Evidence for cortical noradrenaline release in vivo

Comparison of two indices for forearm noradrenaline release in humans.

Although there is as yet no method which measures directly the neuronal release of noradrenaline in humans in vivo, the isotope dilution technique with [(3)H]noradrenaline has been applied to estimate forearm neuronal noradrenaline release into plasma. Two different equations have been developed for this purpose: one to estimate the spillover of noradrenaline into the venous effluent, and a mod...

Vascular free radical release. Ex vivo and in vivo evidence for a flow-dependent endothelial mechanism.

Mechanisms underlying production of vascular free radicals are unclear. We hypothesized that changes in blood flow might serve as a physiological stimulus for endothelial free radical release. Intact isolated aortas from 45 rabbits were perfused with the spin trap alpha-phenyl-N-tert-butylnitrone (PBN, 20 mmol/L) and formed radical adducts detected by electron paramagnetic resonance spectroscop...

Presynaptic NMDA receptors stimulate noradrenaline release in the cerebral cortex.

Previous investigations in our laboratory revealed that N-methyl-D-aspartate (NMDA) and L-glutamate stimulate [3H]noradrenaline release in rat brain cortex slices (Fink et al., 1989; G&hert and Fink, 1989). However, the exact location of the NMDA receptor involved remained unclear. Tetrodotoxin strongly reduced the stimulatory effect of NMDA but failed to completely abolish it. This finding wou...

Suprachiasmatic modulation of noradrenaline release in the ventrolateral preoptic nucleus.

As the major brain circadian pacemaker, the suprachiasmatic nucleus (SCN) is known to influence the timing of sleep and waking. We thus investigated here the effect of SCN stimulation on neurons of the ventrolateral preoptic nucleus (VLPO) thought to be involved in promoting sleep. Using an acute in vitro preparation of the rat anterior hypothalamus/preoptic area, we found that whereas single-p...

Noradrenaline release and metabolism in orthostatic (postural) hypotension.