Prehypertension is associated with increased cardiovascular events. While the "tracking phenomenon" is an important longitudinal characteristic of blood pressure (BP), changes in muscle sympathetic nerve activity (MSNA) over time remain unclear. This study tested the hypothesis that MSNA tracking contributes to BP trends in prehypertension. BP and MSNA were assessed in 13 prehypertensive males at rest, during hand grip and mental stressors at baseline and after 8 years. Baseline office BP averaged 127 ± 2/81 ± 2 mmHg and MSNA 24 ± 4 bursts/min. BP increased by 7 ± 2/5 ± 2 mmHg (P < 0.01) and MSNA by 11 ± 2 bursts/min (P < 0.001) at follow-up. SBP and DBP were interrelated at baseline (r = 0.65, P = 0.02) and at follow-up (r = 0.78, P = 0.002). MSNA tracking (r = 0.82; P < 0.001) was similar to BP. MSNA was strongly related to DBP at baseline (r = 0.73; P < 0.01) and follow-up (r = 0.64; P = 0.01), more so than SBP. BMI increased (P < 0.001) at follow-up but was unrelated to BP or MSNA. Despite comparable pressor and cardiac increases to handgrip and mental stressors, sympathetic responses were blunted, more pronounced to isometric test (P < 0.006) at follow-up. In conclusion, the trend in MSNA corresponds with BP changes over time suggesting that tonic sympathetic activation may contribute to time-related increase in resting BP and the development of sustained hypertension in prehypertension.

• Klíčová slova
• Heart-rate variability, laboratory stressors, muscle sympathetic nerve activity, prehypertension, pulse wave velocity, tracking,
• MeSH
• dospělí MeSH
• kohortové studie MeSH
• krevní glukóza analýza   MeSH
• krevní tlak * MeSH
• lidé MeSH
• lipidy krev   MeSH
• měření krevního tlaku MeSH
• prehypertenze krev   diagnóza   etiologie   patofyziologie   MeSH
• síla ruky MeSH
• srdeční frekvence MeSH
• svaly inervace   MeSH
• sympatický nervový systém patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• krevní glukóza MeSH
• lipidy MeSH

The miniature excitatory postsynaptic currents (MEPCs) of the muscle cells of the earthworm Lumbricus terrestris were recorded by glass microelectrodes. In a single synaptic zone, three types of MEPC were recorded: a fast single-exponential type that decayed with tau =0.9 ms, a slow single-exponential with tau = 9.2 ms and a two-exponential MEPC with tau = 1.3 and 8.5 ms, respectively. The muscle cells of earthworms contain populations of yet-unidentified ionic channels that might be different from the common nicotinic and muscarinic groups of acetylcholine receptors, since these MEPCs are not sensitive to d-tubocurarine, atropine, benzohexonium or proserine. Alternatively, besides ACh receptors, the membrane may contain receptors for another yet-unidentified excitatory transmitter.

• MeSH
• časové faktory MeSH
• cholinergní antagonisté farmakologie   MeSH
• excitační postsynaptické potenciály MeSH
• iontové kanály účinky léků   metabolismus   MeSH
• nervosvalové spojení účinky léků   metabolismus   MeSH
• nervový přenos * účinky léků   MeSH
• Oligochaeta metabolismus   MeSH
• svaly inervace   MeSH
• techniky in vitro MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cholinergní antagonisté MeSH
• iontové kanály MeSH

The early postdenervation depolarization of rat diaphragm muscle fibres (8-10 mV) is substantially smaller (3 mV) when muscle strips are bathed with 1 mM L-glutamate (GLU) or N-methyl-D-aspartate (NMDA). The effects of GLU and NMDA are not seen in the presence of aminophosphonovaleric acid (APV), a blocker of NMDA-subtype of glutamate receptors, 5 mM Mg2+ (which blocks NMDA-controlled ion channels) and L-nitroarginine methylester (NAME), an inhibitor of NO-synthase. This indicates that NMDA-subtype of GLU receptors might be involved in the regulation of the membrane potential in muscle fibres, most probably through the NO-synthase system.

