Dopamine, serotonin and alpha-adrenergic receptor blocking activities in serum and their relationships to prolactin level in schizophrenic patients receiving long-term chlorpromazine treatment.
The clinical application of a dopamine radioreceptor assay for neuroleptics has been proposed. Simultaneous monitoring of serum antidopaminergic (anti-DA), antiserotonergic (anti-5HT) antiadrenergic (anti-NA) activities may provide a better understanding of clinical effects of neuroleptics. Serum anti-DA and anti-5HT activities were estimated by competition for 3H-spiperone binding to dopamine and serotonin receptors in rat brain, respectively, and anti-NA activity by competition for 3H-WB-4101 binding to alpha-receptors. Thirty-one patients receiving maintenance doses of chlorpromazine (CPZ) chronically were studied. Serum activities varied among patients receiving the same dose, but correlated significantly with dose. Anti-DA activity also correlated with both anti-5HT anti-NA activities, and the average ratio of anti-5HT or anti-NA to anti-DA activity was slightly reduced by metabolism of CPZ. However, some patients had a different spectrum of serum activities from that of in vitro activities. Serum prolactin (PRL) correlated weakly with all the serum activities. The serum PRL anti-DA activity ratio appeared to be independent of anti-5HT or anti-NA activity, suggesting the predominant involvement of anti-DA activity in the stimulation of PRL release.
D000317:Adrenergic alpha-Antagonists; D000328:Adult; D000368:Aged; D002746:Chlorpromazine / Q000097:blood / Q000627:therapeutic use*; D002908:Chronic Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D011388:Prolactin / Q000097:blood*; D011869:Radioligand Assay; D011954:Receptors, Dopamine / Q000187:drug effects*; D011985:Receptors, Serotonin / Q000187:drug effects*; D012559:Schizophrenia / Q000097:blood* / Q000188:drug therapy
D000317:Adrenergic alpha-Antagonists; D011954:Receptors, Dopamine; D011985:Receptors, Serotonin; D011388:Prolactin; D002746:Chlorpromazine