Expression of capsaicin receptor immunoreactivity in human peripheral nervous sy

[Guest guest]

J Peripher Nerv Syst. 2006 Sep;11(3):262-271.

Expression of capsaicin receptor immunoreactivity in human peripheral

nervous system and in painful neuropathies.

Lauria G, Morbin M, Lombardi R, Capobianco R, Camozzi F, Pareyson D,

Manconi M, Geppetti P.

Neuromuscular Diseases; Neuropathology; and Biochemistry and Genetics

Units, National Neurological Institute 'Carlo Besta'; Department of

Neurology, S. Raffaele University Hospital and Scientific Institute,

Milan; and Department of Clinical Pharmacology, University of

Florence, Florence, Italy.

We describe the expression of the capsaicin receptor (TRPV1) in human

peripheral nervous system (PNS) and its changes in sural nerve and

skin nerve fibers of patients with painful neuropathy. Dorsal root

ganglion (DRG), root, and spinal cord autopsy specimens from subjects

without PNS diseases were immunoassayed with anti-TRPV1 antibodies.

Bright-field and confocal microscope studies using anti-TRPV1,

protein gene product 9.5 (PGP 9.5), and unique-beta-tubulin (TuJ1)

antibodies were performed in skin biopsies from 15 healthy subjects

and 10 painful neuropathies.

The density of intraepidermal nerve fiber (IENF) labeled by each

antibody was quantified. Sural nerve biopsies from three patients

with painful, one patient with nonpainful diabetic neuropathy, and

two patients with multifocal motor neuropathy used as controls were

immunoassayed with anti-TRPV1 antibodies and investigated by

immunoelectron microscopy. TRPV1 strongly labeled laminae I and II of

dorsal horns, most small-size and some medium-size DRG neurons, and

small-diameter axons of dorsal roots.

In sural nerve, TRPV1 was expressed within the cytoplasm of most

unmyelinated and some small myelinated axons, in the muscular lamina

of epineural vessels, and in the endothelium of endoneurial vessels.

The density of IENF labeled by TRPV1, PGP 9.5, and TuJ1 did not

differ. TRPV1 colocalized with TuJ1 in all IENF and dermal nerve

bundles. Painful neuropathies showed a diffuse loss of TRPV1-positive

axons both in the sural nerve and in the skin.

Our findings demonstrated that TRPV1 is normally expressed throughout

the nociceptive pathway of PNS and that TRPV1-positive peripheral

nerve fibers degenerate in painful neuropathies.

[Guest guest]

Hello Gretchen,

This sure is a mouthful! What I get from it, is that long term

application of capsaicin analgesics leads to deadening of the pain

receptors local to the area of application. Several years ago, a

physiatrist who gave me a very great ammount of help sugested I use

Capsasin Ointment regularly and it has been a very great help in

reducing back muscle spasm that produces brusing of the spinal cord.

It looks like his judgement has been validated!

EdM from NH

-- In , " gfijig " <fijiwigged@...> wrote:

>

> J Peripher Nerv Syst. 2006 Sep;11(3):262-271.

>

> Expression of capsaicin receptor immunoreactivity in human

peripheral

> nervous system and in painful neuropathies.

>

> Lauria G, Morbin M, Lombardi R, Capobianco R, Camozzi F, Pareyson

D,

> Manconi M, Geppetti P.

>

> Neuromuscular Diseases; Neuropathology; and Biochemistry and

Genetics

> Units, National Neurological Institute 'Carlo Besta'; Department of

> Neurology, S. Raffaele University Hospital and Scientific

Institute,

> Milan; and Department of Clinical Pharmacology, University of

> Florence, Florence, Italy.

>

> We describe the expression of the capsaicin receptor (TRPV1) in

human

> peripheral nervous system (PNS) and its changes in sural nerve and

> skin nerve fibers of patients with painful neuropathy. Dorsal root

> ganglion (DRG), root, and spinal cord autopsy specimens from

subjects

> without PNS diseases were immunoassayed with anti-TRPV1 antibodies.

> Bright-field and confocal microscope studies using anti-TRPV1,

> protein gene product 9.5 (PGP 9.5), and unique-beta-tubulin (TuJ1)

> antibodies were performed in skin biopsies from 15 healthy subjects

> and 10 painful neuropathies.

>

> The density of intraepidermal nerve fiber (IENF) labeled by each

> antibody was quantified. Sural nerve biopsies from three patients

> with painful, one patient with nonpainful diabetic neuropathy, and

> two patients with multifocal motor neuropathy used as controls were

> immunoassayed with anti-TRPV1 antibodies and investigated by

> immunoelectron microscopy. TRPV1 strongly labeled laminae I and II

of

> dorsal horns, most small-size and some medium-size DRG neurons, and

> small-diameter axons of dorsal roots.

>

> In sural nerve, TRPV1 was expressed within the cytoplasm of most

> unmyelinated and some small myelinated axons, in the muscular

lamina

> of epineural vessels, and in the endothelium of endoneurial

vessels.

> The density of IENF labeled by TRPV1, PGP 9.5, and TuJ1 did not

> differ. TRPV1 colocalized with TuJ1 in all IENF and dermal nerve

> bundles. Painful neuropathies showed a diffuse loss of TRPV1-

positive

> axons both in the sural nerve and in the skin.

>

> Our findings demonstrated that TRPV1 is normally expressed

throughout

> the nociceptive pathway of PNS and that TRPV1-positive peripheral

> nerve fibers degenerate in painful neuropathies.

>