Biomedical subjects

M Schieppati

Publications and source records attributed to M Schieppati.

At least 37 records · Page 2Linked to original sources

PubMed1998

Medium-latency response to muscle stretch in human lower limb: estimation of conduction velocity of group II fibres and central delay.

In standing subjects, ankle dorsiflexion evoked short-latency responses (SLRs) at 41 and 57 ms, on the average, in soleus (Sol) and flexor digitorum brevis (FDB), respectively. Medium-latency responses (MLRs) occurred at 70 and 95 ms. The time between the MLRs was 25 ms and between the SLRs was 16 ms. The difference between these two values represents the extra-time to conduct the FDB volley for MLR from distal to proximal muscle, in excess to that for SLR. The velocity of the afferents mediating the FDB MLR (21.4 m/s on average) was estimated by dividing the distance between the two muscles by the sum of the above extra-time and the conduction time of Ia fibres along the same distance. The central delay of FDB MLR (6.7 ms on average) was obtained by dividing the distance between FDB and spinal cord by the sum of afferent and efferent MLR conduction times. The central delay of FDB SLR (1.4 ms) was analogously obtained. These findings give an estimation of the conduction velocity of the group II afferent fibres in humans and support the hypothesis that the FDB MLR is relayed through a spinal oligosynaptic pathway.

Adult↗

PubMed1998

Time course of stabilometric changes after a strenuous treadmill exercise.

OBJECTIVE: To detect the effect of a strenuous exercise on equilibrium and to quantify its time course. PARTICIPANTS AND METHODS: Body sway area, sway path, and center of foot pressure were recorded in eight young able-bodied subjects, standing quietly with feet together, with eyes open (EO) and eyes closed (EC), on a dynamometric platform, before and after treadmill walking for 25min, during which subjects approached the maximum heart rate. RESULTS: A significant increase in body sway was observed after exercise. It was present under both visual conditions and affected both sway area and sway path. Sway increased most in the initial few minutes (sway area EO=800.7mm2 [p < .005], EC=1,779.5mm2 [not significant]; sway path EO=545mm [p < .0001], EC=811.8mm [p < .05]) with respect to preexercise values (sway area EO=449.4mm2, EC=1,316.2mm2; sway path EO=369.5 mm, EC=652.5mm) and was followed by a plateau (sway area EO=609.9mm2, EC=1,567.9mm2; sway path EO=431.2mm, EC=710.9mm). Full recovery to basal values occurred within about 15min after the end of the exercise. CONCLUSIONS: Body sway is affected by prolonged fatiguing exercise, such as strenuous walking. This effect is of moderate extent and vanishes within a few minutes.

Adult↗

PubMed1997

Medium-latency stretch reflexes of foot and leg muscles analysed by cooling the lower limb in standing humans.

1. In standing subjects, an ankle-dorsiflexing perturbation of the supporting surface evokes a short-latency response (SLR) and a medium-latency response (MLR) to stretch in both soleus (Sol) and flexor digitorum brevis (FDB) muscles. The SLR is the counterpart of the monosynaptic reflex, whilst the MLR might be either mediated by Ia fibres, the delay being due to a long-loop central circuit, or by fibres of slower conduction velocity. Since small afferents are slowed more than large ones by low temperature, a greater latency increment for the MLR than the SLR induced by cooling of the limb would point to a peripheral origin of the MLR. 2. In nine subjects, one limb was cooled by circulating water in a tube wrapped around it for about 120 min. Perturbations were delivered to the same limb prior to and during cooling, and after rewarming. EMG was recorded by surface electrodes from the Sol and FDB muscles. 3. The mean increase in latency of MLRs was significantly greater than that of SLRs in both muscles. On average, the Sol SLR increased from 42.4 to 47.0 ms and the Sol MLR from 72.0 to 82.3 ms. The FDB SLR increased from 58.1 to 66.5 ms and the FDB MLR from 94.9 to 110.5 ms. The mean difference (MLR minus SLR) increased from 29.6 to 35.2 ms for Sol, and from 36.8 to 43.9 ms for FDB at the end of cooling. After 30 min of rewarming, the responses of both muscles recovered towards control values. 4. The greater latency increment of the MLRs than of the SLRs favours the hypothesis of a slower conduction velocity of the responsible afferent fibres. The most likely candidate fibres are the spindle group II afferents.

