Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLAXEDIL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1980

Evolution of cholinergic proteins in developing slow and fast skeletal muscles in chick embryo.

1. The cholinergic differentiation of two phenotypically muscles of the chick, the slow multiply innervated anterior latissimus dorsi (a.l.d.) and the fast focally innervated posterior latissimus dorsi (p.l.d.), was investigated during embryonic life and after hatching using both autoradiographical and biochemical methods. 2. The contents in total protein and in acetylcholinesterase activity follow similar development patterns in both muscles, but, after the 15th day in ovo, the accumulation of choline acetyltransferase activity and of acetylcholine nicotinic receptor sites as determined by alpha-bungarotoxin binding occurs at a faster rate in a.l.d. than in p.l.d. 3. In muscle of the p.l.d., a rapid increase of the total number of acetylcholine receptor clusters takes place after the 11th day of embryonic life although some clusters could be observed on myofibres as soon as the 4th day in ovo. 4. The rate of degradation of cholinergic receptor sites in chick muscle is constant around 28 hr up to the 10th day after hatching; thus the different rates of accumulation of acetylcholine receptor in a.l.d. and p.l.d., respectively, after the 15th day of embryonic life must be due to different rates of receptor synthesis. 5. The role of muscle activity in the biochemical differentiation of the developing motor end-plate was investigated in chick embryos which had been paralysed by repeated injections into the yolk sac of a curare-like agent, Flaxedil (May & Baker). 6. The total content in acetylcholinesterase of both a.l.d. and p.l.d. muscles is not significantly modified by paralysis. However, the histochemical staining of end-plates for acetylcholinesterase as well as the heavy form of this enzyme (19 . 5 S) are consistently reduced after Flaxedil injection. 7. In muscles from Flaxedil-treated embryos, the total content in acetylcholine receptor sites as determined by alpha-bungarotoxin binding is higher than in those from control embryos, whereas the rate of degradation of these sites is not significantly altered. 8. The localization of the acetylcholine receptors under the motor nerve terminals is not prevented by blocking muscle activity at the postsynaptic level. Clusters of receptor are still present, and there is no significant change in the number and distribution of these clusters along the myofibres of a.l.d. and p.l.d. muscles. 9. These results are discussed with respect to motor end-plate formation in multiply and focally innervated embryo muscles, and in relation to the control of cholinergic proteins distribution and synthesis by muscle activity.

Acetylcholine↗
PubMed1991

Effects of some potassium channel blockers on the ionic currents in myelinated nerve.

The effects of some potassium channel blockers on the ionic currents and on the so-called K(+)-depolarization in intact myelinated nerve fibres were studied. 4-AP, and in particular, Flaxedil, proved to be selective K(+)-current blockers. However, TEA, a crown ether (DCH18C6), a longchained triethylammonium compound (C10-TriEA), capsaicin, and the extract from the medicinal herb Ruta graveolens proved not to be selective K(+)-current blockers; they all block Na(+)-currents as well, although to a lesser extent. The sodium inactivation curve did not change under TEA and Flaxedil but was shifted on the potential axis in negative direction by DCH18C6, 4-AP, capsaicin and the Ruta extract whereas C10-TriEA caused a shift of both sodium inactivation and activation parameters in positive direction. Regarding to the kinetics of the persisting K(+)-current fraction, two different kinds of blockade were found: 1. Unchanged K(+)-kinetic which is typical for the effects of TEA, 4-AP, Flaxedil, and C10-TriEA. 2. Clearly changed K(+)-kinetic, characterized by K(+)-transients; which is typical for the effects of capsaicin and in particular, for those of DCH18C6 and of the Ruta extract. The possibly different modes of action of both groups of blockers are discussed in terms of current models for the action of potassium channel blockers.

4-Aminopyridine↗
PubMed1987

Circling behavior in honey bees.

Unilateral microinjections of gamma-aminobutyric acid (GABA), acetylcholine (ACh) and related substances into central parts of the brain of the honey bee elicit a quantifiable circling behavior. GABA (40 nl, 10(-2) M, muscimol (40 nl, 10(-4) M) and flaxedil (10(-3) M, 40 nl) induce contralateral circling whilst ACh (40 nl, 10(-2) M), nicotine (40 nl, 10(-4) M) and picrotoxin (40 nl, 10(-3) M) induce ipsilateral circling if injected in the proximity of the alpha-lobe (50-100 microns) of the of the mushroom body. Mechanical lesions of the pedunculus induce ipsilateral circling. This can be reversed by ipsilateral injections of GABA and flaxedil. Intracellular recordings demonstrate a hyperpolarizing effect of GABA and a depolarising effect of ACh on individual neurons in this region. These results suggest that circling behavior in the bee is controlled by the balance of GABA in the alpha-lobes and mediated by acetylcholinergic neurons.

Acetylcholine↗
PubMed1987

Rhythmicity as an intrinsic property of the mormyrids electromotor command system.

The timing of electromotoneuron discharges was investigated in weak-electric mormyrid fish (Gnathonemus petersii) after suppression of electrosensory feedback by injection of FLAXEDIL. FLAXEDIL, a paralytic agent, momentarily silenced the electric organs, removing the autostimulation of the fish's electroreceptors by its own discharge. It is shown that in such conditions: (1) the electromotor output was cyclic; (2) the time intervals separating discharges belonged mostly to two distinct categories; (3) the first category was centred in all fish around 100 msec; (4) the second category fluctuated depending on the individuals between 250 and 400 msec; (5) the different types of time intervals did not follow each other at random; (6) their serial ordering presented inter-individual differences. A rhythmic pattern was thus demonstrated in the absence of a feedback time-locked to the motor command, bringing evidence that rhythmicity results from the intrinsic activity of the electromotor command system. This pattern showed many similarities with that recently described in immobile and undisturbed discharging fish, leading us to postulate that the mormyrid electromotor output is organised by a central pattern generator (CPG). It is suggested that peripheral control, achieved through the use of electrosensory feedback, serves to increase the variability of the rhythms of discharge, so that they are adapted to the situation in which the fish participates.

Animals↗
PubMed1983

Differential pattern of sympathetic outflow during upper airway stimulation with smoke.

This study investigates directly the possibility that sympathetic discharge to the heart is decreased while it is increased to other organs during upper respiratory perfusion with cigarette smoke. Blood pressure (BP), heart rate, ECG, and respiratory movements were monitored in urethane-anesthetized rabbits. Insertion of two cannulas allowed respiration of room air while passing smoke across the upper respiratory irritant receptors and out through the nares. Through a retroplural incision, the left stellate ganglion was exposed and a cardiac branch isolated. Similarly, a left renal nerve was isolated. Multiunit nerve recordings were obtained from both nerves. In four control animals, cigarette smoke (50 ml) caused apnea, bradycardia (-116 beats/min) and increased BP (33 mmHg). Activity in the renal nerve increased (248% of control [C]) and activity in the cardiac nerve was reduced (62% C). In these animals after Flaxedil and artificial respiration, nerve activity responses were still pronounced (renal, 178% C; cardiac, 66% C). In four other barodenervated animals neural responses to smoke were similar to those observed with baroreceptors intact (renal, 211% C; cardiac, 51% C). In these animals after artificial ventilation and Flaxedil, responses were not significantly changed. These results indicate that smoke stimulation causes a differential pattern of sympathetic discharge. The responses observed cannot be accounted for by secondary adjustments through arterial baroreceptors, chemoreceptors, or pulmonary stretch receptors.

Animals↗