Search PubMed⌕ Search

Biomedical subjects

E Jankowska

Publications and source records attributed to E Jankowska.

At least 73 records · Page 4Linked to original sources
PubMed1994

Effects of monoamines on transmission from group II muscle afferents in sacral segments in the cat.

The effects of one 5-HT1A serotonin agonist (8-OH-DPAT) and of two alpha 2 noradrenaline agonists (tizanidine and B-HT 933) were tested on the transmission between group II muscle afferents and spinal neurons in the sacral segments of the spinal cord in the cat. These agonists have previously been found to depress transmission from group II muscle afferents either in the dorsal horn or in the intermediate zone of midlumbar segments, and this study addressed the question of whether their actions in the sacral segments are similarly selective. The drugs were applied ionophoretically and their effects were tested on field potentials evoked from group II muscle afferents. As judged by changes in the amplitude of the early components of these field potentials, the transmission is effectively depressed by the serotonin agonist (to 56 +/- 26% after 2 min of ionophoresis of 8-OH-DPAT) but not by the noradrenaline agonists (to 97 +/- 12% after 6 min of ionophoresis of B-HT 933 and to 95 +/- 17% after 6 min of ionophoresis of tizanidine). These data suggest that transmission from group II muscle spindle afferents in the sacral segments is under control of serotonin releasing neurons, as in the dorsal horn of midlumbar segments, but leave open the question of the similarities or differences in the mechanisms (pre- and/or postsynaptic) of this control.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Interneurones in pathways from group II muscle afferents in sacral segments of the feline spinal cord.

1. Properties of dorsal horn interneurones that process information from group II muscle afferents in the sacral segments of the spinal cord have been investigated in the cat using both intracellular and extracellular recording. 2. The interneurones were excited by group II muscle afferents and cutaneous afferents but not by group I muscle afferents. They were most effectively excited by group II afferents of the posterior biceps, semitendinosus, triceps surae and quadriceps muscle nerves and by cutaneous afferents running in the cutaneous femoris, pudendal and sural nerves. The earliest synaptic actions were evoked monosynaptically and were very tightly locked to the stimuli. 3. EPSPs evoked monosynaptically by group II muscle afferents and cutaneous afferents of the most effective nerves were often cut short by disynaptic IPSPs. As a consequence of this negative feedback the EPSPs gave rise to single or double spike potentials and only a minority of interneurones responded with repetitive discharges. However, the neurones that did respond repetitively did so at a very high frequency of discharges (0.8-1.2 ms intervals between the first 2-3 spikes). 4. Sacral dorsal horn group II interneurones do not appear to act directly upon motoneurones because: (i) these interneurones are located outside the area within which last order interneurones have previously been found and (ii) the latencies of PSPs evoked in motoneurones by stimulation of the posterior biceps and semitendinosus, cutaneous femoris and pudendal nerves (i.e. the main nerves providing input to sacral interneurones) are compatible with a tri- but not with a disynaptic coupling. Spatial facilitation of EPSPs and IPSPs following synchronous stimulation of group II and cutaneous afferents of these nerves shows, however, that sacral interneurones may induce excitation or inhibition of motoneurones via other interneurones. 5. Comparison of the properties of group II interneurones in the sacral segments with those of previously studied group II interneurones in the midlumbar segments leads to the conclusion that these two populations of neurones are specialized for the processing of information from different muscles and skin areas. In addition, equivalents of only one of the two subpopulations of midlumbar interneurones have been found at the level of the pudendal nucleus: neurones with input from group II but not from group I muscle afferents. Neurones integrating information from group I and II muscle afferents and in direct contact with motoneurones thus seem to be scarce in the sacral segments.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1994

Ascending tract neurones processing information from group II muscle afferents in sacral segments of the feline spinal cord.