Adult↗

PubMed1997

Intracortical inhibition and facilitation are abnormal in Huntington's disease: a paired magnetic stimulation study.

Transcranial magnetic stimulation with a conditioning-test paradigm was used to assess cortico-cortical interactions in the motor cortex of 11 patients with Huntington's disease (HD) as compared to normal controls (NC). In the HD patients, threshold and amplitude of motor potentials evoked in the opponens pollicis muscle at rest were not significantly different from NC. The cortico-cortical inhibition at interstimulus intervals of 2-5 ms was significantly reduced and the cortico-cortical facilitation at longer intervals (10-25 ms) was significantly enhanced. Changes of intracortical inhibition and facilitation were related to clinical rating of choreic dyskinesias. The data support the hypothesis of a functional impairment of the motor cortex-basal ganglia loop in HD patients.

Adult↗

PubMed1997

Human stance stability improves with the repetition of the task: effect of foot position and visual condition.

The effects of repetition of quiet stance trials on body sway, recorded through a stabilometric platform, were studied in 12 normal subjects. With feet together, both with eyes open (EO) and closed (EC), a progressive shift forward of the centre of foot pressure (CFP) occurred with repetition. In addition, with EC, but not with EO, a significant progressive reduction in sway area (SA) and sway path (SP) occurred. With feet 10 cm apart, initial SA and SP values were significantly smaller than with feet together, regardless of the visual condition, but repetition of trials induced no significant effects on either position of CFP or body sway under either visual condition. Results indicate the occurrence of a learning phenomenon in this simple postural task, whereby the body shifts towards a 'safer' position with a minimum energy expenditure due to reduced corrections of sway. Forward leaning and decrease in sway are two independently-occurring processes, each possibly due to a better central integration of proprioceptive input with repetition of trials.

Adolescent↗

PubMed1997

Fatigue effects on body balance.

Body sway variables (sway area and sway path) were recorded by a dynamometric platform in 13 young subjects, standing quiet with feet together, with eyes open (EO) and eyes closed (EC), prior to and following two types of physical exercise (treadmill walking and cycle ergometer pedalling). Each exercise was performed under both fatiguing (above anaerobic threshold) and non-fatiguing conditions. Following fatiguing treadmill exercise, we observed a significant increase in body sway with respect to pre-exercise values. The increase was present under both visual conditions, affected both sway area and sway path and lasted until about 15 min from the end of the exercise. The Romberg quotient (the ratio of EC/EO of sway area, or sway path) significantly increased after the fatiguing exercise with respect to the non-fatiguing exercise. The mean position of the centre of foot pressure (CFP) was unchanged after the exercise. Fatigue induced an increase in the median frequency of oscillation of the centre of foot pressure, independent of the amplitude of sway. Non-fatiguing treadmill exercise induced no significant changes in sway or in its frequency content. Following fatiguing cycle ergometer exercise, a negligible increase or a decrease (under eyes closed condition) in body sway were observed. Non-fatiguing cycling exercise induced no significant changes or a decrease in sway. Control experiments showed that simple repetition of successive stance trials (without intercalated exercise) was able by itself to induce a decrease in sway. By taking this effect into account, both types of cycling exercises revealed a mild capacity to increase sway. We concluded that body sway increased after strenuous physical exercise, but was little affected by exercise performed below the estimated anaerobic threshold. The effects of fatigue on sway were short-lasting and of moderate extent, and therefore were not liable to seriously threaten body equilibrium.

Adolescent↗

PubMed1996

Different effect of height on latency of leg and foot short- and medium- latency EMG responses to perturbation of stance in humans.

In standing humans, platform perturbations evoked short- (SLR) and medium-latency responses (MLR) in soleus (Sol), tibialis anterior (TA) and flexor digitorum brevis (FDB) muscles. The latency of all responses significantly increased with subjects' height. The slope of the regression lines for the MLRs versus height was significantly steeper than that for the SLRs. The conduction velocity of the afferent fibres mediating the FDB MLR, calculated on the basis of the regression, was 17.5 m/s. These findings indicate that the MLRs are transmitted through afferent fibres slower than those mediating the SLRs. While the latter fibres are spindle group Ia afferents, the former are suggested to be group II fibres.

Adolescent↗

PubMed1996

Selective facilitation of responses to cortical stimulation of proximal and distal arm muscles by precision tasks in man.

