[How do we explain the antihypertensive effect of bromocriptine? Clinical and experimental contribution].
The mechanism of the antihypertensive properties of bromocriptine was investigated in dog and man. In anaesthetized dogs, bromocriptine induced a decrease in the pressor responses to adrenaline or phenylephrine and reduced the hypotensive properties of clonidine. In 6 hypertensive patients with Parkinson's disease, chronic treatment with bromocriptine (46.4 +/- 12.0 mg/day) elicited both a significant decrease in blood pressure and an improvement of extrapyramidal symptoms. During bromocriptine therapy, domperidone (60 mg/day during 1 month), a specific peripheral dopaminergic antagonist was introduced. The drug did not change the levels of blood pressure (before domperidone: 150.8 +/- 22.5/79.9 +/- 8.9 mmHg after domperidone: 150 +/- 17.3/87.5 +/- 12.9 mmHg). These results confirm the antihypertensive properties of bromocriptine and demonstrate that, beside their dopaminergic properties, the drug also possesses mixed alpha 1 and alpha 2 adrenolytic actions. These two properties may contribute to the mechanism of the antihypertensive effects of bromocriptine. These data also show that domperidone can be used in bromocriptine-treated hypertensive parkinsonians without side effects on blood pressure.
D000317:Adrenergic alpha-Antagonists; D000368:Aged; D000818:Animals; D000959:Antihypertensive Agents; D001971:Bromocriptine / Q000494:pharmacology* / Q000627:therapeutic use; D004285:Dogs; D004294:Domperidone / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000037:antagonists & inhibitors; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications; D011954:Receptors, Dopamine / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D000959:Antihypertensive Agents; D011954:Receptors, Dopamine; D001971:Bromocriptine; D004294:Domperidone; D004837:Epinephrine
Comment expliquer l'effet antihypertenseur de la bromocriptine? Contribution clinique et expérimentale.