1. Ascending tract neurones located in the dorsal horn of sacral segments of the spinal cord have been investigated by extracellular and intracellular recording in the anaesthetized cat. The aim was to determine whether information from group II afferents that terminate within the sacral segments is conveyed to supraspinal structures and which types of neurones are involved. 2. A considerable proportion of ascending tract neurones found in the dorsal horn in the same segments as the pudendal (Onuf's) motor nucleus were excited by group II muscle afferents. The great majority (93%) of these neurones had axons ascending in ipsilateral funiculi. Spinocervical tract neurones constituted the largest proportion (82%) of such neurones, while very few spinocerebellar tract and propriospinal neurones and no postsynaptic dorsal column neurones were found among them. 3. In addition to activation by group II muscle afferents all of the neurones were strongly excited by cutaneous afferents. The most potent excitation was evoked by afferents of the posterior biceps-semitendinosus and gastrocnemius muscle nerves and by afferents of the cutaneous femoris, sural and pudendal nerves. The latencies of intracellularly recorded excitatory potentials were indicative of a high incidence of monosynaptic coupling between the afferents and ascending tract neurones. 4. The highly effective monosynaptic excitation of spinocervical tract neurones in the sacral segments by group II afferents is in contrast to the weak disynaptically mediated actions of group II afferents on such neurones in the L6-L7 segments but comparable to the actions of group II afferents on ascending tract neurones in the midlumbar segments. 5. Both the patterns of peripheral input and the latencies of synaptic actions in ascending tract neurones were similar to those in interneurones at the same locations (accompanying report). Similar information is therefore likely to be processed by both categories of neurones. 6. The role of sacral spinocervical tract neurones as a system for transmitting information from group II muscle afferents to supraspinal centres and the potential contribution of this system to the perception of limb position are discussed.

Afferent Pathways↗
PubMed1994

New observations on input to spino-cervical tract neurons from muscle afferents.

Peripheral input to spino-cervical tract (SCT) neurons located in the L4 and L5 segments of the cat spinal cord was investigated using both extracellular and intracellular recording. The main aim was to find out whether midlumbar SCT neurons are excited monosynaptically not only by cutaneous afferents but also by group II muscle afferents, as in the sacral segments but apparently not in the caudal lumbar segments. Input from group II muscle afferents was found in 73% of investigated neurons; the latencies of excitation by group II afferents were compatible with a monosynaptic coupling between these afferents and 62% of neurons. The majority of the midlumbar SCT neurons were excited by group II afferents of the quadriceps and deep peroneal nerves. The predominant monosynaptic input from cutaneous afferents to the same neurons was from the saphenous nerve.

Animals↗
PubMed1994

Morphometric ultrastructural study of satellite cells of rats during postnatal development (1st and 30th day of life).

Ultrastructural morphometric analysis of satellite cells of the diaphragm from one and 30-day-old rats was performed. The nuclear and cytoplasmic components of the cells were evaluated. The results obtained indicate that the satellite cells of one-day-old female rats are in a state of low activity. In 30-day-old animals, on the contrary, the cells are excited and active. This may be connected with their intensive participation in the process of development of the diaphragm muscle.

Animals↗
PubMed1994

Multifocal central nervous system glioma--a case history.

A case history of the multifocal brain glioma in 13-year-old girl is reported. Numerous neoplasmatic foci were found using MRI within the vermis and cerebellar hemisphere and, later, also within the brain stem, cervical spinal cord and both brain hemispheres. Bioptical examination of the tumors revealed the structure of anaplastic astrocytoma with oligodendromatous component. The authors suggest that the foci may be considered as multiple metastases from the primary cerebellar astrocytoma and the neoplastic cells might have been transported within CNS through cerebrospinal fluid.

Cerebellar Neoplasms↗
PubMed1993

Morphology of interneurones in pathways from group II muscle afferents in sacral segments of the cat spinal cord.

The morphology of 12 sacral interneurones with peripheral input from group II muscle afferents was analyzed after intracellular injection of horseradish peroxidase (HRP). The neurones were located in Rexed's laminae III-V overlying the pudendal (Onuf's) motor nucleus. The interneurones had medium sized elongated somata and dendrites projecting radially. All of the interneurones were funicular neurones and fell into two categories depending on whether their axons ran within the dorsal part of the lateral funiculus (DLF; n = 7) or within the ventral funiculus, or the ventral part of the lateral funiculus (VF or VLF; n = 4). The latter were located more rostrally. Within the DLF similar proportions of stem axons and secondary axonal branches descended and ascended. Within the VF and VLF all of the axons ascended. Collaterals of axons running in the DLF arborized primarily within the dorsal horn and the intermediate zone; none were found to approach the motor nuclei. In contrast, collaterals of axons running in the VF/VLF arborized in both the intermediate zone and the ventral horn and passed close to the motor nuclei. We conclude that sacral interneurones with group II input are morphologically nonhomogenous and that only those located most rostrally might have direct actions upon motoneurones. Both the axonal projections and the input (from group II but not from group I muscle afferents and from skin afferents) of sacral interneurones indicate that they are homologous to dorsal horn group II interneurones in the midlumbar segments. They appear, however, to form part of more local neuronal networks than their midlumbar counterparts.

