Endogenous vasoactive substances and oxygen-derived free radicals in pulpal haemodynamics.
An adequate blood supply to the dental pulp is essential to the health of the tooth. A recent concept is that repeated stimulation of sensitive teeth may induce pulpal changes; this could occur through induction of neurogenic inflammation and alteration of pulpal blood flow. One possibility is that production of oxygen-derived free radicals at sites of inflammation contributes to alterations in local blood flow. The first target of free radicals, generated in several pathological processes, is the vascular system (essentially the endothelium). Although the exact mechanism by which free radicals induce changes in vascular conductance is still uncertain, they may act directly on vascular smooth muscle or modify vascular tone by interacting with the production and/or biological activity of endogenous vasoactive mediators. Recent data indicate that the oxygen-derived, free radical-generating system can decrease pulpal blood flow in the dog via endothelial dysfunction when applied locally in deep dentinal cavities. In addition to the part played by oxygen-derived free radicals, the measurement of pulpal blood flow and the effects of endogenous vasoactive substances on flow are discussed.
Okabe
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Department of Pharmacology, Kanagawa Dental College, Japan.
D000818:Animals; D003782:Dental Pulp / Q000098:blood supply*; D005609:Free Radicals / Q000009:adverse effects; D006801:Humans; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology; D018377:Neurotransmitter Agents / Q000494:pharmacology / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology; D011671:Pulpitis / Q000503:physiopathology; D017382:Reactive Oxygen Species / Q000009:adverse effects*; D012039:Regional Blood Flow; D014661:Vasoconstriction / Q000502:physiology*; D014666:Vasomotor System / Q000187:drug effects / Q000502:physiology
D005609:Free Radicals; D018377:Neurotransmitter Agents; D017382:Reactive Oxygen Species; D009569:Nitric Oxide