Functional Analysis of the Vasomotor Innervation of the Dog's Hind Footpad

Randall, Walter C.; Alexander, William F.; Cox, J. W.; Hertzman, Alrick B.

doi:10.1161/01.res.1.1.16

Cited by 11 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The data presented here are in accord with an earlier study by Randall and associates (4) in that vasoconstrictor responses were obtained from stimulation of the lumbar sympathetic chain as far caudal as the sacral level. A difference, however, is that in the present study the preganghonic inflow to the lumbar sympathetic trunk of vasoconstrictor fibers terminated at L-4, L-5, whereas these authors indicated inflows as far caudal as L-7.…”

Section: Donald Fergusonsupporting

confidence: 90%

Study of the Sympathetic Vasoconstrictor Nerves to the Vessels of the Dog Hind Limb

Donald

Ferguson

1970

Circulation Research

View full text Add to dashboard Cite

With a single exception, the responses to electric stimulation of the anterior spinal nerve roots, lumbar chain, or sympathetic ganglia were confined to the vessels of the ipsilateral limb. In 22 dogs with unilateral sympathectomy (L-2 through L-7), changes in hind-limb vascular resistance were induced reflexly or by electric stimulation of the anterior spinal roots. The results indicated that sympathetic control of the resistance vessels of the hind limb was still absent 77 days after sympathectomy. I. FUNCTIONAL ANALYSIS OF THE ROUTES TAKEN BY SYMPATHETIC VASOCON-STRICTOR NERVES FROM THE SPINAL CORD TO THE HIND LIMB VESSELS OF THE DOG• To investigate sympathetic nervous control of vascular resistance in actively contracting skeletal muscle in the dog, it is necessary to interrupt the sympathetic nerves to the vessels of the hind limb in a manner that permits study of the conscious exercising animal shortly after the vascular denervation. Essential to such a technique is a knowledge of the pathways taken by the sympathetic vasomotor fibers from the spinal cord to the hind limbs, particularly where they enter and leave the lumbar sympathetic chain. This information is also necessary to assess the degree to which the sympathectomy has interrupted neuro- This investigation was supported in part by U. S. Public Health Service Research Grant HE-6143 from the National Heart Institute.Received May 20, 1969. Accepted for publication December 1, 1969. genie control of the peripheral vasculature. The precise information needed was not available in previous studies (1-5). Methods IStudies were conducted in 22 dogs in which anesthesia was induced by sodium thiopental, 20 nig/kg, and a-chloralose, 60 mg/kg, and maintained by a-chloralose, 10 mg/kg/hour. Atropine was given in an initial dose, of 0.2 mg/kg and repeated at intervals of 1 hour. Heparin was given in an initial dose of 3 mg/kg and at hourly intervals in a dose of 1.5 mg/kg. Gallamine triethiodide (Flaxedil) was given in a dose of 50 mg at intervals of 1 hour to prevent muscle movement. These drugs were given intravenously. The animals were artificially ventilated with oxygen at a rate of 15 cpm and a peak inspiratory pressure of 12 cm H 2 O.Exit of Vasoconstrictor Fiber from the Spinal Cord.-The spinal cord was exposed from the T-9 through the L-7 level. At each segmental level, the anterior spinal nerve roots were isolated and the intervening spinal cord was removed. The femoral arteries were exposed bilaterally and

show abstract

Section: Donald Fergusonsupporting

confidence: 90%

Study of the Sympathetic Vasoconstrictor Nerves to the Vessels of the Dog Hind Limb

Donald

Ferguson

1970

Circulation Research

View full text Add to dashboard Cite

show abstract

“…The former authors suggested that the decrease in trunk skin temperature could be explained by vasoconstriction of trunk skin vessels above, and potentially also within, the analgesic areas [16]. This is an attractive hypothesis because the sympathetic system seems to be poorly organized, with sympathetic efferents overlapping several dermatomes [26][27][28], and blood flow to the upper extremity has been reported to decrease during both extradural and spinal anaesthesia with a T4 sensory level [4,6,8] possibly as a result of baroreflex activation by the accompanying decrease in arterial pressure.…”

Section: Interpretation Of Resultsmentioning

confidence: 99%

Regional Skin Temperatures Associated With Total Sympathetic Blockade in Conscious Dogs

