Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of two beta 2-adrenoceptor agonists with different lipophilicities were studied on tremor induced by L-5-hydroxytryptophan (L-5-HTP) in pargyline- and carbidopa-pretreated rats. Tremor was recorded and analysed by an objective method based on accelerometry. Clenbuterol, a lipophilic beta 2-selective agonist, dose-dependently enhanced tremor intensity, whereas the hydrophilic beta 2-agonist terbutaline had no effect. The clenbuterol-induced enhancement of tremor was completely abolished by the beta 2-selective antagonist ICI 118,551 but unchanged by the beta 1-selective antagonist metoprolol. The results suggest that centrally located beta 2-adrenoceptors can mediate a modulation of 5-hydroxytryptamine-induced tremor in rats.
 ...
PMID:Central beta-adrenoceptors can modulate 5-hydroxytryptamine-induced tremor in rats. 286 14

In a double-blind cross-over study of 33 marksmen (standard pistol, 25 m) the adrenergic beta 1-receptor blocker, metoprolol, was compared to placebo. Metoprolol obviously improved the pistol shooting performance compared with placebo. Shooting improved by 13.4% of possible improvement (i.e., 600 points minus actual points obtained) as an average (SE = 4%, 2P less than 0.002). The most skilled athletes demonstrated the clearest metoprolol improvement. We found no correlation between the shooting improvement and changes in the cardiovascular variables (i.e., changes of heart rate and systolic blood pressure) and no correlation to the estimated maximum O2 uptake. The shooting improvement is an effect of metoprolol on hand tremor. Emotional increase of heart rate and systolic blood pressure seem to be a beta 1-receptor phenomenon.
 ...
PMID:beta-Blockade used in precision sports: effect on pistol shooting performance. 287 53

Tranylcypromine (TCP) pretreatment was found to accelerate the tremorogenic activity of tremorine in rats. Conversely, reserpinization delayed the onset of induction of tremors, and a significant diminution in their intensity was observed in these rats. A comparative study of the antitremor activity of beta-adrenoceptor antagonists against this tremor-model showed that butoxamine (beta 2-antagonist) and propranolol (nonselective antagonist) were able to afford a rapid and powerful protection, whereas a weaker and delayed effect was observed in rats treated with the beta 1-antagonist, acebutolol. Furthermore, the antitremor activity of butoxamine and propranolol but not that of acebutolol was found to be potentiated and diminished in rats pretreated with reserpine and TCP, respectively. It was inferred that beta 2-receptor modulated the tremorogenic activity of tremorine, and that inhibition by propranolol or butoxamine of this subtype beta-adrenoceptor resulted in rapid and powerful suppression of tremors, and that the antiadrenergic activity of acebutolol was unlikely to have a role in its antitremor effect.
 ...
PMID:The role of adrenergic mechanism in tremorine-induced tremors in rats: antitremor effect of beta-adrenoceptor antagonists. 288 20

The muscarinic agonist oxotremorine was used to induce tremor in rats pretreated with methylatropine. An objective assessment of tremor intensity was accomplished by means of an accelerometer-based recording system. The non-selective, lipophilic beta-adrenoceptor antagonist propranolol dose-dependently suppressed tremor intensity, whereas the R-isomer of propranolol was without effect, verifying beta-adrenoceptor involvement. Since the hydrophilic, non-selective beta-antagonist nadolol was ineffective, the effect appears to be located inside the blood-brain barrier. The beta 2-selective antagonist ICI 118, 551 dose-dependently reduced tremor intensity, whereas selective blockade of beta 1-adrenoceptors with metoprolol had no effect, indicating the participation of a beta 2-adrenoceptor. On the other hand, the lipophilic beta 2-agonist clenbuterol dose-dependently enhanced tremor induced by oxotremorine. Determination of circulating plasma catecholamine concentrations revealed that the effect of beta-antagonists on tremor was not secondary to an effect on the oxotremorine-induced rise in catecholamine levels. Thus, the results suggest that beta 2-adrenoceptors located inside the blood-brain barrier are able to modulate oxotremorine-induced tremor in rats.
 ...
PMID:Modulation of oxotremorine-induced tremor by central beta-adrenoceptors. 288 11