1. The responses of the first dorsal interosseus (1DI), opponens pollicis (OP), extensor digitorum communis (EDC), brachioradialis (BR), biceps brachii (BB) and anterior deltoid (AD) muscles to magnetic stimulation of the motor cortex were recorded during different motor tasks. 2. Two precision and two power isometric tasks were investigated. The precision tasks were a pincer grip ('grip') and a thrust against a target with the wrist ('push'). In the former, the prime movers were the intrinsic hand muscles, while the proximal muscles played a postural role. In the latter, the prime movers were the proximal muscles. In both tasks, force was controlled through visual feedback. The power tasks required encirclement of a cylinder with the fingers ('grasp'), or sustaining a weight suspended at wrist level ('load'). 3. Magnetic stimulation was applied in eight subjects by a coil placed over the vertex at 1.1-1.2 times the motor threshold for the most excitable muscles. This produced in the prime mover muscles larger motor-evoked responses (MEPs) during grip or push tasks than grasp or load tasks, in spite of similar background EMG levels. During grip tasks, only one of the two prime movers showed task-dependent changes. In the postural muscle AD there was no significant difference between MEPs during grip and grasp tasks; however, BB responses were larger during grasp than grip tasks. 4. MEPs simultaneously recorded in the prime movers were plotted against each other. The slope of the regression line for AD versus BB was larger in push than load tasks, whilst the changes in MEPs of 1DI and OP were independent during both grip and grasp tasks. 5. In three subjects, MEPs were also elicited by electrical stimulation during grip and grasp tasks. MEP changes tended to parallel those obtained for magnetic stimulation, but the increase in size of the electrically evoked MEPs during the precision task was smaller. 6. In all subjects the median and ulnar nerves were stimulated during grip and grasp tasks, and an H reflex was evoked in the hand muscles of five subjects. In no case did the two tasks produce reflexes of different amplitude. 7. The motor response of both proximal and distal muscles can be task dependent, in spite of the differences in their principal functional role and cortical representation. The modulation is related to the degree of control requested by the task, and is likely to reflect selective changes in the excitability of corticospinal neurones.

Adult↗

PubMed1996

Muscle relaxation in Parkinson's disease: a reaction time study.

We tested the hypothesis that the relaxation reaction time in Parkinson's disease (PD) is delayed, as a sign of disorder in the control of voluntary motoneuron derecruitment. We compared, in the triceps brachii muscle, the reaction times (RTs) of the onset (O-RT) of electromyographic (EMG) activity during initiation of a contraction with the RTs of the termination of EMG tonic activity during full relaxation (R-RTs). Fourteen patients with idiopathic PD and 10 normal controls were examined. Mean R-RTs for all controls were 30 ms shorter than mean O-RTs. Mean R-RTs for all patients were approximately 70 ms longer than mean O-RTs. In two untreated patients levodopa therapy improved both O-RT and R-RT, but the difference between the two was unchanged. There was no correlation between EMG level and R-RT or between peak force and O-RT in either controls or patients. O-RT and R-RT were correlated with the bradykinesia score. In some patients, bursts of late activity were recorded after the R-RT; the duration of this activity was correlated with the duration and staging of the disease and with bradykinesia and rigidity scores. The reversed latency of onset and termination of muscle contraction in PD suggests an abnormality in the inhibitory spinal mechanisms, possibly stemming from a defect in the pathways descending to the spinal cord.

Aged↗

PubMed1996

Unilateral displacement of lower limb evokes bilateral EMG responses in leg and foot muscles in standing humans.

During upright stance, foot dorsiflexion induced by the movement of a supporting platform elicits a short- (SLR) and a medium-latency response (MLR) in both the soleus and the flexor digitorum brevis muscles; foot plantarflexion elicits a MLR in the tibialis anterior. The SLR is the counterpart of the stretch reflex, but no general agreement exists about the origin of the MLR, though recent results suggest that it is transmitted through group II afferent fibres. Animal studies have shown that group II fibres impinge on interneurones projecting contralaterally as well as ipsilaterally, whereas group I fibres impinge on interneurones which project mainly ipsilaterally. Therefore, we compared the changes in amplitude and latency of the SLRs and MLRs in the right and left limb during postural perturbations induced while subjects maintained both feet on the platform (both-on condition) or while they maintained only one foot on the platform and the other on firm ground (one-on condition). Under the both-on condition, the pattern of EMG responses described above occurred bilaterally. Under the one-on condition, both SLRs and MLRs occurred in the displaced leg. However, whereas the SLRs did not change in amplitude compared with the both-on condition, the MLRs decreased in amplitude to about 50%. MLRs were also present in the non-displaced leg. They were not preceded by any SLR but showed a further decrease in size with respect to the corresponding responses in the perturbed leg. Latency of the MLRs of the perturbed leg increased by about 5 ms passing from the both-on to the one-on condition. In the latter condition, a further increase of 5 ms was observed in the nonperturbed leg with respect to the displaced one. The occurrence of the MLRs but not of the SLRs in the contralateral non-displaced leg is in keeping with the notion that crossed neural pathways fed by spindle group II afferent fibres subserve the MLRs. The changes in latency of the MLRs under the one-on condition compared with both-on give a cue about the synaptic delays along the neural circuit and the time taken by the afferent impulses to cross the spinal cord.

