Effects of phenol on nervous conduction

Nathan, P. W.; Sears, T. A.

doi:10.1113/jphysiol.1960.sp006405

Cited by 69 publications

(16 citation statements)

References 8 publications

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“…To minimize these possibilities we chose, therefore, to block neural conduction in the hilum by stripping the adventitia of the renal artery while exposing it to phenol for at least 20 min. Phenol is known to produce an irreversible blockage of nerve conduction if exposure of neural tissues to the agent is sufficiently prolonged (18). It rupted neural traffic completely or that those branches of the renal nerves not exposed to the phenol were few and/or of relatively minor importance.…”

Section: Resultsmentioning

confidence: 99%

Effects of acute unilateral renal denervation in the rat.

Bello‐Reuss¹,

Colindres²,

Pastoriza-Munoz³

et al. 1975

J. Clin. Invest.

215

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A B S T R A C T Studies were undertaken to characterize the renal responses to acute unilateral renal denervation and the mechanisms involved in these responses. Denervation was produced in anesthetized nondiuretic rats by application of phenol to the left renal artery. Studies were also performed in sham-denervated nondiuretic rats. Whole kidney and individual nephron studies were performed before and after denervation or sham denervation. Denervation increased urine volume from the left kidney to about twice its control value (P < 0.001) and increased urinary sodium excretion from 332 neq min' to 1,887 neq min' (P <0.001). Glomerular filtration rate (GFR) and renal plasma flow (RPF) remained unchanged in both kidneys after the procedure. The innervated right kidney showed no changes in urine volume or in sodium excretion. After denervation, late proximal ratio of tubular fluid inulin concentration to that of plasma [ (F/P) In] decreased from 2.23 to 1.50 (P < 0.001) while single nephron GFR remained unchanged. Absolute reabsorption decreased from 16.5 to 9.9 nl min' (P <0.001). (F/P) i ratios were also decreased in early distal (from 6.21 to 3.18, P <0.001) and late distal convolutions (from 16.41 to 8.33, P < 0.001) during the experimental period. (F/P) Na ratios remained unchanged in the early distal convolutions, but increased from 0.18 to 0.38 (P < 0.01) in late distal convolutions after denervation. Absolute Na reabsorption after denervation increased in the loop of Henle, distal convolution, and collecting ducts. Any changes in intrarenal hydrostatic pressures

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Section: Resultsmentioning

confidence: 99%

Effects of acute unilateral renal denervation in the rat.

Bello‐Reuss¹,

Colindres²,

Pastoriza-Munoz³

et al. 1975

J. Clin. Invest.

215

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“…All experiments were performed under the same conditions as those previously used for investigating the differential action of local anaesthetics; these methods were described in our previous papers (Nathan & Sears, 1960a, 1961. The experiments were performed on seventeen cats anaesthetized with Nembutal (Pentobarbitone, Abbott Laboratories; 35-40 mg/kg), given by intraperitoneal injection.…”