Afferent Pathways↗
PubMed1993

Effect of glutamate receptor antagonists on N-methyl-D-aspartate- and (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-induced convulsant effects in mice and rats.

Selected antagonists of N-methyl-D-aspartate (NMDA) and (S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists, acting through different recognition sites were studied in three in vivo experimental procedures: systemic administration of NMDA or AMPA to mice and 7-day-old rats or i.c.v. injection in adult rats. Antagonists were given i.p. before the agonists. Of the substances tested (+)-5-methyl-10,11- dihydro-5H-dibenzocyclohepten-5,10-imine maleate ((+)-MK-801, an uncompetitive NMDA receptor antagonist) and DL-(E)-2-amino-4-methyl-5- phosphono-3-pentanoic acid (CGP-37849, a competitive NMDA receptor antagonist) were the most potent and selective NMDA receptor antagonists, having ED50s below 1 mg/kg in all three tests. 1-Amino-3,5-dimethyladamantane (memantine, an uncompetitive NMDA receptor antagonist) was less potent and, additionally, inhibited AMPA-induced seizures in adult rats. Aminocyclopropane carboxylic acid--a partial agonist at the glycine site coupled to NMDA receptors (GlyB)--was a weak antagonist (ED50 > 150 mg/kg) in mice. Other partial GlyB receptor agonists, aminocyclobutane carboxylic acid, (+,R)-3-amino-1-hydroxy-2-pyrrolidine ((+,R)-HA-966) and d-cycloserine, and antagonists, 5,7-dinitroquinoxaline-2,3-dione (MNQX) and 5,7-dichlorokynurenic acid, were ineffective in mice after systemic administration. The last two agents however were active in adult rats when given i.c.v. Thus affinity, intrinsic activity (GlyB receptor partial agonists) and/or penetration into the brain (GlyB receptor antagonists) seem to be important factors in determining the effectiveness of these agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Interactions between pathways controlling posture and gait at the level of spinal interneurones in the cat.

The properties of three interneuronal populations controlling posture and locomotion are briefly reviewed. These are interneurones mediating reciprocal inhibition of antagonistic muscles and interneurones in pathways from secondary muscle spindle afferents to ipsilateral and contralateral motoneurones, respectively. It will be shown that these interneurones subserve a variety of movements, with functionally specialized subpopulations being selected under different conditions. Mechanisms for gating the activity of these neurones appear to be specific for each of them but to act in concert. Interneurones which are active during locomotion and postural reactions are distributed over many segments of the spinal cord and over several of Rexed's laminae, both in the intermediate zone and in the ventral horn (Berkinblit et al., 1978; Bayev et al., 1979; Schor et al., 1986; Yates et al., 1989). The location of neurones discharging during neck and labyrinthine reflexes is illustrated in Fig. 1A and B but indications that neurones with an even wider distribution contribute to locomotion, scratching and the related postural reactions have been provided by neuronal markers which preferentially label active neurones (WGA-HRP; see Noga et al., 1987) or neurones with active genetic transcription (c-fos; I. Barajon, personal communication; Dai et al., 1991). Such a wide distribution indicates a high degree of non-homogeneity, since neurones of different functional types are usually located in different laminae. It has been demonstrated that some of these neurones may be particularly important for setting up the rhythm of muscle contractions specific for different gaits or scratching, as part of their "pattern generators" (see, e.g., Grillner, 1981). Other neurones may be primarily involved in initiation of these movements or in postural adjustments combined with them. A considerable proportion of neurones mediating these movements are nevertheless likely to be used not in one particular type of movement but in a variety of movements, and contribute to postural reactions and locomotion as well as to various segmental reflexes and centrally initiated movements; they are likely to operate as last order (premotor) interneurones of several spinal pathways to motoneurones. One of the indications that this is the case is the overlap between the areas of location of interneurones active during postural reactions, locomotion, or scratching and the areas of location of premotor interneurones (Fig. 1C,D). The latter were labelled by loading motoneurones with WGA-HRP and by its subsequent retrograde transneuronal transport (see Harrison et al., 1986).(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1993

Gating of transmission to motoneurones by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

