Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, has been implicated in regulating vascular tone and participating in chronic and acute kidney injury. However, little is known about the role of S1P in the renal microcirculation. Here, we directly assessed the vasoresponsiveness of preglomerular and postglomerular microvascular segments to exogenous S1P using the in vitro bloo...

Objective—The umbilical cord is a critical pathway between mothers and fetuses, and regulations of umbilical vessel tension are important for fetal growth. Shengmai is an herbal medicine being used in treatments of cardiovascular diseases. However, effects of Shengmai on human blood vessels and related pharmacological mechanisms are unclear. Methods—This study investigated the effects of relate...

Purine compounds modulate sympathetic neurotransmission; this modulation decreases nervous discharge by stimulating presynaptic inhibitory adenosine receptors, an effect antagonized by theophylline, and causes vasoconstriction through the stimulation of postsynaptic ATP receptors. In humans we evaluated the effect of local theophylline, which was infused into the brachial artery at the rate of ...

This study evaluates the vasoactive effects and mechanisms of action of serotonin on epicardial arteries in awake dogs chronically instrumented with miniature piezoelectric dimension crystals on the proximal circumflex coronary artery. Serotonin (2-16 micrograms) infused as a bolus in the left atrium effected a dose-related biphasic response, which was characterized by an initial increase in ve...

UNLABELLED Cyclooxygenase (COX) products play an important role in modulating sepsis and subsequent endothelial injury. We hypothesized that COX inhibitors may attenuate endothelial dysfunction during sepsis, as measured by receptor-mediated bradykinin (BK)-induced vasoconstriction and/or receptor-independent hypoxic pulmonary vasoconstriction (HPV). Rats were administered intraperitoneally a n...

In perfused rat skeletal muscle (hindlimb), capsaicin either stimulates (submicromolar concentrations) or inhibits (micromolar concentrations) oxygen consumption (VO2). Both VO2 effects are associated with vasoconstriction, evident as an increase in perfusion pressure (PP), under constant flow. We have proposed that these effects are mediated by two vanilloid receptor subtypes: VN1 (stimulation...