The effect of beta-adrenoceptor antagonists, varying in lipophilicity and receptor selectivity, were studied on tremor elicited by L-5-hydroxytryptophan (L-5-HTP) in rats pretreated with a peripherally acting decarboxylase inhibitor and a monoamine oxidase inhibitor, or by the directly acting 5-HT agonist 5-methoxy-N,N-dimethyltryptamine (5-MeODMT). Plasma levels of the beta-adrenoceptor antagonists were determined simultaneously. The non-selective lipophilic adrenoceptor antagonist propranolol was found to dose-dependently reduce tremor intensity, whereas the non-selective hydrophilic adrenoceptor antagonist sotalol had no effect, indicating a central site of action. Furthermore, beta 1-selective blockade with the adrenoceptor antagonist metoprolol had no effect on tremor intensity, whereas the beta 2-selective antagonist ICI 118,551 dose-dependently suppressed tremor intensity, suggesting that the beta-adrenoceptor subtype involved is of the beta 2-type. These results suggest that blockade of centrally located beta 2-adrenoceptors are able to attenuate the tremor response following 5-hydroxytryptamine receptor activation.
 ...
PMID:Blockade of central beta-adrenoceptors attenuates tremor induced by 5-hydroxytryptamine (5-HT)-receptor activation in rats. 288 12

Eight diabetics with autonomic neuropathy were given single oral doses of epanolol (200 mg), atenolol (50 mg), pindolol (5 mg) and placebo in a double-blind randomised order at weekly intervals. Supine resting heart rate, physiological tremor and blood glucose were measured before, 2 and 4 h after dosing, and ambulatory heart rate monitored for 24 h. Supine resting heart rate was significantly lowered by atenolol both at 2 and 4 h, and increased on pindolol at 4 h. Heart rate was unaffected by epanolol compared with placebo. Heart rate during the 'waking' period (14.00-23.00 h) was lower than placebo after epanolol and atenolol but unaffected by pindolol. During the 'sleeping' period (23.00 h-08.00 h) heart rate was significantly increased by pindolol, lowered with atenolol and unaffected on epanolol. Pindolol significantly increased physiological tremor at 4 h. No differences were seen between epanolol, atenolol and placebo. Plasma glucose was significantly increased by pindolol 2 h after dosing. These results suggest that pindolol probably produces its partial agonist activity at both beta 1- and beta 2-adrenoceptors, while the partial agonist activity of epanolol is beta 1-selective. Despite abnormal cardiovascular reflex tests in these diabetics, the heart rate responses obtained in this study after beta-adrenoceptor blockade were surprisingly normal, and suggest that the concept of 'cardiac denervation' in diabetes requires modification.
 ...
PMID:Effects of beta-adrenoceptor blockade on heart rate and physiological tremor in diabetics with autonomic neuropathy. A comparative study of epanolol, atenolol and pindolol. 288 87

1. The effects of single oral doses of three beta-adrenoceptor partial agonists (Ro 31-1118, flusoxolol and pindolol), two beta-adrenoceptor antagonists (propranolol and atenolol), two beta-adrenoceptor agonists (salbutamol and prenalterol) and placebo on sleeping heart rate, quality of sleep, supine heart rate, exercise heart rate, blood pressure, forearm blood flow and finger tremor were studied in eight healthy male volunteers. 2. Sleeping heart rate was increased by Ro 31-1118, flusoxolol, pindolol, salbutamol and prenalterol and decreased by propranolol and atenolol. 3. None of the drugs studied affected quality of sleep. 4. Supine heart rate was increased by flusoxolol, prenalterol and salbutamol, unaffected by Ro 31-1118 and pindolol and reduced by propranolol and atenolol. 5. Exercise heart rate was reduced by both beta-adrenoceptor antagonists and the three partial agonists and unaffected by salbutamol and prenalterol. 6. Systolic blood pressure was increased by Ro 31-1118, flusoxolol, salbutamol and prenalterol, unaffected by pindolol and reduced by propranolol and atenolol. Diastolic blood pressure was reduced by salbutamol and prenalterol. 7. Forearm blood flow was increased by Ro 31-1118, salbutamol and prenalterol, unchanged by pindolol and flusoxolol and decreased by atenolol and propranolol. 8. Finger tremor was increased by Ro 31-1118, flusoxolol, pindolol, salbutamol, and prenalterol. 9. beta-adrenoceptor partial agonists have different effects on the cardiovascular system and finger tremor to beta-adrenoceptor antagonists. 10. While Ro 31-1118 and flusoxolol are antagonists mainly at the beta 1-adrenoceptor they have agonist activity at both beta 1- and beta 2 adrenoceptors. 11. While pindolol is a non-selective antagonist its agonist activity is mainly at the beta 2-adrenoceptor.
 ...
PMID:An assessment of the partial agonist activity of Ro 31-1118, flusoxolol and pindolol in man. 289 34