Breuksch

Kousoulis

Krossa

et al. 1988

British Journal of Anaesthesia

View full text Add to dashboard Cite

Multiple regional skin temperatures were measured continuously before and after complete sympathetic nerve block by extradural anaesthesia in conscious dogs in environmental temperatures slightly below (22.4 (SEM 0.4) degrees C) and slightly above (27.2 (0.4) degrees C) the thermoneutral range. In the cold environment, skin temperature increased in the distal (+2.13 degrees C, P less than 0.001) and proximal (+1.1 degrees C, P less than 0.02) front limbs and distal (+3.25 degrees C, P less than 0.001) and proximal (+1.72 degrees C, P less than 0.001) hind limbs, but decreased on the chest (-0.83 degrees C, P less than 0.01) and abdomen (-0.67 degrees C, P less than 0.002). Similar changes (all significant) were seen in the warm environment, although the effects were smaller. Rectal temperature did not change during the experiments. Arterial pressure decreased in both groups after denervation, but was the same in the denervated state regardless of ambient temperature. Our results are incompatible with increased sympathetic discharge from unblocked regions being a dominant factor in the decrease in trunk skin temperature above and within the analgesic areas, and demonstrate a substantial contribution of the sympathetic nervous system to the maintenance of the normal skin temperature gradient along the long axis of the body.

show abstract

“…Preganglionic sympathetic fibres ascend and descend in the paravertebral sympathetic chain before synapsing with postganglionic neurones both above and below their segmental points of origin [2,20,21]. Those supplying the hind limbs could have emerged from the spinal cord at a much higher level than the sensory nerves of the lower extremity enter it, resulting in segmental analgesia restricted to only the upper thorax, but also in widespread sympathetic block involving the hind limbs with high thoracic extradural injection.…”

Section: Discussionmentioning

confidence: 99%

Effects of Segmental Thoracic Extradural Analgesia on Sympathetic Block in Conscious Dogs

Kousoulis¹,

Arndt²

1989

British Journal of Anaesthesia

View full text Add to dashboard Cite

To test the hypothesis that segmental thoracic extradural block causes sympathetic denervation caudally beyond dermatomes rendered analgesic, we have measured regional skin temperatures in six conscious dogs after upper thoracic, mid thoracic, and lumbar extradural injection of 0.5% bupivacaine 0.5, 1 and 2 ml cumulatively (total dose: 3.5 ml) given at 45-min intervals. Dogs were studied at constant ambient and rectal temperatures. Upper thoracic extradural injections resulted in a significant increase in skin temperatures on both the front (+1.4 (SEM 0.2) degrees C) and hind paw (+1.4 (0.3) degrees C), while the area of analgesia was confined to the upper trunk. With lumbar extradural injection, skin temperatures increased significantly (+2.0 (0.5) degrees C) on the lower extremities only. Mid thoracic injection significantly increased both front (+2.4 (0.9) degrees C) and hind paw (+2.2 (0.6) degrees C) skin temperatures, but decreased temperatures on the thorax (-0.9 (0.2) degrees C) and abdomen (-1.0 (0.2) degrees C), reversing the normal temperature gradient along the body axis. Irrespective of the injection site, skin temperatures on the trunk failed to increase or even decreased significantly. These data suggest that small doses of local anaesthetics applied to the extradural space of conscious dogs cause increased lower extremity skin temperatures caudal to areas unresponsive to pinprick stimulation when injected at a high thoracic level, and decreased trunk skin temperature even in analgesic areas, so that skin temperature measurements are unlikely to reflect purely sympathetic efferent activity on the trunk. Upper thoracic segmental extradural analgesia induced a decrease in sympathetic tone distal to the area of analgesia.

show abstract

Functional Analysis of the Vasomotor Innervation of the Dog's Hind Footpad

Cited by 11 publications

References 0 publications

Study of the Sympathetic Vasoconstrictor Nerves to the Vessels of the Dog Hind Limb

Study of the Sympathetic Vasoconstrictor Nerves to the Vessels of the Dog Hind Limb

Regional Skin Temperatures Associated With Total Sympathetic Blockade in Conscious Dogs

Effects of Segmental Thoracic Extradural Analgesia on Sympathetic Block in Conscious Dogs

Contact Info

Product

Resources

About