Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Capsaicin, which causes release of neuropeptides including substance P, has been shown to cause dose-related increases in cochlear blood flow (CBF). Since CBF regulation is altered in animal models with endolymphatic hydrops, this study was designed to examine the effect of hydrops on capsaicin-induced CBF changes. CBF responses to 0.01 and 0.001% capsaicin applied to the round window membrane were measured in normal and 12-week hydropic guinea pigs using laser Doppler flowmetry. With 0.01% capsaicin, CBF increased by only 13 +/- 7.8% in the hydropic ear, compared with 34% +/- 13% in the normal animal (p = 0.027). With 0.001% capsaicin, CBF increased by only 7.5 +/- 4.2% in the hydropic ear, compared with 28 +/- 16% in the normal ear (p < 0.001). These findings demonstrate a reduced responsiveness to capsaicin with endolymphatic hydrops and suggest that hydrops causes an alteration in the peptidergic sensory fibers of the inner ear or in the vascular smooth muscle or both. The results are consistent with previous reports of reduced vascular responsiveness in hydropic guinea pigs and provide further evidence for abnormal CBF regulation in hydrops.
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PMID:Effect of endolymphatic hydrops on capsaicin-evoked increase in cochlear blood flow. 874 96

Meniere's disease (MD) is a chronic condition affecting the inner ear whose precise etiology is currently unknown. We propose the hypothesis that MD is a migraine-related phenomenon which may have implications for future treatment options for both diseases. The association between MD and migraine is both an epidemiological and a mechanistic one, with up to 51% of individuals with MD experiencing migraine compared to 12% in the general population. The presence of endolymphatic hydrops in those with MD may be the factor that unites the two conditions, as hydropic inner ears have an impaired ability to maintain homeostasis. Migraine headaches are theorized to cause aura and symptoms via spreading cortical depression that ultimately results in substance P release, alterations in blood flow, and neurogenic inflammation. Chronically hydropic inner ears are less able to auto-regulate against the changes induced by active migraine attacks and may ultimately manifest as MD. This same vulnerability to derangements in homeostasis may also explain the common triggering factors of both MD attacks and migraine headaches, including stress, weather, and diet. Similarly, it may explain the efficacy of common treatments for both diseases: current migraine treatments such as anti-hypertensives and anti-convulsants have shown promise in managing MD. Though the etiology of both MD and migraine is likely multifactorial, further exploration of the association between the two conditions may illuminate how to best manage them in the future. MD is likely a manifestation of cochleovestibular migraine, which occurs as a result of migraine related changes in both the cochlea and vestibule.
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PMID:A hypothetical proposal for association between migraine and Meniere's disease. 3162 54