1. The beta-adrenoceptor antagonist activity, cardioselectivity and antilipolytic properties of Koe 3290 were investigated in healthy subjects. 2. Koe 3290 12.5, 25, 50 and 100 mg, atenolol 25, 50 and 100 mg and placebo were given in double-blind randomised order to eight subjects. All doses of both Koe 3290 and atenolol reduced supine, standing and exercise heart rate (P less than 0.02). From 2 to 8 h after administration the exercise heart rate after Koe 3290 100 mg was similar to that for atenolol 50 mg. 3. The cardioselectivity of Koe 3290 and atenolol was compared. Koe 3290 50, 100 and 150 mg, atenolol 50 and 100 mg and placebo were given to six subjects in a double-blind random order. Isoprenaline dose-response curves were constructed for cardiovascular parameters and finger tremor. 4. For doses which were equipotent at the beta 1-adrenoceptor (Koe 3290 100 mg and atenolol 50 mg) atenolol caused less attenuation of heart rate, diastolic blood pressure, forearm blood flow and finger tremor (P less than 0.02). 5. There was no difference in the isoprenaline-induced changes in serum free fatty acids, blood glucose, plasma lactate or potassium after Koe 3290 and atenolol. Koe 3290 attenuated the rise in serum insulin more than atenolol (P less than 0.02). 6. Koe 3290 is an effective beta-adrenoceptor blocking drug in man. It is not as cardioselective as atenolol and does not possess specific antilipolytic properties.
 ...
PMID:The assessment of the beta-adrenoceptor blocking activity and cardioselectivity of Koe 3290 in normal subjects. 289 35

In a total of 36 volunteers with cardiac hyperreaction, investigations were carried out on the effect of bisoprolol (designated tradename: Concor), pindolol and placebo on central nervous functions with the aid of a reaction test, spiral aftereffect, tremor test and mood and sleep questionnaires. In the randomized double-blind study performed with 3 independent groups the volunteers received placebo, 2 X daily 10 mg of pindolol or 1 X daily 10 mg of bisoprolol for a period of 14 days. Bisoprolol is a new highly beta 1-selective adrenoceptor blocker with moderate lipophilia and without intrinsic sympathomimetic activity (ISA). When compared to placebo neither of the beta-adrenoceptor blockers induced any significant changes in mood, vigilance, tremor and reaction times. Moreover, under bisoprolol no negative effect on sleep quality or feeling refreshed after sleep was determined. Under pindolol, on the other hand, a significant impairment of sleep quality was observed after acute dosage and a decrease in feeling refreshed after sleep, continuing up to day 14 of treatment. It is presumed that, as bisoprolol and pindolol have comparable lipophilia, the different intensity with which the two preparations act on the central nervous system is connected with the ISA of pindolol. In the selected doses bisoprolol had a stronger effect on diastolic blood pressure and heart rate than pindolol and placebo.
 ...
PMID:[Comparative study of the central nervous system effect of the beta receptor blockaders pindolol and bisoprolol]. 293 54

To assess the partial agonist activity of cicloprolol in man, four studies were carried out in normal male volunteers. I and II. Open dose escalating studies of the effects of oral doses of the drug on exercise tachycardia and sleeping heart rate. III and IV. Double-blind randomized studies of the effects of placebo, cicloprolol 25 mg, cicloprolol 50 mg, cicloprolol 100 mg, atenolol 50 mg, pindolol 10 mg, salbutamol 8 mg and prenalterol 50 mg on sleeping heart rate, resting supine heart rate, blood pressure, forearm blood flow, finger tremor and exercise tachycardia. All doses of cicloprolol above 2.5 mg reduced an exercise tachycardia but there was no increase in effect above a dose of 50 mg. Cicloprolol caused a dose dependent increase in sleeping heart rate up to 200 mg. Cicloprolol increased resting supine heart rate, systolic blood pressure, forearm blood flow and finger tremor. None of the drugs affected quality of sleep. Cicloprolol has significant partial agonist activity at the beta 1-adrenoceptor as indicated by increases in heart rate and systolic blood pressure. The increases in finger tremor and forearm blood flow suggest that cicloprolol has some partial agonist activity at the beta 2-adrenoceptor.
 ...
PMID:Studies of the agonist and antagonist activity of cicloprolol in man. 316 10


<< Previous 1 2 3 4 5 Next >>