeneration and regeneration by intrathecal phenol in rats: a morphologic approach.

Intrathecal injection of phenol (ITP) has been used to control intractable pain and spasticity. Direct caustic nerve damage has been postulated as the mechanism of analgesia. Sensation is commonly recovered, suggesting that a spontaneous regeneration process takes place.

[Intracellular calcium-dependent contractile effects of serotonin in the human umbilical artery].

Background: Absence of innervation is a hallmark of human umbilical vessels. Intervillous space blood flow is regulated by vasoactive substances and calcium dependent contractility, both in normal and pathological conditions such as preeclampsia-eclampsia.

Objective: To obtain additional information on the intracellular calcium contractile effects of serotonin in human umbilical arteries.

Ozone exposure induces iNOS expression and tyrosine nitration in rat aorta.

The aim was to study whether ozone affects vascular endothelium by causing inducible nitric oxide synthase (iNOS) expression and tyrosine nitration. We also studied biomarkers of endothelial function. Male Wistar rats were exposed to ozone (0.

Nitric oxide synthase in Entamoeba histolytica: its effect on rat aortic rings.

NADPH-diaphorase activity has been considered as a nitric oxide synthase (NOS) marker. Therefore, the presence of NADPH-d activity in Entamoeba histolytica suggests that they have NOS activity. The aim of this work was to provide support for this contention.

Synthesis and evaluation of the cardiovascular effects of two, membrane impermeant, macromolecular complexes of dextran-testosterone.

The incidence of cardiovascular disease is greater in men than in premenopausal women. Testosterone has been considered a significant risk factor for cardiovascular disease, but testosterone's mechanism of action and its cellular site of action are still not clear. However, it is likely that non-genomic extracellular effects of the hormone are involved.