1. Neuronal systems activated by stimulation in the region of the locus coeruleus/subcoeruleus (LC/SC) and raphe nuclei have previously been shown to depress transmission from group II muscle afferents in regions of the midlumbar spinal segments in which premotor interneurones are located. The aim of the present investigation was to determine the extent to which such depression is paralleled by depression of the reflex actions of group II afferents on motoneurones. 2. The effects of short trains of conditioning electrical stimuli applied within the LC/SC and raphe nuclei were examined on postsynaptic potentials (PSPs) evoked by group I and group II muscle afferents in hindlimb motoneurones. The effects were examined over a wide range of conditioning-test intervals but particular emphasis was placed on the effects produced at long intervals (> 100 ms) since such effects are more likely to be mediated by the descending noradrenergic and serotonergic neurones of the LC/SC and raphe nuclei which are of slow conduction velocity. In addition, conditioning stimuli alone evoked PSPs in motoneurones (with latencies of 7-15 ms and a duration of 50-80 ms) and effects evoked at short conditioning-test intervals might therefore have been secondary to changes in motoneurone membrane properties. 3. At conditioning-test intervals between 100 and 350 ms synaptic actions of group II origin were strongly and consistently depressed. Both EPSPs and IPSPs were affected, two-thirds of those tested being reduced in amplitude by 50% or more. A similar depression was exerted on PSPs evoked from the quadriceps and deep peroneal nerves mediated predominantly by interneurones located in the midlumbar segments and on PSPs evoked from the hamstring and triceps surae nerves mediated by interneurones located in more caudal segments. It is thus concluded that neuronal systems activated by stimuli applied in the LC/SC and raphe nuclei are capable of gating transmission in all those interneuronal pathways which mediate the reflex actions of group II afferents on motoneurones in anaesthetized animals.

Animals↗
PubMed1993

Depolarization of group II muscle afferents by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

1. Electrical stimuli applied in the locus coeruleus/subcoeruleus (LC/SC) and raphe nuclei produce a profound depression of transmission in reflex pathways from group II muscle afferents. The present experiments were performed to determine whether presynaptic inhibitory mechanisms contribute to these effects. 2. Changes in the excitability of afferent terminals to electrical stimuli have been used as an indication of primary afferent depolarization (PAD) produced by conditioning stimuli applied within the LC/SC and raphe nuclei and, for comparison, in the nucleus ruber. Group II afferents originating from ankle flexor muscles and terminating in the midlumbar segments were used for testing. 3. Clear changes in excitability were observed in fourteen of nineteen group II fibres in which the effects of conditioning stimuli applied in the LC/SC were tested and in twelve of seventeen fibres in which the effects of stimuli applied within the raphe nuclei were tested. By comparison, only one of the twelve fibres tested with conditioning stimuli applied to the nucleus ruber was found to be influenced. These effects matched those of the same conditioning stimuli on field potentials evoked by group II afferents at the location at which the terminals of group II fibres were stimulated. 4. Stimuli applied in the LC/SC and in the raphe nuclei both produced a mean decrease in threshold stimulus current of 19%. These effects are comparable to those produced by the most effective volleys in peripheral afferent which, in the same fibres, produced a mean decrease in threshold stimulus current of 24%. 5. In all cases (twelve) in which the effects of stimuli applied in the LC/SC and raphe nuclei were tested on the same group II fibre, either both or neither were found to be effective. This strengthens previous indications that some populations of neurones might be activated by stimuli applied in each of these regions of the brain. 6. In contrast to group II afferents, group Ia afferents investigated in the same experiments were only exceptionally affected. Of seven fibres tested with stimuli applied in the LC/SC, six with stimuli applied in the raphe nuclei and seven with stimuli applied in the nucleus ruber, only one fibre showed any clear change in threshold and this was a single fibre which was similarly affected by stimuli in all three sites. 7. It is concluded that presynaptic inhibitory mechanisms contribute to the depression of transmission in spinal reflex pathways from group II muscle afferents produced by stimulation in the LC/SC and raphe nuclei.

Animals↗
PubMed1993

A relay for input from group II muscle afferents in sacral segments of the cat spinal cord.

