Posted by Bennie (184.108.40.206) on January 23, 2000 at 11:42:50:
An article on Raynaud's phenomenon, where fingers and toes appear bloodless when exposed to cold, says the condition is caused by a loss of CGRP-containing nerve fibres resulting in a lack of vasodilation in the fingers, etc.
This CGRP (calcitonin-gene-related peptide) is "a powerful vasodilator, a 37 aminoacid peptide found widely in the central nervous system." It is present in "beaded fibres around blood vessels including the cerebral, mesenteric, and skin vasculature.The peptide circulates in human plasma and acts on receptors on the blood vessels to cause vasodilation."*
An article by Dr. Goadsby, mentioned in a previous post, reports that the level of CGRP in the blood of patients during a CH attack is 2.5 times normal.
This makes me wonder if perhaps we CHer's have too many of these nerve fibres in our heads which produce too much CGRP and thus cause acute attacks. Just a thought. It might not matter anyway, but I find it interesting to speculate.
Also mentioned in the Goadsby article was VIP, a peptide that is 3 times its normal level during a CH attack. This VIP is supposed to be the one which causes tearing, stuffiness, etc.
Later in the Raynaud's phenomenon article there is a mention of Capsaicin. Applied topically to fingers it causes a "release and depletion of neuropeptides and hence a functional impairment of the capacity of the afferent neurons" to release neuropeptides..."upon subsequent challenge." (Could that be the reason hot pepper sauce eases CH at least temporarily?)
Again, just speculating. Bennie
* "Raynaud's phenomenon" in The Lancet, July 29, 1995, v346,n8970,p283(8).
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