To initiate and maintain bursts (and plateau potentials) in the presence of serotonin, guinea pig trigeminal motoneurons utilize L-type Ca2+ and persistent Na+ inward currents. However, the intrinsic currents that contribute to burst termination and determine the duration of the interburst interval are unknown. Therefore we investigated the roles of outward currents, whose slow activation is co...

We examined the responses of newborn piglet pulmonary resistance arteries (PRAs) to 5,6-epoxyeicosatrienoic acid (5,6-EET), a cytochrome P-450 metabolite of arachidonic acid. In PRAs preconstricted with a thromboxane A(2) mimetic, 5,6-EET caused a concentration-dependent dilation. This dilation was partially inhibited by the combination of charybdotoxin (CTX) and apamin, inhibitors of large and...

This study was undertaken to investigate the vasodilatory effect of an aqueous extract of Elaeis guineensis Jacq (EGE) in the porcine coronary artery and elicit its possible mechanism(s) of action. Vascular effects of crude extract of dried and powdered leaves of Elaeis guineensis were evaluated on isolated coronary arteries on organ chambers. Determination of eNOS expression and the phosphoryl...

OBJECTIVE Epoxyeicosatrienoic acids (EETs) serve as endothelial-derived hyperpolarizing factors (EDHF), but may also affect vascular function by other mechanisms. We identified a novel interaction between EETs and endothelial NO release using soluble epoxide hydrolase (sEH) -/- and +/+ mice. METHODS AND RESULTS EDHF responses to acetylcholine in pressurized isolated mesenteric arteries were n...

The involvement of endothelium-derived hyperpolarizing factor (EDHF) in the protective effect of 17beta-estradiol was investigated on the phenylephrine-precontracted carotid artery from cholesterol fed rabbits. Animals were fed for 8 weeks as follows: control group, standard chow; (control+estradiol) group, standard chow+17beta-estradiol; standard chow+1% cholesterol, cholesterol group; or (cho...

The aim of the present study was to investigate the role of certain subtypes of K+ channels in nerve-evoked contractions of pulmonary artery in vitro. The lobar or segmental pulmonary arteries were dissected from dogs, cut into ring segments, and the contractile responses to electrical field stimulation (EFS) and noradrenaline were measured under isometric conditions. Addition of iberiotoxin, a...

Intracellular recordings from spontaneously spindling GABAergic neurons of the ferret perigeniculate nucleus in vitro revealed a fast afterhyperpolarization after each action potential, a medium-duration afterhyperpolarization after each low-threshold Ca2+ spike, and a slow afterhyperpolarization after the cessation of spindle waves. The slow afterhyperpolarization was associated with an increa...

We describe two patients with claw hand as a result of a bee sting. It is likely that this was caused by the apamin in the sting which has an effect on the upper limb, at the spinal cord and on the peripheral nerves. It is important to recognise that the claw hand is not owing to compartment syndrome. Both patients were treated conservatively with full resolution within 48 hours, without any la...

OBJECTIVE: The aim of this study was to investigate the effects of melatonin on spontaneous and oxytocin-induced contractility of pregnant and non-pregnant rat myometrium in vitro. DESIGN: Myometrial strips were removed from virgin or late pregnant (21 days gestation) Wistar rats following decapitation and placed in an organ bath containing Krebs’ solution at 37°C and pH 7.4, constantly bubbled...