1. A neuronal relay for input from group II afferents of hindlimb muscle nerves has been found in the previously little explored sacral segments of the cat spinal cord. 2. Electrical stimulation of group II muscle afferents of a number of nerves evoked negative potentials on the surface (cord dorsum potentials) and population postsynaptic potentials (field potentials) within the sacral segments. The largest potentials were evoked by stimulation of the posterior biceps-semitendinosus and triceps surae nerves which evoke much smaller potentials in other segments. Group II afferents of other nerves, notably those which have their main relay within the middle lumbar segments, were much less effective. 3. The sites at which cord dorsum and field potentials evoked by group II muscle afferents were recorded varied in relation to the external topography of the L7-S2 spinal segments but were consistent in their location relative to the pudendal motor nucleus (Onuf's nucleus). Potentials evoked by group II afferents of the posterior biceps and semitendinosus nerves peaked at a level corresponding to the rostral half of Onuf's nucleus and potentials evoked by afferents of the gastrocnemius nerves peaked just rostral to this nucleus. The largest field potentials (of 0.5-1.0 mV) were recorded within the dorsal horn. Field potentials in the intermediate zone were much smaller (< 0.3 mV) and were seen less frequently. 4. Evidence was obtained that the dorsal horn field potentials are to a great extent evoked monosynaptically by the fast conducting fraction of group II muscle afferents: (i) they were evoked at short latencies (2.4-2.7 ms from the stimulus; 1.3-1.7 ms from group I components of afferent volleys and 0.5-0.7 ms from group II components of these volleys), (ii) the conduction times of impulses in the fastest conducting fraction of group II afferents, between the sacral segments (where these impulses were induced by intraspinal stimuli) and the peripheral nerves, were only about 0.5 ms shorter than the latencies of field potentials recorded at the site of intraspinal stimulation and evoked by stimulation of the same peripheral nerves and, (iii) the field potentials followed repetitive stimuli without temporal facilitation. 5. Negative cord dorsum and field potentials were also evoked by small stretches of the semitendinosus and triceps surae muscles. Although they were smaller than potentials evoked by electrical stimulation of sensory fibres and appeared at longer latencies, their presence is consistent with a contribution of muscle spindle afferents to the actions of group II muscle afferents within the sacral segments.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1993

Primary afferent depolarization of myelinated fibres in the joint and interosseous nerves of the cat.

1. Changes in the excitability of the intraspinal terminals of fibres in the posterior knee joint and interosseous nerves were used as a measure of primary afferent depolarization (PAD) which is associated with presynaptic inhibition of transmission from afferent fibres. These were estimated from changes in the intensity of electrical stimuli required to activate the fibres in 50% of trials. In order to avoid the inclusion of group I muscle afferents which contaminate the joint and interosseal nerves, the analysis was restricted to fibres conducting at less than 75 m s-1 and/or displaying patterns of PAD which differed from those of group Ia and Ib muscle afferents in lower lumbar segments of anaesthetized cats. PAD was evoked by electrical stimulation of ipsilateral hindlimb nerves. 2. PAD of fibres in the posterior knee joint nerve was induced from group I (Ia and Ib) and group II muscle afferents and cutaneous afferents but not by stimulation of the joint or the interosseous nerves. The most effective stimuli were those applied to the superficial peroneal, sural, quadriceps and posterior biceps and semitendinosus nerves. 3. PAD of fibres in the interosseous nerve was also induced by stimulation of group I (Ia and Ib) and group II muscle afferents and cutaneous afferents and, in addition, by stimulation of joint and interosseous nerves. The most effective stimuli were those applied to the superficial peroneal, quadriceps, flexor digitorum longus and posterior biceps and semitendinosus nerves. 4. Individual fibres of the joint and the interosseous nerves were depolarized by only some of the conditioning stimuli. Even the most effective stimuli did not produce PAD in all of the fibres tested. Individual fibres of the joint and the interosseous nerves were depolarized by diverse combinations of afferents of different functional types and of different peripheral nerves. The differences in the sources of PAD were not associated with the conduction velocities and hence are unlikely to be related to differences in the receptor origin of the tested fibres. The diversity in the sources of PAD of individual fibres is interpreted as providing a high degree of differentiation in the control of transmission from receptors in joints and interosseal membranes.

Animals↗
PubMed1992

Transmission from group II muscle afferents is depressed by stimulation of locus coeruleus/subcoeruleus, Kölliker-Fuse and raphe nuclei in the cat.

