Effects of dopaminergic agonists and antagonists on the serum prolactin levels in alcoholized rats.
A single dose of ethanol (1 g/kg p.o.) significantly decreased, whereas higher doses of ethanol (2 or 3 g/kg p.o.) significantly increased the serum prolactin (PRL) concentration. Administration of ethanol at a dose of 2 g/kg p.o. for 4 weeks did not affect this parameter but the ethanol withdrawal syndrome caused a significant rise in the serum PRL level. Chronic studies showed that D1-dopaminergic agonist SKF 38390 (2.5 mg/kg) significantly raised serum PRL levels in rats. This effect was reversed by long-lasting treatment of rats with ethanol and ethanol withdrawal. Pimozide (1 mg/kg), D2 antagonist, increased PRL in those rats. On the other hand, D1-antagonist SCH 23390 (0.5 mg/kg) and D2-agonist PPHT (0.5 mg/kg) were without effect in rats administered ethanol for a long period of time. In rats with ethanol withdrawal syndrome, administration of D1-antagonist SCH 23390 (0.5 mg/kg) also did not affect the serum PRL concentrations. However, D1-agonist SKF 38393 (2.5 mg/kg) and D2-antagonist pimozide (1 mg/kg) increased the serum PRL level in rats with ethanol withdrawal syndrome, whereas D2 agonist PPHT (2 mg/kg) decreased PRL level in serum. Thus, the acute effect of ethanol on PRL level appears to be dose-dependent. It seems that chronic ethanol administration and its withdrawal especially affected D1 receptor.
Samochowiec
J
J
Department of Clinical Neurobiology, Free University of Berlin, Germany.
Kleinrok
Z
Z
Jagiełło-Wójtowicz
E
E
Horodnicki
J
J
Rommelspacher
H
H
Schmidt
L G
LG
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000633:toxicity*; D018491:Dopamine Agonists / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004347:Drug Interactions; D000431:Ethanol / Q000008:administration & dosage / Q000633:toxicity*; D005947:Glucose / Q000494:pharmacology; D008297:Male; D010627:Phenethylamines / Q000494:pharmacology; D010868:Pimozide / Q000494:pharmacology; D011388:Prolactin / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar; D013375:Substance Withdrawal Syndrome / Q000097:blood* / Q000503:physiopathology
D001552:Benzazepines; D002492:Central Nervous System Depressants; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D010627:Phenethylamines; D010868:Pimozide; D000431:Ethanol; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; C041369:2-(N-phenethyl-N-propyl)amino-5-hydroxytetralin; D011388:Prolactin; D005947:Glucose