Section: Methodsmentioning

confidence: 99%

Differential nerve block by sodium‐free and sodium‐deficient solutions

Nathan¹,

Sears²

1962

The Journal of Physiology

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In the present paper the results of lowering the concentration of sodium ions in the external medium of myelinated and non-myelinated fibres of the cat's spinal roots are described. These experiments were conducted in a similar manner to those of our previous study (Nathan & Sears, 1961) on the effects of local anaesthetics. It has been found that with sodium-freg solutions the small fibres are blocked more rapidly than large fibres; thus there is a differential rate of blocking, and the results resemble those obtained with anaesthetic solutions in which the concentration is at least critical for all fibres present. With sodium-deficient solutions, absolute differential blocking has been obtained, there being critical concentrations of sodium that block conduction in the smaller fibres while allowing that of the larger fibres to continue; in this respect these results resemble those obtained with critical concentrations of local anaesthetics.In our previous paper we put forward the suggestion that absolute differential blocking is due to the safety factor of small myelinated fibres being lower than that of large myelinated fibres. According to Tasaki's (1953) measurements, using the bridge-insulator method on isolated single myelinated fibres of the toad, the safety factor, defined as the ratio of the nodal action current to the nodal rheobasic current, is between 5 and 7.This implies that if the nodal action current is experimentally reduced to between 15 and 20 % of its normal value, conduction will fail. It is evident that if small fibres have a lower safety factor than these large fibres, a lesser reduction in the nodal action current will cause conduction to fail in them. We have been unable to find any published figures for the safety factor of small fibres.A preliminary report of some of the results has been made to the Physiological Society (Nathan & Sears, 1960b); since that time, similar findings by Uehara (1958Uehara ( , 1960 METHODSAll experiments were performed under the same conditions as those previously used for investigating the differential action of local anaesthetics; these methods were described in our previous papers (Nathan & Sears, 1960a, 1961. The experiments were performed on seventeen cats anaesthetized with Nembutal (Pentobarbitone, Abbott Laboratories; 35-40 mg/kg), given by intraperitoneal injection.In brief, solutions deficient in sodium were applied to nerve roots in a Perspex chamber of internal diameter 8 mm and a cubic capacity of 1 ml. The recording was made from a stretch of nerve fibres bathed in a solution containing the normal amount of sodium, the effects of sodium-deficiency being confined to the length of the nerve fibres in the chamber. Control experiments showed that the reduction in amplitude of the compound action potential was not due to diffusion of sodium ions away from the nerve on the recording electrodes, but was due only to a reduction in the number of fibres conducting impulses through the chamber. Further, as a precautionary measure, Krebs-Henseleit soluti...

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“…Most of these methods yield a reversible block, e.g. by electrical polarization (for a survey of literature see Sassen & Zimmermann, 1973;Fukushima, Yahara & Kato, 1975), by cooling (see Douglas & Malcolm, 1955;Franz & Iggo, 1968), by local pressure and/or ischaemia (Gasser & Erlanger, 1929;Clark, Hughes & Gasser, 1935), by local anaesthetics (Gasser & Erlanger, 1929;Nathan & Sears, 1961;Heavner & De Jong, 1973), by hyper-or hypotonic solutions (Nathan & Sears, 1962;Jewett & King, 1971; King, Jewett & Sundberg, 1972), or by phenol (Nathan & Sears, 1960;Iggo & Walsh, 1960;Wood, 1978). These reversible blocks were in most cases preferential for the 0022 (A,8) fibres, with the exception of the local anaesthetics and phenol which blocked non-myelinated (C) fibres first.…”

Section: Introductionmentioning

confidence: 99%

Irreverisble differential block of A‐ and C‐fibres following local nerve heating in the cat.

Klumpp¹,

Zimmermann²

1980

The Journal of Physiology

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SUMMARY1. Local heating of a nerve was used to block conduction in the myelinated or A-fibres while preserving normal function in most of the non-myelinated or Cfibres. Compound action potentials of A-and C-fibres, and impulses in single Cfibres were recorded to measure the block.2. Most experiments were done on the posterior tibial nerve of the cat's hind limb. Conducted heat was applied in successive periods of about 2 min each to 15 mm of the exposed nerve..3. The range of temperatures used was between 45 and 52 'C. Below 46 0C no conduction block was obtained. With increasing temperature the cumulative time of heating required to produce a block in at least 99 % of A-fibres decreased from around 110 min at 46-5 'C to 10 min at 51 'C.4. In the posterior tibial nerve the C-fibre compound action potential was reduced to 0-66 of control (mean of twenty-two experiments) when the A-fibre action potential was less than 1 % of control. The corresponding value of this selectivity coefficient was 0-20 in seven superficial peroneal and sural nerves.5. Once a conduction block of A-fibres was reached the remaining C-fibres showed normal functioning, including conduction of repetitive impulses at up to 30 Hz evoked by electrical nerve and adequate skin stimulation. C-fibre conduction persisted for at least 33 h, but not longer than 3 days. 6. This pure C-fibre nerve might be useful for studying central nervous system effects of C-fibres.

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Effects of phenol on nervous conduction

Cited by 69 publications

References 8 publications

Effects of acute unilateral renal denervation in the rat.

Effects of acute unilateral renal denervation in the rat.

Differential nerve block by sodium‐free and sodium‐deficient solutions

Irreverisble differential block of A‐ and C‐fibres following local nerve heating in the cat.

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