Vasomotor Responses to Laryngeal Nerve Stimulation

Nonadrenergic innervation of the rat laryngeal vasculature

“…They reported no change in blood flow to the lamina propria but an almost 10-fold increase to the TA. These data tend to support the more global findings of Shin et al (1970). While the relative changes may be correct for the stimulation parameter used, it is likely that absolute flow measurements were unreliable.…”

“…Whether this would have altered blood flow to the structures examined (TA and vocal fold) is unclear. However, given the results of Shin et al (1970), Franco-Cereceda et al (1995), and the present study, it is likely that blood flow would have been altered in some manner.…”

“…It is of importance to know at which level this occurs since contraction of the feeding arteries would have a much more global effect than that of the terminal arterioles. Contradictory to the data of Shin et al (1970), Matsuo et al (1987), and Tomita et al (1988), using oxygen tension changes as an estimate of blood flow, reported "ischemic changes" in the lamina propria and vocal muscle following either painful stimuli to produce phonation or nerve stimulation. However, these studies were somewhat flawed.…”

“…In fact there have been relatively few quantitative studies on laryngeal blood flow (only one aging study in rat; Malmgren, 1992) and even fewer during phonation. Shin et al (1970) reported a 30% increase in "total" laryngeal veinous outflow with either vagal or recurrent laryngeal nerve stimulation and a 20% decrease when stimulation was applied to the superior laryngeal nerve. These increases were abolished following atropine treatment suggesting adrenergic mechanisms were involved.…”

Fluorescence Histochemical Studies on the Noradrenergic Innervation of the Canine Larynx

“…With regard to the regulation of the blood flow volume of the larynx, the sym pathetic nerve for vasoconstriction is consi dered to participate in regulating the caliber of the laryngeal blood vessels [Yagi et al, 1966;Shin et al, 1970] and the vascular glomeruli in the laryngeal mucosa [Koizumi, 1953]. Abundant fluorescent nerve fibers surrounding the blood vessels in the laryngeal muscles seem to be evidence for the existence of sympathetic innervation to regulate the blood flow volume of the larynx.…”