Role of dopamine receptors in gastrointestinal motility.
Apomorphine (3.5 and 10 mg/kg, s.c.) and morphine (1.3 and 10 mg/kg, s.c.) produced a dose-dependent decrease in gastrointestinal transit of charcoal dust in rats. The involvement of dopamine in such a constipatory effect was found to be mediated to a greater extent by DA2 than by DA1 receptors, using a specific DA1 antagonist (SCH 23390) and DA2 antagonists (alizapride, domperidone). The decrease in apomorphine (50 micrograms) and dopamine (100 and 200 micrograms)-induced gastrointestinal transit after intracisternal administration was antagonized by haloperidol. These results provide evidence for the involvement of dopamine receptors in the constipatory effects of apomorphine and morphine in rats.
Dhasmana
K M
KM
Department of Anesthesiology, Erasmus University Medical Faculty, Rotterdam, The Netherlands.
Banerjee
A K
AK
Zhu
Y N
YN
Erdmann
W
W
Parmar
S S
SS
Salzman
S K
SK
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D004294:Domperidone / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology; D018492:Dopamine Antagonists; D004305:Dose-Response Relationship, Drug; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D005772:Gastrointestinal Transit / Q000187:drug effects; D006220:Haloperidol / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*
D001552:Benzazepines; D015259:Dopamine Agents; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D011954:Receptors, Dopamine; D004294:Domperidone; D009020:Morphine; D006220:Haloperidol; D001058:Apomorphine; C033968:alizapride