In isolated blood vessels, acetylcholine releases endothelium-derived relaxing factor (EDRF). In vivo, the vasodilator action of acetylcholine may be mediated by EDRF, but prostacyclin or prejunctional inhibition of adrenergic neurotransmission may also be involved. Therefore, we investigated whether acetylcholine releases EDRF in humans in vivo and, if so, whether the response altered in essen...

In isolated blood vessels, acetylcholine releases endothelium-derived relaxing factor (EDRF). In vivo, the vasodilator action of acetylcholine may be mediated by EDRF, but prostacyclin or prejunctional inhibition of adrenergic neurotransmission may also be involved. Therefore, we investigated whether acetylcholine releases EDRF in humans in vivo and, if so, whether the response altered in essen...

Chronic venous insufficiency may cause stasis ulcers that significantly impact on the quality of life. Many methods have been described for preventing or treating these ulcers. However, stasis ulcers often recur as a result of continuing venous insufficiency. Here we report a 30-year-old male patient with chronic venous insufficiency. He was admitted to the hospital owing to recurrent stasis ul...

Despite extensive investigation, the biological mechanisms causing essential hypertension (EHT) remain unclear. To clarify the means by which hypotensive prostaglandins (Hypo-PGs, mainly PGE1 and PGE2) act in patients with EHT, the interaction between intravenously infused Hypo-PGs and pressor substances such as an adrenergic neurotransmitter, noradrenaline (NA) and angiotensin II (AII) was exa...

The effects of opioids on cigarette smoke-induced plasma exudation were investigated in vivo in the main bronchi of anesthetized guinea pigs, with Evans blue dye as a plasma marker. Acute inhalation of cigarette smoke increased plasma exudation by 216% above air control values. Morphine, 0.1-10 mg/kg but not 30 mg/kg, inhibited the exudation but had no significant effect on substance P-induced ...

The allosteric receptor-receptor interactions over the interfaces in heteroreceptor complexes have been explored and their biochemical, pharmacological and functional integrative implications in the Central Nervous System (CNS) described. GPCR interacting proteins participate in these complexes mainly through modulation of receptor-receptor interactions. Methodologies to study heteroreceptor co...

We evaluated the effects of N(omega)-nitro-L-arginine (L-NNA, a nitric oxide (NO) synthase inhibitor) and carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO, a NO scavenger) on NO-mediated relaxation and noradrenaline release from adrenergic nerve endings induced by electrical field stimulation in the rabbit urethra. Electrical field stimulation caused frequency-depend...

1. We have compared the binding properties of several hexocyclium and sila-hexocyclium derivatives to muscarinic M1 receptors (in rat brain, human neuroblastoma (NB-OK 1) cells and calf superior cervical ganglia), rat heart M2 receptors, rat pancreas M3 receptors and M4 receptors in rat striatum, with their functional antimuscarinic properties in rabbit vas deferens (M1/M4-like), guinea-pig atr...

Circulating epinephrine may facilitate neural release of norepinephrine both during and after periods of sympathoadrenal activation by stimulation of prejunctional beta-adrenergic receptors. The present study was undertaken to examine possible effects and aftereffects of epinephrine on the hemodynamic reactivity to mental stress. To this end, two strictly standardized mental stress tests were p...

It has been suggested that there is a link between epinephrine synthesis and the development of β2-adrenoceptor-mediated effects, but it remains to be determined whether this development is triggered by epinephrine. The aim of this study was to characterize β-adrenoceptor-mediated relaxation and facilitation of norepinephrine release in the aorta of phenylethanolamine-N-methyltransferase-knocko...