Adult↗

PubMed1996

The excitability of the human motor cortex increases during execution and mental imagination of sequential but not repetitive finger movements.

Motor potentials (MEPs) evoked by focal (figure-of-eight coil) transcranial magnetic stimulation of the left motor cortex were recorded from the right opponens pollicis (OP) and flexor digitorum superficialis (FDS) of 14 normal subjects during different motor tasks. Changes in motor cortical excitability under behavioural conditions presumably connected with premotor and supplementary motor area (SMA) activation were investigated by comparing the size of the MEPs obtained during: (1) rest, (2) mental calculus, (3) repetitive left thumb-to-index opposition, (4) mental simulation of the same task with the right hand, (5) sequences of left thumb-to-fingers opposition, and (6) mental simulation of the same sequences with the right hand. MEP size significantly increased in both muscles during sequential movements of the left hand and sequence simulation with the right hand, but not during mental calculus or actual or simulated repetitive movements. The H-reflex evoked in the OP and FDS muscles by electrical stimulation of the median nerve (at wrist and elbow, respectively) under the same experimental conditions did not show significant modifications. The increase in MEP size during non-routine actual or imagined sequences of finger movements supports the view that the SMA is activated under these conditions and that it exerts a direct facilitatory influence on the motor cortex.

Adult↗

PubMed1996

Task-dependent effects evoked by foot muscle afferents on leg muscle activity in humans.

The effect of low intensity electrical stimulation of the posterior tibial nerve (PTN) at the ankle on the active triceps surae (TS) muscles was studied in normal subjects, both in a prone position and while standing. PTN stimulation regularly evoked the H-reflex in the flexor digitorum brevis and, in the prone position, a short-latency facilitatory effect in the soleus muscle. During standing, the facilitatory effect was preceded by a clear-cut reduction in electromyograph (EMG) activity. The inhibition-facilitation sequence was evoked in the gastrocnemii under both conditions, on average, though individual differences were present. An EMG modulation similar to that observed under standing conditions was present also in the prone position when subjects pressed the sole of the foot against the wall. Stimulation of sural or digital nerves did not evoke similar effects. It is concluded that foot muscle afferents establish oligosynaptic connections transmitting mixed effects to the TS motoneuronal pool, and that contact with the sole of the foot plays an enabling role for the inhibitory pathway directed to the soleus muscle.

Adult↗

PubMed1995

Time course of 'set'-related changes in muscle responses to stance perturbation in humans.

1. In standing subjects, toe-down rotation of a supporting platform elicits a medium-latency response (MLR) in tibialis anterior (TA) muscle and a long-latency response (LLR) in soleus (Sol). Toe-up rotation induces a short-latency response (SLR) in Sol and a LLR in TA. When subjects steadily hold onto a stable frame, all responses are decreased, except Sol SLR. The aim of this investigation was to assess whether the response modulation is dependent on information from the hand touching the frame, or whether it anticipates the holding task. 2. The time course of the changes in response amplitude was studied in a time interval centred around the act of holding, performed in a reaction-time mode. Subjects kept their extended arm close to the frame in front of them and brought the hand in contact with the frame in response to a visual go-signal. The platform was moved at different intervals prior to or after the go-signal. Surface EMGs of Sol, TA and deltoid (Delt) were recorded. 3. TA MLR began to decrease when the platform was displaced at an interval of 140 ms after the go-signal, about 200 ms before subjects touched the frame and 120 ms before termination of Delt EMG. Four hundred milliseconds after the go-signal the response reached and maintained maximal inhibition, similar to that occurring under the stationary holding condition. The time course of inhibition of Sol LLR and TA LLR was similar to that of TA MLR, except that LLRs began to decrease at an earlier interval. Due to the different response latency from the onset of the perturbations, the beginning of inhibition of both MLRs and LLRs occurred almost simultaneously. 4. The changes in amplitude of leg muscle responses are not triggered by the go-signal, contact with the frame, or arm motion, suggesting that the modulation is related to the transition to a new, stabilized postural 'set'. The similar extent and parallel time course of MLR and LLR suppression, possibly transmitted through different pathways, points to the spinal cord as the site of action. The lack of depression of the monosynaptic SLR suggests an effect at premotoneuronal level. On the basis of selectivity, latency and time course of the effect, we favour the hypothesis that a monoaminergic pathway from the brainstem is involved.