The effects of brief trains of electrical stimuli applied within the locus coeruleus and subcoeruleus, the Kölliker-Fuse nucleus and the raphe magnus, obscurus and pallidus nuclei were tested on transmission from group I and group II muscle afferent fibres in mid-lumbar spinal segments of chloralose anaesthetized cats. Changes in the effectiveness of transmission from these afferents were assessed from changes in the size of monosynaptic extracellular field potentials evoked by them. The depression of group II field potentials occurred at conditioning-testing intervals of 20-400 ms, and was maximal at intervals of 40-100 ms and 30-60 ms for potentials recorded in the intermediate zone and dorsal horn, respectively. At intervals up to about 30 ms it was combined with the depression of group I components of the intermediate zone field potentials. However, at longer intervals the conditioning stimuli depressed group II components of these potentials as selectively as monoamines applied ionophoretically at the recording site (Bras et al., 1989a, 1990). Thus, only the late depressive actions are considered as being possibly mediated by impulses in descending noradrenergic and/or serotonergic fibres. No major differences were found in the relative degree of depression of transmission from group II afferents by stimulation of the locus coeruleus/subcoeruleus, Kölliker-Fuse or raphe nuclei, either in the dorsal horn or in the intermediate zone. Since field potentials at these locations are preferentially depressed by ionophoretic application of serotonin and noradrenaline (Bras et al., 1990), and since the locus coeruleus/subcoeruleus, Kölliker-Fuse and raphe nuclei are interconnected, the study leads to the conclusion that both noradrenergic and serotonergic descending pathways can be activated by stimuli applied within either of them. Selective depression of field potentials of group II origin was also evoked by stimulation at other sites, e.g. the periaqueductal grey and medullary reticular formation, when conditioning-testing intervals were sufficiently long. Such a depression is considered to be secondary to activation of neurones of the locus coeruleus/subcoeruleus, Kölliker-Fuse or raphe nuclei and attributed to the spread of current or transsynaptic activation of these neurones, or to stimulation of their axon collaterals outside the nuclei rather than to other descending medullo-spinal systems. The non-selective depression of field potentials evoked by group I and group II afferents at shorter conditioning-testing intervals is proposed to be due to actions of reticulo-spinal pathways.

Afferent Pathways↗
PubMed1992

The involvement of NMDA receptors in acute and chronic effects of ethanol.

Recent evidence indicates involvement of excitatory amino acid receptors sensitive to N-methyl-d-aspartate (NMDA) in the action of ethanol (EtOH). Pronounced inhibition of NMDA receptor function is seen in vitro with concentrations of EtOH corresponding to those present during alcohol intoxication in humans. The present study was devoted to investigate the role of NMDA receptors in the action of EtOH in rats. Acute experiments showed antagonism by EtOH of convulsions induced by intracerebroventricular injection of NMDA. A similar effect was seen with a high dose of diazepam. Convulsions induced by an agonist of another excitatory amino acid receptor subtype, kainate, were also inhibited by EtOH. An uncompetitive antagonist of NMDA receptors, 5-methyl-10,11-dihydro-5H-dibenzocyclohepten-5,10-imine maleate (MK-801), potentiated EtOH-induced loss of righting, but attenuated the hypothermic action of EtOH. Moreover, MK-801 inhibited audiogenic convulsions in EtOH withdrawn rats. At the same time the effect of a proconvulsive dose of NMDA was not enhanced. Tolerance to the myorelaxant action of both EtOH and MK-801 upon repetitive administration was seen. Also some degree of cross-tolerance was observed. Moreover, MK-801 failed to modify EtOH preference in rats. The present results support involvement of NMDA receptors in expression of some acute and subchronic actions of EtOH and in expression of EtOH withdrawal.

Alcohol Drinking↗
PubMed1991

Chronic oral treatment with diltiazem or verapamil decreases isolation-induced activity impairment in elevated plus maze.

Adult male Wistar rats were either socially isolated or group-housed for 6 weeks and then tested in an elevated plus maze. During isolation the rats received either water or two concentrations of the calcium channel inhibitors, diltiazem or verapamil, in drinking solutions (approximately 5 and 10 mg/kg daily). Isolated rats showed a significantly lower total number of arm entries, a lower percentage of open arm entries and negligible time spent therein than did group-housed animals. Verapamil, in the higher dose, prevented that effect of isolation. Treatment with diltiazem brought about a similar tendency, though the effect did not reach statistical significance. Chronic treatment of group-housed rats with either drug failed to influence their behavior in the plus maze. We conclude that certain calcium channel inhibitors may decrease the behavioral deficit in the elevated plus maze that follows chronic social isolation.

Animals↗
PubMed1991

[Prognostic value of measuring serum angiotensin I-converting enzyme (ACE) in patients with sarcoidosis].

Serum ACE (s-ACE) activity were determined in 112 sarcoid patients and 60 healthy volunteers. The mean s-ACE activity in sarcoid patients were 39.5 +/- 14.1 U. and in healthy volunteers 22.1 +/- 3.6, U. Significant increase of s-ACE was seen in active sarcoidosis 51.2 +/- 13.7 U. Serum ACE activity increased twice or more in comparison with control values imply activity of the process. Serum-ACE determination may be of use as a prognostic factor in sarcoidosis.

Adolescent↗