This study was undertaken to explore the spinal cord segments controlling the canine and human vas deferens and differentiation of the mammalian sympathetic pathways to the vas deferens. Thoracolumbar white communicating rami (WCR) were electrically stimulated in the dogs. Stimulation of the 1st, 2nd, 3rd, and 4th lumbar WCR elicited an elevation of intraluminal pressure of the vas deferens in ...

In 6 normotensive Wistar-Kyoto (WKY) and 6 spontaneously hypertensive rats (SHRs) anesthetized with urethane and chloralose, paralyzed, artificially ventilated, vagotomized with carotid sinus nerves bilaterally cut, somatosympathetic reflex discharges were recorded in cervical and renal nerves by stimulating group II and III cutaneous afferents in the sural nerve. Only a long-circuited, late su...

Recently, interest has grown in the firing patterns of individual or multiunit action potential firing patterns in human muscle sympathetic nerve recordings using microneurography. Little is known, however, about sympathetic fiber distribution in human lower limb nerves that will affect the multiunit recordings. Therefore, the purpose of this study was to examine the sympathetic fiber distribut...

The sympathetic nervous system is essential for the cardiovascular responses to stimulation of visceral afferents. It remains unclear how the reflex-evoked sympathetic output is distributed to different vascular beds to initiate the hemodynamic changes. In the present study, we examined changes in regional sympathetic nerve activity and blood flows in anesthetized cats. Cardiovascular reflexes ...

Plasma norepinephrine (NE) concentrations are a fallible index of sympathetic neural activity because circulating NE can be derived from sympathetic nerves, the adrenal medullas, or both and because of regional differences in sympathetic neural activity. We used isotope dilution measurements of systemic and forearm NE spillover rates (SNESO and FNESO, respectively) to study the sympathochromaff...

Increased Binding of Norepinephrine by Nerves to Cerebral Blood Vessels: Evidence from the Effects of Reserpine on Nerves to Cerebral and Extracerebral Blood Vessels • It has been proposed by others that adrenergic nerves to cerebral blood vessels bind norepinephrine more avidly than do nerves to vessels outside the brain. This suggestion is supported by the present data which show that in the ...

Increased Binding of Norepinephrine by Nerves to Cerebral Blood Vessels: Evidence from the Effects of Reserpine on Nerves to Cerebral and Extracerebral Blood Vessels • It has been proposed by others that adrenergic nerves to cerebral blood vessels bind norepinephrine more avidly than do nerves to vessels outside the brain. This suggestion is supported by the present data which show that in the ...

It has been generally held in the past that the innervation of the coronary vessels of the mammal is peculiar with respect to the systemic blood vessels in that the parasympathetics, the vagi, were considered to be coronary vasoconstrictors and the sympathetic nerves, primarily coronary vasodilators. The evidence for this comes largely from work reported by Wiggers (l), Anrep and Segall (Z), Ho...

A 54-year-old man complained of burning pain, warm skin and erythema in his extremities. A diagnosis of primary erythromelalgia was made. Microneurography was used to clarify the role of skin sympathetic nerve activity in the pathophysiology of primary erythromelalgia. The patient showed normal skin sympathetic nerve activity but no vasoconstriction response. Aspirin activated the skin sympathe...

It has long been proposed that the renin-angiotensin system exerts a stimulatory influence on the sympathetic nervous system, including augmentation of central sympathetic outflow and presynaptic facilitation of norepinephrine release from sympathetic nerves. We tested this proposition in 19 patients with essential hypertension, evaluating whether the angiotensin receptor blockers (ARBs) eprosa...