Effects of sepsis on mast cells in rat dura mater: influence of L-NAME and VIP.

1. The influence of lipopolysaccharide (LPS)-induced sepsis on the various mast cell phenotypes of rat dura mater were examined both by immunohistochemical and biochemical methods. 2.

Long-term superior cervical sympathectomy induces mast cell hyperplasia and increases histamine and serotonin content in the rat dura mater.

Nerve fibres and mast cells are often described in close morphological and functional interactions in various organs such as the dura mater. The respective roles of mast cell activation and sympathetic impairment in cluster headache and migraine attacks have been repeatedly suggested. We have thus investigated the long-term effects of sympathectomy on mast cell morphology and content in the rat dura mater.

Plasma protein extravasation induced in the rat dura mater by stimulation of the parasympathetic sphenopalatine ganglion.

It has been proposed that migraine could result from a neurogenic inflammation of the dura mater. According to this theory, inflammation could be initiated by an axon reflex of nociceptive nerve fibers, but the trigger of this axon reflex remains poorly understood. Previous works have shown that parasympathetic agonists can activate mast cells and/or sensory C-fibers, inducing pain and inflammation.

NE inhibits cerebrovascular mast cell exocytosis induced by cholinergic and peptidergic agonists.

Autonomic and sensory nerves frequently contact mast cells contained in rabbit leptomeningeal arteries. We have previously shown that parasympathetic and peptidergic neurotransmitters can stimulate mast cell granule exocytosis and serotonin (5-HT) release. In the present study, we examined ex vivo the possible action of the main sympathetic neurotransmitter, norepinephrine (NE), on this exocytotic process.

Differential processes of vascular smooth muscle cell differentiation within elastic and muscular arteries of rats and rabbits: an immunofluorescence study of desmin and vimentin distribution.

Two main populations of smooth muscle cells exist in the arterial media of adult mammals with respect to expression of two intermediate filament proteins: vimentin-positive/desmin-negative cells (V+/D-) and vimentin-positive/desmin-positive ones (V+/D+). However, it is still not understood how this phenotypic diversity is established. Since the proportion and the distribution patterns of the two muscle cell populations depend both on the type of blood vessel and the species examined, the aim of the present study was to determine and to compare their developmental origin in various artery segments from two different species.