Effects of varying the intracellular adenosine triphosphate level on both the action potential and the membrane current were studied in single ventricular cells isolated from the guinea pig heart, using collagenase. Intracellular injection of adenosine triphosphate elevated the plateau potential level and prolonged the action potential duration. Similar results were obtained by injecting adenos...

Partial exchange transfusion with a cell-free hemoglobin (Hb) polymer during transient middle cerebral artery occlusion (MCAO) reduces infarct volume but fails to increase blood flow, as might be expected with the induced decrease in hematocrit. In ischemic brain, endothelin antagonists are known to produce vasodilation. In nonischemic brain, pial arterioles constrict after Hb exchange transfus...

Previous studies showed that a mixture, Coriaria Lactone (CL), extracted from a traditional Chinese herb Loranthus Parasiticus Mer, had a great excitatory influence on the nervous system, resulting in seizure. But what component in CL causes seizure is unclear. Tutin is a pure chemical component derived from CL. The present experiments were carried out to test if tutin has any epileptogenic act...

HEK 293 cells stably expressing the human serotonin transporter (hSERT) were grown on coverslips, preincubated with [(3)H]5-hydroxytryptamine (5-HT), and superfused. Substrates of the hSERT [e.g., p-chloroamphetamine (PCA)], increased the basal efflux of [(3)H]5-HT in a concentration-dependent manner. 5-HT reuptake blockers (e.g., imipramine, paroxetine) also raised [(3)H]5-HT efflux, reaching ...

Previous studies have demonstrated that low shear rates promote leukocyte adherence to microvascular endothelium in postcapillary venules. The objective of this study was to determine whether an accumulation of inflammatory mediators such as platelet activating factor and leukotriene B4 is responsible for shear rate-dependent leukocyte-endothelial cell adhesion. Postcapillary venules (25-39 mic...

Recent evidence indicates that elevated plasma levels of homocysteine are a risk factor for ischemic cerebrovascular diseases. However, little is known about cerebrovascular effects of homocysteine. Homocysteine could impair cerebrovascular function by metal-catalyzed production of activated oxygen species. We studied whether homocysteine, in the presence of Cu2+, alters reactivity of cerebral ...

The goal of this investigation was to measure changes in vascular permeability, pore cutoff size, and number of transvascular transport pathways as a function of time and in response to vascular endothelial growth factor (VEGF), placenta growth factor (PIGF-1 and PIGF-2), or basic fibroblast growth factor (bFGF). Two human and two murine tumors were implanted in the dorsal skin chamber or crani...

Central sensitization represents a sustained hypersensitive state of dorsal horn nociceptive neurons that can be evoked by peripheral inflammation or injury to nerves and tissues. It reflects neuroplastic changes such as increases in neuronal spontaneous activity, receptive field size and responses to suprathreshold stimuli, and a decrease in activation threshold. We recently demonstrated that ...

Superfusion of the squid giant synapse with artificial seawater (ASW) based on isotonic saline containing oxygen nanobubbles (RNS60 ASW) generates an enhancement of synaptic transmission. This was determined by examining the postsynaptic response to single and repetitive presynaptic spike activation, spontaneous transmitter release, and presynaptic voltage clamp studies. In the presence of RNS6...

We have compared the effects of lidocaine (L) to those of several derivatives in an attempt to determine the sites of action and active forms of the molecules. We studied cardiac Purkinje fibers with intracellular microelectrodes, and drugs were administered by superfusion or by iontophoretic intracellular injection. We compared to L the effects of QX-314 and QX-572, two quaternary derivatives,...