Possible mixed agonist--antagonist activity of D-sulpiride at dopamine receptor level in man.
The effects of different doses of D-sulpiride (1, 6, 12 and 25 mg, i.v.) on arterial blood pressure (ABP), heart rate (HR) and prolactin (PRL), growth hormone (GH), insulin and gastrin secretions have been studied in 8 normal men. D-Sulpiride increased systolic ABP with a maximum effect rather 12 mg i.v., while it had only slight effects on diastolic ABP and HR. PRL secretion was increased by D-sulpiride in a dose-dependent way, while insulin secretion was lowered and GH secretion slightly enhanced only in a restricted range of doses (6 mg and 12 mg i.v., respectively). Gastrin secretion seemed to be unaffected by D-sulpiride at any of the tested doses. These results are discussed in view of a possible mixed agonist--antagonist activity of D-sulpiride at dopamine receptor level in contrast with the relatively pure antagonistic action of the levo isomer.
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005755:Gastrins / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D011388:Prolactin / Q000378:metabolism; D011954:Receptors, Dopamine / Q000187:drug effects*; D013223:Statistics as Topic; D013469:Sulpiride / Q000494:pharmacology*
D005755:Gastrins; D007328:Insulin; D011954:Receptors, Dopamine; D013469:Sulpiride; D011388:Prolactin; D013006:Growth Hormone