• MeSH
• 2-amino-5-fosfonovalerát farmakologie   MeSH
• bránice fyziologie   MeSH
• denervace svalu MeSH
• krysa rodu Rattus MeSH
• kyselina glutamová farmakologie   MeSH
• membránové potenciály fyziologie   MeSH
• N-methylaspartát farmakologie   MeSH
• NG-nitroargininmethylester farmakologie   MeSH
• potkani Wistar MeSH
• receptory N-methyl-D-aspartátu fyziologie   MeSH
• svaly inervace   metabolismus   fyziologie   MeSH
• synthasa oxidu dusnatého antagonisté a inhibitory   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 2-amino-5-fosfonovalerát MeSH
• kyselina glutamová MeSH
• N-methylaspartát MeSH
• NG-nitroargininmethylester MeSH
• receptory N-methyl-D-aspartátu MeSH
• synthasa oxidu dusnatého MeSH

In the present study we describe the application of the non-specific cholinesterase (nChE) histochemical method for the detection of encapsulated sensory nerve endings prior to immunofluorescence staining of the sensory nerve fibres. The nChE staining of Schwann-derived structures surrounding sensory terminals allowed us to identify unequivocally the sensory corpuscles in the skin and the muscle proprioceptors (muscle spindles and Golgi tendon organs) in longitudinal sections of muscle tissue. The nChE staining of sensory nerve endings and immunofluorescence-labelled nerve fibres and their terminals could be viewed and photographed in the same section using appropriate filters. Since nChE activity persists in terminal Schwann cells for a long time after loss of the sensory axons, this combined enzyme- and immunohistochemical approach is also useful for experimental studies involving denervation and re-innervation of sensory nerve endings.

• MeSH
• cholinesterasy metabolismus   MeSH
• fluorescenční protilátková technika MeSH
• histocytochemie MeSH
• kočky MeSH
• krysa rodu Rattus MeSH
• kůže enzymologie   inervace   MeSH
• nervová zakončení enzymologie   MeSH
• neurony aferentní fyziologie   MeSH
• peptid spojený s genem pro kalcitonin imunologie   metabolismus   MeSH
• potkani Sprague-Dawley MeSH
• Schwannovy buňky enzymologie   MeSH
• spinální ganglia anatomie a histologie   MeSH
• substance P imunologie   metabolismus   MeSH
• svaly enzymologie   inervace   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cholinesterasy MeSH
• peptid spojený s genem pro kalcitonin MeSH
• substance P MeSH

Rat muscle spindles disintegrate after total neonatal muscle denervation in which both sensory and motor axons are cut, but develop almost normally during the first three weeks after neonatal de-efferentation, attaining the usual complement of four intrafusal fibres, two bag and two chain fibres. Thereafter additional intrafusal fibres differentiate in most of the de-efferented spindles. We have examined the development of supernumerary fibres in muscle spindles of the rat hind limb muscles one to four months after neonatal de-efferentation using transmission electron microscopy. Additional intrafusal fibres originate both from activated intrafusal myosatellites and by different forms of fibre division. In a sample of 27 muscle spindles examined along the A zone five weeks after de-efferentation, the mean number of intrafusal fibre profiles increased almost two-fold to 7.9 +/- 3.3 (S.D.). Up to 20 intrafusal fibre profiles per spindle cross-section were found in muscles de-efferented for four months. The supernumerary fibres were apparently derived from all three intrafusal fibre types, but predominantly from the chain fibres. It is noteworthy that de-efferentation which causes wasting of extrafusal muscle initiates myogenesis and maintains additional intrafusal fibres within the spindle capsules.