Adult↗

PubMed1995

Selective depression of medium-latency leg and foot muscle responses to stretch by an alpha 2-agonist in humans.

1. In standing humans, toe-up rotation of a platform induces a short-latency (SLR) and a medium-latency response (MLR) in both soleus (Sol) and flexor digitorum brevis (FDB) muscles. Toe-down rotation evokes a MLR in the tibialis anterior (TA). The SLR is the counterpart of the monosynaptic stretch reflex, but the origin of the MLR is still debated. By means of tizanidine (an alpha 2-adrenergic receptor agonist) we tested the hypothesis that the MLR is relayed by group II afferent fibres, since animal data indicate that tizanidine or stimulation of monoaminergic brainstem centres decrease the excitability of spinal interneurones supplied by those fibres. In addition, we compared the effect of the drug on these responses with that induced by stabilization of posture. 2. Eight subjects received tizanidine (150 micrograms kg-1 orally) or placebo, in a single-blind design. Platform rotations were delivered prior to administration and for 3 h afterwards. Both TA- and FDB-MLRs decreased in size, starting from about 1 h after tizanidine administration. Sol-SLR was unaffected. Response latencies were unchanged. Placebo induced no changes in any response. In each subject, the extent of TA-MLR depression induced by holding onto a frame and by tizanidine was superimposable. 3. The selective effect of tizanidine on MLR supports the notion that it is relayed through group II afferent fibres. The similar effects of holding and tizanidine on the response suggests that it is modulated by monoaminergic centres.

Adrenergic alpha-Agonists↗

PubMed1995

Early and late stretch responses of human foot muscles induced by perturbation of stance.

In eight subjects standing on a movable platform, surface EMG activity was recorded from the foot muscles extensor digitorum brevis (EDB) and flexor digitorum brevis (FDB) and from the leg muscles soleus (Sol) and tibialis anterior (TA) during perturbations of upright stance. Perturbations inducing foot dorsiflexion (upward tilt and backward translation) evoked a short-latency response (SLR) and a medium-latency response (MLR) to stretch in the physiological extensors FDB and Sol, and a long-latency response (LLR) in the physiological flexors EDB and TA. Perturbations inducing plantar-flexion (downward tilt and forward translation) evoked the MLR in EDB and TA, and the LLR in FDB and Sol. The latency of the FDB and Sol SLR was compared to that of the H and T reflexes evoked in the same muscles by electrical or mechanical stimulation, respectively. In both muscles, the T reflex and the SLR followed the H reflex at delays accounted for by the different stimulation mode, indicating that the SLR induced in both muscles by upward tilt and backward translation was a true autogenetic stretch reflex from spindle primaries. The time interval between the onset of SLR and of MLR was significantly greater for the FDB than the Sol muscle, suggesting that MLR is a spinal reflex travelling through slower peripheral afferent pathways than SLR. From these latency differences and from the distance between the muscles, we calculated in four subjects the conduction velocity of the afferent fibres presumably responsible for the MLR in FDB. This was about 29 m/s. LLRs were evoked in TA and EDB during upward tilt and backward translation, and in Sol and FDB during downward tilt, but not forward translation. LLRs did not adhere to a proximal-to-distal pattern, since these could appear earlier in the foot than in the leg muscles. All responses were modulated by perturbation type (tilt vs translation) and body posture (normal stance vs forward leaning). Both the large amplitude of the foot muscle responses and their temporal pattern indicate that the muscles acting on the toes play a major role in stabilising posture. Their action increases in amplitude and extends in time the foot-ground reaction force, thereby improving the efficiency of the superimposed action of the leg muscle responses.

