Antinociceptive modulation by the adhesion GPCR CIRL promotes mechanosensory signal discrimination.

Adhesion-type GPCRs (aGPCRs) participate in a vast range of physiological processes. Their frequent association with mechanosensitive functions suggests that processing of mechanical stimuli may be a common feature of this receptor family. Previously, we reported that the aGPCR CIRL sensitizes sensory responses to gentle touch and sound by amplifying signal transduction in low-threshold mechanoreceptors (Scholz et al.

Pain perception and cardiovascular system response among athletes playing contact sports.

The aim of this study was to determine whether the contact sports change the perception of pain as assessed by the cold pressor test (CPT), and if the test induces the same reaction of the cardiovascular system in contact athletes and non-athletes. The study involved 321 healthy men; 140 contact athletes and 181 students of the University of Szczecin (control). Pain threshold and pain tolerance were evaluated using CPT.

High-magnitude whole-body vibration effects on bone resorption in adult rats.

Introduction: Optimal parameters of whole-body vibration (WBV), effective in increasing bone mass or preventing bone loss, are always being sought. We investigated effects of a 6-mo WBV program, consisting of brief daily vibratory sessions, on the bone mass and bone metabolic markers.

Methods: There were 10 male Wistar rats (3 mo old) that were subjected to the 6-mo WBV (frequency 50 Hz, acceleration 4.

Low-volume whole-body vibration lasting 3 or 6 months does not affect biomarkers in blood serum of rats.

Whole-body vibration training (WBV) has been reported to improve both, bone strength and neuromuscular performance. Although changes in hormonal and immunological parameters following vibration exercises were reported, there are still few studies concerning the immune response with respect to different duration of WBV. In our study, we aimed to establish whether three and six months of specific, short-lasting WBV (four bouts lasting 30 s, 1 min rest intervals) influences blood cell counts as well as some immunological parameters in rats.

Field hockey players have different values of ulnar and tibial motor nerve conduction velocity than soccer and tennis players.

The aim of this study was to describe motor nerve conduction velocity in upper and lower extremities in sportsmen. Fifteen high-level field hockey players, seventeen soccer players and ten tennis players were recruited from the Polish National Field Hockey League, Polish Soccer League Clubs, and Polish Tennis Association clubs,respectively. The control group comprised of seventeen healthy, non-active young men.

Complex myograph allows the examination of complex muscle contractions for the assessment of muscle force, shortening, velocity, and work in vivo.

Background: The devices used for in vivo examination of muscle contractions assess only pure force contractions and the so-called isokinetic contractions. In isokinetic experiments, the extremity and its muscle are artificially moved with constant velocity by the measuring device, while a tetanic contraction is induced in the muscle, either by electrical stimulation or by maximal voluntary activation. With these systems, experiments cannot be performed at pre-defined, constant muscle length, single contractions cannot be evaluated individually and the separate examination of the isometric and the isotonic components of single contractions is not possible.

Assessment of precision and reproducibility of a new myograph.

Background: The physiological characteristics of muscle activity and the assessment of muscle strength represent important diagnostic information. There are many devices that measure muscle force in humans, but some require voluntary contractions, which are difficult to assess in weak or unconscious patients who are unable to complete a full range of voluntary force assessment tasks. Other devices, which obtain standard muscle contractions by electric stimulations, do not have the technology required to induce and measure reproducible valid contractions at the optimum muscle length.

In vivo myograph measurement of muscle contraction at optimal length.

Background: Current devices for measuring muscle contraction in vivo have limited accuracy in establishing and re-establishing the optimum muscle length. They are variable in the reproducibility to determine the muscle contraction at this length, and often do not maintain precise conditions during the examination. Consequently, for clinical testing only semi-quantitative methods have been used.

Octreotide, a somatostatin analogue, attenuates movement evoked discharges of fine afferent units from inflamed knee joints of rats.

This electrophysiological study examined whether octreotide, a stable analogue of somatostatin (SOM), reduces the mechanosensitivity of fine primary afferents from inflamed knee joints of rats similarly to SOM itself (Pain 73 (1997) 377). Close intra-arterial application of 200 microl of octreotide (10(-6)-10(-3) M) dose-dependently diminished the responses to passive non-noxious and noxious rotations of the joint in most of the units tested. The inhibitory effects of octreotide required a higher concentration (10(-3) M) compared to SOM to successfully decrease the number of recorded spikes.

Effects of different molecular weight elastoviscous hyaluronan solutions on articular nociceptive afferents.

Objective: To compare 3 different hyaluronan (HA) preparations used as therapeutic agents for osteoarthritis pain in humans in order to establish the degree to which a single application affects the sensitivity of nociceptors in both the normal and the acutely inflamed rat joint.

Methods: In anesthetized rats, single-unit recordings were performed from the medial articular nerve of the right knee joint under normal conditions and during an acute experimental arthritis. Fifty fine afferent units (conduction velocities 0.

Gabapentin reduces the mechanosensitivity of fine afferent nerve fibres in normal and inflamed rat knee joints.

The antiepileptic drug gabapentin has been shown to have an antihyperalgesic effect following central administration. This electrophysiological investigation examined whether peripherally administered gabapentin could modulate the mechanosensitivity of primary afferents innervating normal and kaolin/carrageenan inflamed rat knee joints. Close intraarterial injection of gabapentin (0.

The neurokinin-2 receptor is not involved in the sensitization of primary afferents of the rat knee joint.

Using electrophysiological methods, we aimed in the present study to determine whether the NK(2) receptor is involved in the sensitization of articular afferents of the rat. Impulse activity from 27 single fine nerve fibres innervating knee joints was recorded during non-noxious and noxious joint rotations. Close intraarterial application of the NK(2) receptor agonist [beta-Ala(8)]NKA(4-10) at doses of 0.

Inhibitory effect of somatostatin on the mechanosensitivity of articular afferents in normal and inflamed knee joints of the rat.

The effect of somatostatin on the sensory activity of primary afferents was studied in normal and acutely inflamed rat knee joints. Fine afferent nerve fibers with conduction velocities of 0.9-18.

Responsiveness of slowly conducting articular afferents to bradykinin: effects of an experimental arthritis.

Bradykinin (BK), an important inflammatory mediator and potent algogenic substance, is supposed to contribute to the generation of arthritic hyperalgesia and pain. The present study was undertaken to examine if an experimental kaolin/carrageenan arthritis sensitizes articular afferents to BK in the cat's knee joint using two different approaches. First, the proportion of afferent units activated by BK was assessed in fully inflamed joints and compared with corresponding data of normal knee joints.