RATIONALE Reactive hyperemia (RH) in the forearm circulation is an important marker of cardiovascular health, yet the underlying vasodilator signaling pathways are controversial and thus remain unclear. OBJECTIVE We hypothesized that RH occurs via activation of inwardly rectifying potassium (KIR) channels and Na(+)/K(+)-ATPase and is largely independent of the combined production of the endot...

Zingiberis Rhizoma (Shokyo, [Japanese characters: see text]) showed significant ameliorative effect on the BaCl2-induced delay of gastric emptying in rat. Bioassay-guided fractionation of the aqueous extract of Shokyo resulted in isolation of 6-gingesulfonic acid (1) and shogasulfonic acid A (3). These compounds significantly improved the delay of gastric emptying on both BaCl2-induced and N(G)...

Addition of BaCl2 to the solution bathing colons of normal lizards did not alter the absorptive Na+ flux, but did reverse the net absorption of Cl- to become net secretion. Cl- secretion resulted from an increase in its serosal-to-mucosal movement and was positively correlated to an increase in short-circuit current. Ba2+-induced short-circuit current was dependent on the presence of both Na+ a...

Inward rectifier K+ channels (Kirs) were studied in the isolated perfused rat middle cerebral artery (MCA). The addition of 15 mM K+ (KCl) to the extraluminal bath dilated the MCAs. These dilations were blocked by selective inhibitors for the Kirs (40 μM BaCl2 or 40 mM CsCl) but not selective inhibitors for other K+channels (glibenclamide, tetraethylammonium, or 4-aminopyridine). Neither remova...

Studies were made in an effort to detect enhanced vasoconstriction ipsilateral to a ligated common carotid artery. No effect of ligation was found on the response to topically administered serotonin, norepinephrine or prostaglandin F2 alpha, in the gerbil in spite of varying a number of parameters, including anesthesia, percent of inspired oxygen, time elapsed following ligation, or body temper...

BACKGROUND Increasing extracellular K+ concentration within and just above the physiological range hyperpolarizes and relaxes vascular smooth muscle in vitro. These actions involve inwardly rectifying potassium channels (K(IR)) and Na+/K+ ATPase, which are inhibited, respectively, by Ba2+ and ouabain. The role (if any) of K(IR) in controlling human resistance vessel tone is unknown, and we inve...