Adult↗

PubMed1995

Influence of aging on leg muscle reflex responses to stance perturbation.

The effect of age on latency and amplitude of leg muscle responses to stance perturbations was studied in 75 control subjects. They stood upright on a platform and were displaced by toe-up (upward tilt) and toe-down (downward tilt) platform rotations. Perturbations were induced during free and supported stance (holding on to a stable structure). Surface electromyograms (EMG) of the soleus (Sol) and tibialis anterior (TA) were recorded and latency and area of responses were measured. Body sway variables during stance with open or closed eyes were also recorded. Upward tilt evoked a short-latency response (SLR) in Sol and a long-latency response (LLR) in TA. Downward tilt evoked a medium-latency response (MLR) in TA and a LLR in Sol. This pattern of EMG responses was similar in both young and elderly subjects, although there were some differences in latency and amplitude. There was a significant relationship between latency of all responses and age. Slope of the regression lines of TA LLR, TA MLR, and Sol LLR was steeper than that of Sol SLR. Area of Sol SLR was unrelated to age, but a positive trend was identified in the other responses, significant for TA LLR. Under supported-stance condition, amplitude of TA MLR, TA LLR, and Sol LLR was decreased to a similar extent in both young and elderly subjects. There was a weak relationship between age and most body sway variables. A significant relationship was found between most sway variables and latency of Sol SLR and LLR, chiefly with eyes closed. Neither TA MLR nor LLR were significantly correlated with sway variables, but a trend was present for TA MLR with eyes closed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Response of arm flexor muscles to magnetic and electrical brain stimulation during shortening and lengthening tasks in man.

1. The responses of the brachioradialis and biceps brachii muscles to non-invasive magnetic and electrical stimulation of the human motor cortex have been investigated during performance of different tasks. 2. Both muscles were simultaneously active during elbow flexor isometric torque, or forearm flexion lifting a weight (shortening contraction), or extension breaking the fall of the weight (lengthening contraction). The forearm extensor triceps brachii muscle was not engaged in any task. By using different weights, comparable levels of EMG activity were obtained in the same muscle across tasks. 3. Both magnetic (7 subjects) and electrical (3 subjects) brain stimulation (at about 1.5 times the motor threshold) produced larger responses during shortening, and smaller responses during lengthening, in the brachioradialis muscle with respect to isometric contractions, in spite of equal background EMG levels. Responses evoked in the biceps brachii by either stimulation mode were smaller during lengthening but not significantly enhanced during shortening. No consistent differences in the task-related modulation of the responses were present between electrical or magnetic stimulations. No significant changes in the evoked responses occurred during passive elbow flexion or extension. 4. In three subjects, the H reflex was evoked in the brachioradialis by stimulation of the radial nerve during performance of the same tasks. The pattern of task-related modulation of the reflex amplitude paralleled that obtained for brain stimulation. 5. The opposite modulation induced by the shortening and lengthening tasks both in magnetically and electrically evoked motor responses, and in the H reflex, suggests that task-related changes in excitability of the cortical neurones play a minor role.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Protective effects of glutathione on cisplatin neurotoxicity in rats.

PURPOSE: Different attempts have been made to minimize the neurotoxicity of cisplatin (DDP) and the use of "neuroprotective" drugs seems to be a promising strategy. In rats we compared the effects on the dorsal root ganglia neurons and peripheral nerves of the administration of DDP alone or in combination with glutathione (GSH), a putative "neuroprotective" drug. METHODS AND MATERIALS: Twenty-four Wistar rats were treated with DDP alone (2 mg/kg/week) or with the same dose of DDP plus GSH (300 mg/week) for nine cycles and they were compared to 12 untreated age-matched rats. All the animals underwent either neurophysiological examination of the tail nerve or pathologic examination of the dorsal root ganglia. Analytical determination of the platinum concentration in dorsal root ganglia was also performed. RESULTS: Morphologic and morphometric evaluations demonstrated a reduced incidence of pathologic changes in DDP plus GSH-treated rats with respect to DDP-treated ones. In agreement with the morphological findings, the platinum concentration in the dorsal root ganglia was lower and sensory nerve conduction velocity in the tail nerve less markedly decreased in the animals treated with DDP plus GSH with respect to those treated with DDP alone. CONCLUSION: We conclude that the administration of GSH is effective in reducing the neurotoxic effects of DDP, thus supporting the preliminary results obtained in clinical trials in humans.

Animals↗