• MeSH
• denervace svalu * MeSH
• elektronová mikroskopie MeSH
• krysa rodu Rattus MeSH
• motorické neurony fyziologie   MeSH
• nervová vlákna fyziologie   ultrastruktura   MeSH
• neurony aferentní fyziologie   MeSH
• novorozená zvířata fyziologie   MeSH
• potkani Wistar MeSH
• svaly inervace   ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

1. Rat hemidiaphragms were incubated in a physiological low-K+ medium without stimulation and the amount of acetylcholine (ACh) released was measured radioenzymatically. Cholinesterases were inhibited by paraoxon. 2. In the presence of 1 microM tetrodotoxin (TTX), the amount of ACh released during a 2 h incubation was lowered by 40%. A similar decrease was observed in the absence of Ca2+ and in the presence of 10 microM-d-tubocurarine (dTC). The effects of TTX combined with Ca2+ removal, and of TTX combined with dTC were no greater than those of TTX, dTC or Ca2+ removal alone. TTX and dTC had no effect on the release of ACh from diaphragms 4 days after denervation. 3. The reduction of spontaneous ACh release observed in the presence of TTX or dTC or in the absence of Ca2+ is best interpreted on the assumption that about 40% of the ACh release was due to the impulse activity known to be generated in intramuscular motor nerve branches by the ACh which accumulates after the inhibition of cholinesterases. 4. In the presence of 1 and 10 microM vesamicol (AH5183, 2-(4-phenylpiperidino)-cyclohexanol), the release of ACh was also diminished by approximately 40%. Vesamicol did not augment the inhibition of release produced by TTX or by the omission of Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• acetylcholin metabolismus   MeSH
• bránice MeSH
• časové faktory MeSH
• chemická deprese MeSH
• cholinesterasy fyziologie   MeSH
• denervace MeSH
• depolarizující myorelaxancia farmakologie   MeSH
• krysa rodu Rattus MeSH
• piperidiny farmakologie   MeSH
• potkani Wistar MeSH
• svaly inervace   metabolismus   MeSH
• techniky in vitro MeSH
• tetrodotoxin farmakologie   MeSH
• tubokurarin farmakologie   MeSH
• vápník fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholin MeSH
• cholinesterasy MeSH
• depolarizující myorelaxancia MeSH
• piperidiny MeSH
• tetrodotoxin MeSH
• tubokurarin MeSH
• vápník MeSH
• vesamicol MeSH Prohlížeč

Serial recording of multimodal sensory (pattern reversal visual, brainstem auditory, median and tibial somatosensory) and motor evoked potentials during a 2-year period was performed on a group of 25 patients with relapsing multiple sclerosis. A new, 10-degree evoked potentials abnormality scale was introduced. In contrast to the insignificant common trend of both the mean individual EP latency parameters and the mean expanded disability status scale and evoked potentials abnormality scale to deteriorate the changes in both expanded disability status scale (p less than 0.05) and evoked potentials abnormality scale (p less than 0.01) were significant using a 1-point criterion for change and non-parametric testing. Changes in both scales differed in about 50% of patients; contrary to bidirectional changes in the clinical scale, no improvement in the evoked potential scale was found. The introduction of an evoked potentials abnormality scale based on separate cut-off step-like criteria may increase the robustness of evoked potential changes due to the activity of the disease in longitudinal studies.

