Receptor agonists action

It is an ergot preparation which has a specific dopamine receptor agonist action (acts mainly on receptors) and capable of crossing the blood brain barrier. It is less active than levodopa and used only in late cases as a supplement to levodopa. Adverse effects are vomiting hallucinations, hypotension, nasal stuffiness. 

Other sympathomimetics may be used as judgement counsels, according to the desired receptor agonist actions (Pj, P, a) required by the clinical condition, e.g. dobutamine, dopamine, dopexamine, noradrenaline, adrenaline. 

Pharmacodynamic. The effect on the blood pressure of s5unpathomimetics having both a- and P-receptor agonist actions is increased by block of p-... 

Anxiolytics are drugs used for the treatment of anxiety disorders. Apart from benzodiazpines, a frequently used anxiolytic is the 5HT1A (serotonin) receptor agonist buspiron, which has no sedative, amnestic or muscle-relaxant side effects, but whose action takes about a week to develop. Furthermore, it is less efficaceous than the benzodiazepines. Buspiron s mechanism of action is not fully understood. 

The binding site for barbiturates on the GABAa receptor is less well defined. Barbiturates act by increasing the conductance level. In contrast to benzodiazepines, they also display direct agonistic action on GABAa receptors. Also in contrast to... 

Glaum SR, Miller RJ, Hammond DL (1994) Inhibitory actions of delta 1-, delta 2-, and mu-opioid receptor agonists on excitatory transmission in lamina II neurons of adult rat spinal cord. 

KINETICS AND MECHANISMS OF AGONIST ACTION (a) Ion channel receptors... 

Mimic the action of DA with appropriate DA receptor agonists... 

The relative extent of the unwanted effects caused by selective agonists at the different opioid receptors is of great importance in determining if non-mu opioids will have better spectra of actions as compared to morphine. However, there are good indications that the kappa and delta receptor agonists cause less respiratory depression than mu... 

Administration of 5-HTib receptor agonists increases waking time and reduces REM sleep. This is consistent with recent evidence gathered from 5-HTiB-receptor knockout mice which exhibit more REM sleep and less SWS than the wild-type. Moreover, 5-HTib agonists reduce, while antagonists increase, REM sleep in the wild-type mouse, but neither type of compound has any effect in the knock-outs (Boutrel et al. 1999). Unfortunately, it is not known whether these actions are mediated by presynaptic, postsynaptic or heteroceptors and therefore whether 5-HT activity is increased or decreased. It is also not helped by the limited selectivity of test agents. 

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