Dopamine agonist activity

There are also other non-monoaminergic alkaloids in some sacred plants which enhance catecholaminergic function. The white and blue water lilies, Nymphaea ampla and caerulea were employed as hallucinogens in both the Old and New worlds. These species contain apomorphine (an opiate with dopamine agonist activity), together with nuciferine and nornuciferine. 

In contrast, SK F 82526 is about ten times as potent as dopamine, and has about 1.6 times the maximal effect of dopamine as a renal vasodilator in anesthetized dogs. It causes a slight tachycardia, and at higher doses moderately decreases blood pressure. SK F 87516 is about three times as potent as, and shows about 80% of the maximal effect of dopamine as a renal vasodilator. However, it produces negligible blood pressure effects and exhibits a potent and profound bradycardiac effect suggesting that it may have presynaptic dopamine agonist activ-... 

An important criteria of D-l dopamine agonist activity is stimulation of dopamine-sensitive adenylate cyclase (8). Table I compares the activity of the four benzazepines and dopamine as stimulants of rat striatal adenylate cyclase. All of the benzazepines are only partial agonists with SK F 82526 and SK F 85174 being about 20 times more potent than dopamine and SK F 38393 and SK F 87516 being similar in potency to dopamine. 

A very intriguing observation noted above was the possibility of presynaptic dopamine agonist activity with SK F 87516 and SK F 85174. The inhibitions of the constrictor response and the 3H -norepinephrine release induced by brief intermittent periarterial sympathetic nerve stimulation of the perfused rabbit ear artery is a convenient in vitro assay for presynaptic dopamine agonist activity (30). In this preparation, both SK F 85174 and SK F 87516 inhibited both stimulation responses with an EC50 of about 100 riM. Another measure of D-2 activity is inhibition of specific spiroperidol binding (20). Comparison of these data (Table I) showed that SK F 85174 is thirty times as potent as dopamine, and thus is a potent D-2 agonist. However, the activity in adenylate cyclase stimulation indicates that this compound may be best described as a D-l/D-2 agonist (19, 20). 

Bromocriptine, pergolide, cabergoline Inhibit prolactin release Stop lactation inhibit growth of pituitary tumors Ergot alkaloid derivatives with potent dopamine agonist activity... 

Hydroxyaporphine can lower the blood pressure of cats. On the other hand, 8-hydroxy-A -w-propylnoraporphine shows no dopamine agonist activity. In fact, the C-10,11 diphenolic system does not seem to be a requirement for dopaminergic activity since 10-hydroxy- and 11-hydroxy-A - -propylnorapor-phine show appreciable activity in rats. j -Ethyl and iV- -propylnorapomor-phine are potent emetics in dogs. The hypotensive effect of apomorphine in the anesthetized cat was also observed with iV- -propylnorapomorphine. ... 

The diphenolic tertiary amine 43, structurally related to TV-w-propylnorapo-morphine ranks as a strong dopamine receptor agonist, and may thus find use in the treatment of Parkinson s disease. The dopamine agonist activity of apomorphine has been related to its shape and conformation. ... 

Clemens, J.A., Okimura, T. and Smalstig, E.B. (1993) Dopamine agonist activities of pergolide, its metabolites, and bromocriptine as measured by prolactin inhibition. 

Somei et d. also disclosed that ( )-6-nor-6-propyl-6,7-secoagroclavine [( )-7 2, KSU 1415] showed potent dopamine agonistic activity (50). 

Antipsychotics (conventional agents have nonspecific dopamine receptor antagonsim atypical agents also have serotonin antagonist activity), ecopipam, GBR-12909 and other partial dopamine agonists (may be functional antagonists)... 

A number of azetidine-based compounds have been disclosed in patent applications from Aventis Pharma for CBi-modulated treatment of diseases such as obesity, Parkinson s disease, schizophrenia, respiratory and neurological diseases [330-334]. Compound (556) was specifically claimed for use in two formulation patent applications [330, 331] for a stable semi-solid composition and oral emulsion composition, respectively. The optional coadministration of an agent that activates norepinephrinergic and se-rotoninergic neurotransmission (for example, sibutramine) or dopaminergic neurotransmission was also claimed for the treatment of obesity. The optional use of a dopamine agonist (for example, levodopa) was claimed... 

Aripiprazole was formulated in the early 1980s to function as a potential dopamine modulator, with both antagonist and agonist activity at the D2 receptor. It is the first D2 partial agonist available for the treatment of schizophrenia and is sometimes referred to as a third-generation antipsychotic. This novel mechanism is... 

Lagos P., Scorza C., Monti J. M. et al. (1998). Effects of the D3 preferring dopamine agonist pramipexole on sleep and waking, locomotor activity and striatal dopamine release in rats. Eur. Neuropsychopharmacol. 8(2), 113-20. 

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