Adrenergic and dopaminergic properties of dopamine sulfoconjugates.
The 3- and 4-sulfate esters of dopamine (DA-3-SO4 and DA-4-SO4, respectively), the two main metabolites of DA, were evaluated for potential intrinsic or indirect catecholaminergic activities. Both compounds lacked any appreciable affinities for alpha 1, alpha 2, beta 1, beta 2 and DA-2 receptors. In the superfused [3H]norepinephrine-preloaded dog saphenous vein, both dopamine sulfates were devoid of any intrinsic inhibitory activity such as observed with dopamine pre- and postsynaptically. In addition, they did not displace the labeled vesicular neurotransmitter as did dopamine. In anesthetized dogs the two compounds failed to stimulate either the dopaminergic receptors (DA-1) of mesenteric vascular beds or the adrenergic receptors mediating the vasodilatory and pressor responses to dopamine.


CONCLUSIONS
In our experimental conditions DA-3-SO4 and DA-4-SO4, the products of dopamine sulfoconjugation, lacked any demonstrable intrinsic affinity and/or efficacy on the dopaminergic and adrenergic receptors directly or indirectly through their metabolic transformation or through displacement of endogenous neurotransmitter.
Kyncl
J J
JJ
Buckner
S A
SA
Brondyk
H
H
Kerkman
D J
DJ
DeBernardis
J F
JF
Bush
E N
EN
Kuchel
O
O
D000818:Animals; D004285:Dogs; D004298:Dopamine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000378:metabolism; D013152:Splanchnic Circulation / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011954:Receptors, Dopamine; C022807:dopamine 4-O-sulfate; C007558:dopamine 3-O-sulfate; D004298:Dopamine