• MeSH
• čití, cítění fyziologie   MeSH
• dospělí MeSH
• elektrická stimulace MeSH
• funkční lateralita fyziologie   MeSH
• lidé MeSH
• motorické neurony fyziologie   MeSH
• mozková kůra patofyziologie   MeSH
• mozkový kmen patofyziologie   MeSH
• nervus tibialis patofyziologie   MeSH
• reakční čas fyziologie   MeSH
• roztroušená skleróza diagnóza   patofyziologie   MeSH
• sluchové kmenové evokované potenciály fyziologie   MeSH
• somatosenzorické evokované potenciály fyziologie   MeSH
• svaly inervace   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• břišní svaly MeSH
• časové faktory MeSH
• elektrická stimulace MeSH
• psi MeSH
• svaly krevní zásobení   inervace   patologie   MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The sciatic nerve was crushed in the right hindlimb in newborn (3-8 h old) rats. Two to four months later, electromyographic activity was recorded from both the control and reinnervated ankle extensor muscles soleus or lateral gastrocnemius and from the ankle flexor muscle tibialis anterior. Tonic postural activity was present in the extensor muscles on both sides during quiet stance. The control flexor muscles were usually silent in this situation, but the reinnervated flexors exhibited abnormal sustained activity. During locomotion, the control extensors were activated during the stance phase and their mean burst made up 61.5% of the step cycle. The control tibialis anterior muscle fired only during the swing phase, with the burst lasting 18.1% of the step cycle. In the reinnervated extensor muscles, the mean burst duration was decreased (46% of the cycle) but the basic locomotor pattern was not impaired. The reinnervated tibialis muscle, however, was activated abnormally, with one appropriate flexor burst during the swing phase and an "extensor-like" burst during the stance phase of the step. Reflex responses to stretch were weak or absent on the operated side. Histological examination showed that the reinnervated soleus and tibialis muscles were almost devoid of muscle spindles. The motor unit mean firing rates in the reinnervated soleus (22 imp/s) and lateral gastrocnemius (45 imp/s) matched those of the control muscles (25 and 42 imp/s, respectively). In contrast to the phasic, high-frequency firing (52-80 imp/s) in the control tibialis, the reinnervated tibialis motor units fired at significantly lower rates (22-56 imp/s).(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• atrofie MeSH
• elektromyografie MeSH
• inbrední kmeny potkanů MeSH
• krysa rodu Rattus MeSH
• nervosvalová vřeténka ultrastruktura   MeSH
• nervus ischiadicus fyziologie   MeSH
• novorozená zvířata MeSH
• odpočinek MeSH
• pohybová aktivita fyziologie   MeSH
• reflex fyziologie   MeSH
• rozdrcení nervu * MeSH
• svaly inervace   patologie   fyziologie   MeSH
• zadní končetina fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Denervated fast-twitch rabbit muscles were progressively losing their fresh weight and the yield of sarcotubular protein was increasing. The activity of Ca(2+)-ATPase was affected but very slightly, the basal Mg(2+)-ATPase and the Mg(2+)-ATPase/Ca(2+)-ATPase ratio however increased together with a simultaneous depression of the membrane-bound acetylcholinesterase activity. We did not observe any differences in density properties of sarcotubular fractions between control and denervated muscle. However, a relative enrichment in SM and H fraction could be seen after denervation with small changes in the content of the Ca(2+)-pump protein, increased levels of calsequestrin and cholesterol, mostly in the heavy and the SM fraction. After denervation the binding sites for 3H-PN-200-110 did not show any changes in receptor affinity, but the number of putative Ca(2+)-channels increased twice along with a depression of 3H-ouabain binding sites. We suggest that the denervation of fast-twitch muscle leads to the hypertrophy of the junctional sarcoplasmic reticulum and the T-system. Changes in the cholesterol content, in the number of putative Ca(2+)-channels and in Na+, K(+)-ATPase can affect the muscle contraction.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• Ca(2+)-Mg(2+)-ATPasa metabolismus   MeSH
• Ca2+-ATPasy metabolismus   MeSH
• chemická frakcionace MeSH
• cholesterol analýza   MeSH
• denervace svalu * MeSH
• dihydropyridiny metabolismus   farmakologie   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• kalsekvestrin analýza   MeSH
• králíci MeSH
• sarkoplazmatické retikulum chemie   enzymologie   ultrastruktura   MeSH
• sodíko-draslíková ATPasa metabolismus   MeSH
• svalová kontrakce * MeSH
• svaly chemie   inervace   ultrastruktura   MeSH
• velikost orgánu MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1,4-dihydropyridine MeSH Prohlížeč
• acetylcholinesterasa MeSH
• Ca(2+)-Mg(2+)-ATPasa MeSH
• Ca2+-ATPasy MeSH
• cholesterol MeSH
• dihydropyridiny MeSH
• kalsekvestrin MeSH
• sodíko-draslíková ATPasa MeSH