A pharmacological study of dopaminergic receptors in planaria.
The dopaminergic receptors of planaria have been studied with pharmacological and biochemical criteria. Dopamine D1 selective agonists (CY 208243 (10 micrograms/ml) and SKF 38393 (10 micrograms/ml] induced in planaria typical screw-like hyperkinesias, that were inhibited by a D1 antagonist (SCH 23390 (10 micrograms/ml], but not by a D2 antagonist (sulpiride (1000 micrograms/ml]. Dopamine D2 selective agonists (PHNO (5 micrograms/ml), lisuride (5 micrograms/ml] on the contrary induced a typical "C" like curling, that was inhibited by pretreatment with D2 selective blocking agents, but not by D1 selective blocking agents. With agonists with a D1/D2 mixed action (apomorphine 60 micrograms/ml) or with amphetamine (100 micrograms/ml), the D1 type movements appeared to be more evident. Dopamine D1-selective agonists, mixed action agonists or D2-selective agonists, all induced a significant increase in levels of cAMP, that was prevented by pretreatment with the specific DA blocking agent.
Venturini
G
G
Department of Neurological Sciences, University of Roma La Sapienza, Italy.
Stocchi
F
F
Margotta
V
V
Ruggieri
S
S
Bravi
D
D
Bellantuono
P
P
Palladini
G
G
D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D009043:Motor Activity / Q000187:drug effects; D010932:Planarians / Q000187:drug effects* / Q000378:metabolism; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D014419:Turbellaria / Q000187:drug effects*
D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D000242:Cyclic AMP