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Sensory Innervation In Human Myxomatous Mitral Valves:
Author(s) -
Rodriguez E Rene,
Tan Carmela D,
Griffin Brian P
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a128-d
Subject(s) - neurotrophin , tropomyosin receptor kinase a , tropomyosin receptor kinase b , nerve growth factor , medicine , contractility , anatomy , low affinity nerve growth factor receptor , endocrinology , biology , receptor , neurotrophic factors , cardiology
The innervation of the human atrioventricular valves has been described showing an intricate network of nerve fibers that extend from the base to the free border of the leaflet. The role of these nerve fiber networks is said to be in aiding contractility of the valve. However cardiac myocytes are sparingly present at the interface of the atrium and fibrous annulus at the base of the valve, thus it is unlikely that they contribute in any significant manner to contractility of the leaflet. Normal (n=4) and myxomatous (n=4) human mitral valve leaflets were immunostained with antibodies to the following neurotrophic factors: nerve growth factor (NFG), brain derived neurotrophic factor (BDNF), neurotrophins 3 and 4 (NT3) and (NT4) and their receptors TrkA, TrkB and TrkC as well as vasoactive intestinal polypeptide (VIP). Quantitation of mRNA expression of these neurotrophins was performed by real time polymerase chain reaction (RT‐PCR). All valves showed expression of the neurotrophins BDNF, NT3 and NT4, the neurotrophin receptor TrkB and VIP by immunohistochemistry. Their distribution is located mainly in the valvular interstitial cells present in the spongiosa. To a lesser extent, they are also present in the fibrosa and the atrialis. The myxomatous valves show a much more prominent expression of these markers that the normal valves. RT‐PCR showed higher expression of NT3, TrkB, TrkA and VIP mRNA in the myxomatous valves. Conclusion: The expression of neurotrophins and their receptors in the mitral valves suggest that the innervation of the valve may be sensory rather than motor. The increased expression of these molecules in the myxomatous valves may indicate that there is a dysregulation of the sensory function of the myxomatous valves.